| Seq | Timestamp | Type | Name | Duration |
|---|---|---|---|---|
| 0/0 | 2026/08/18 11:16 | flow | patch-triage |
2mArgs:null Results: {
"EnableConfigs": [
"NETCONSOLE",
"NETCONSOLE_DYNAMIC",
"CONFIGFS_FS"
],
"FocusSymbols": [
"ratelimit_interval_ms_store",
"ratelimit_burst_store",
"ratelimit_interval_ms_show",
"ratelimit_burst_show"
],
"KMSANReasoning": "The patch introduces rate limiting for netconsole targets. It adds `ratelimit_interval_ms` and `ratelimit_burst` configuration options, and uses `struct ratelimit_state` to track message rates. When messages are dropped, it sends a notice indicating the number of dropped messages.\n\nThe notice is formatted using `scnprintf` into the target's pre-allocated buffer (`nt-\u003ebuf`), and the exact length returned by `scnprintf` is passed to `send_udp`. `scnprintf` fully initializes the bytes it writes, and `send_udp` only reads the specified length, ensuring no uninitialized memory from the buffer is sent over the network.\n\nThe new fields in `struct netconsole_target` are properly initialized: `ratelimit` via `ratelimit_state_init`, and `pending_drops` is zero-initialized since the target structure is allocated with `kzalloc`.\n\nThere are no complex data structures with padding being copied to user space or sent over the network, nor is there any conditional logic depending on uninitialized variables. Any potential memory corruption, out-of-bounds access, or use-after-free bugs would be caught by KASAN. Therefore, a dedicated KMSAN fuzzing session is not required.",
"NeedsKMSAN": false,
"Reasoning": "The patch introduces rate limiting for netconsole targets to prevent a host from saturating the receiving agent with continuous logs. It adds new configfs attributes `ratelimit_interval_ms` and `ratelimit_burst` to configure the rate limit per target. The rate limiting logic is implemented in the console write path using `ratelimit_state`. The changes are reachable via configfs and the printk console write path. The configfs store/show functions are good candidates for fuzzing. The feature requires `CONFIG_NETCONSOLE`, `CONFIG_NETCONSOLE_DYNAMIC`, and `CONFIG_CONFIGFS_FS`.",
"WorthFuzzing": true
} |
| 1/1 | 2026/08/18 11:16 | action | read-patch-diff |
0mArgs:null Results: {
"PatchDiff": "commit 4906d8bd1febf63967491596728581965fa8da17\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Tue Aug 18 11:16:14 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst\nindex 4ab5d7b05cf10..7369cd89ae76c 100644\n--- a/Documentation/networking/netconsole.rst\n+++ b/Documentation/networking/netconsole.rst\n@@ -177,6 +177,49 @@ You can modify these targets in runtime by creating the following targets::\n cat cmdline1/remote_ip\n 10.0.0.3\n \n+Rate limiting\n+-------------\n+\n+Netconsole hands every console message to every enabled target, so a host that\n+logs continuously can saturate the receiving agent. Each target carries a token\n+bucket that drops messages once the configured rate is exceeded, controlled by\n+two files in the target directory:\n+\n+ ===================== ================================================\n+ ratelimit_interval_ms Length of the accounting interval, in\n+ milliseconds. Zero, the default, sends\n+ everything.\n+ ratelimit_burst Messages allowed per interval. Defaults to\n+ 10; zero drops every message.\n+ ===================== ================================================\n+\n+Unlike most target parameters, both knobs can be written while the target is\n+enabled, which is when a flooding target most likely needs them.\n+\n+The limit is applied per message, not per packet, so a message big enough to be\n+split into several `ncfrag` packets is either sent whole or not at all.\n+\n+Crash output bypasses the bucket. While an oops, BUG() or panic() is in\n+progress every message is sent, whatever the limit says, so a small burst\n+cannot cost you part of a crash dump.\n+\n+A drop leaves nothing on the wire, so the receiver is told what it missed as\n+soon as a message gets through again::\n+\n+ netconsole: 45 messages dropped by rate limit\n+\n+The notice only travels with the next message the bucket allows. A host that\n+goes quiet right after being limited reports the drops later, when it logs\n+again, and a target with a `ratelimit_burst` of zero never reports them.\n+\n+netconsole generates the notice itself instead of logging it, so on an\n+extended target the record carries a sequence number of zero.\n+\n+Capping a target at 500 messages a minute::\n+\n+ echo 60000 \u003e ratelimit_interval_ms\n+ echo 500 \u003e ratelimit_burst\n+\n Append User Data\n ----------------\n \ndiff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c\nindex b358e5c367351..0af2e5b4335c0 100644\n--- a/drivers/net/netconsole.c\n+++ b/drivers/net/netconsole.c\n@@ -49,6 +49,8 @@\n #include \u003clinux/rtnetlink.h\u003e\n #include \u003clinux/workqueue.h\u003e\n #include \u003clinux/delay.h\u003e\n+#include \u003clinux/ratelimit.h\u003e\n+#include \u003clinux/sched/clock.h\u003e\n \n MODULE_AUTHOR(\"Matt Mackall \u003cmpm@selenic.com\u003e\");\n MODULE_DESCRIPTION(\"Console driver for network interfaces\");\n@@ -175,6 +177,8 @@ struct netcons_userdata {\n * @sysdata:\t\tCached, formatted string of append\n * @sysdata_fields:\tSysdata features enabled.\n * @msgcounter:\tMessage sent counter.\n+ * @ratelimit:\tOpaque structure to ratelimit messages\n+ * @pending_drops: Messages dropped since the last notice was sent.\n * @stats:\tPacket send stats for the target. Used for debugging.\n * @state:\tState of the target.\n *\t\tVisible from userspace (read-write).\n@@ -219,6 +223,8 @@ struct netconsole_target {\n \tu32\t\t\tsysdata_fields;\n \t/* protected by target_list_lock */\n \tu32\t\t\tmsgcounter;\n+\tu32\t\t\tpending_drops;\n+\tstruct ratelimit_state\tratelimit;\n #endif\n \tstruct netconsole_target_stats stats;\n \tenum target_state\tstate;\n@@ -282,6 +288,34 @@ static void dynamic_netconsole_mutex_unlock(void)\n \tmutex_unlock(\u0026dynamic_netconsole_mutex);\n }\n \n+static void netconsole_ratelimit_init(struct netconsole_target *nt)\n+{\n+\tratelimit_state_init(\u0026nt-\u003eratelimit, 0, DEFAULT_RATELIMIT_BURST);\n+\tratelimit_set_flags(\u0026nt-\u003eratelimit, RATELIMIT_MSG_ON_RELEASE);\n+}\n+\n+static bool netconsole_ratelimited(struct netconsole_target *nt)\n+{\n+\t/* A limit meant for steady-state logging must not eat a crash dump. */\n+\tif (oops_in_progress)\n+\t\treturn false;\n+\n+\tif (__ratelimit(\u0026nt-\u003eratelimit))\n+\t\treturn false;\n+\n+\tnt-\u003epending_drops++;\n+\n+\treturn true;\n+}\n+\n+static u32 netconsole_take_drops(struct netconsole_target *nt)\n+{\n+\tu32 drops = nt-\u003epending_drops;\n+\n+\tnt-\u003epending_drops = 0;\n+\treturn drops;\n+}\n+\n #else\t/* !CONFIG_NETCONSOLE_DYNAMIC */\n \n static int __init dynamic_netconsole_init(void)\n@@ -318,6 +352,20 @@ static void dynamic_netconsole_mutex_unlock(void)\n {\n }\n \n+static void netconsole_ratelimit_init(struct netconsole_target *nt)\n+{\n+}\n+\n+static bool netconsole_ratelimited(struct netconsole_target *nt)\n+{\n+\treturn false;\n+}\n+\n+static u32 netconsole_take_drops(struct netconsole_target *nt)\n+{\n+\treturn 0;\n+}\n+\n #endif\t/* CONFIG_NETCONSOLE_DYNAMIC */\n \n /* Check if the target was bound by mac address. */\n@@ -686,6 +734,7 @@ static struct netconsole_target *alloc_and_init(void)\n \tnt-\u003eremote_port = 6666;\n \teth_broadcast_addr(nt-\u003eremote_mac);\n \tnt-\u003estate = STATE_DISABLED;\n+\tnetconsole_ratelimit_init(nt);\n \tINIT_WORK(\u0026nt-\u003eresume_wq, process_resume_target);\n \t/* Set up the skb pool primitives once; enabling only refills it. */\n \tskb_queue_head_init(\u0026nt-\u003eskb_pool);\n@@ -912,6 +961,21 @@ static ssize_t transmit_errors_show(struct config_item *item, char *buf)\n \treturn sysfs_emit(buf, \"%llu\\n\", xmit_drop_count + enomem_count);\n }\n \n+static ssize_t ratelimit_interval_ms_show(struct config_item *item, char *buf)\n+{\n+\tstruct netconsole_target *nt = to_target(item);\n+\n+\treturn sysfs_emit(buf, \"%u\\n\",\n+\t\t\t jiffies_to_msecs(READ_ONCE(nt-\u003eratelimit.interval)));\n+}\n+\n+static ssize_t ratelimit_burst_show(struct config_item *item, char *buf)\n+{\n+\tstruct netconsole_target *nt = to_target(item);\n+\n+\treturn sysfs_emit(buf, \"%d\\n\", READ_ONCE(nt-\u003eratelimit.burst));\n+}\n+\n /* configfs helper to display if cpu_nr sysdata feature is enabled */\n static ssize_t sysdata_cpu_nr_enabled_show(struct config_item *item, char *buf)\n {\n@@ -1307,6 +1371,50 @@ static ssize_t remote_mac_store(struct config_item *item, const char *buf,\n \treturn ret;\n }\n \n+static ssize_t ratelimit_interval_ms_store(struct config_item *item,\n+\t\t\t\t\t const char *buf, size_t count)\n+{\n+\tstruct netconsole_target *nt = to_target(item);\n+\tunsigned int interval;\n+\tunsigned long jifs;\n+\tssize_t ret;\n+\n+\tret = kstrtouint(buf, 10, \u0026interval);\n+\tif (ret)\n+\t\treturn ret;\n+\n+\tjifs = msecs_to_jiffies(interval);\n+\tif (jifs \u003e INT_MAX)\n+\t\treturn -ERANGE;\n+\n+\tdynamic_netconsole_mutex_lock();\n+\tWRITE_ONCE(nt-\u003eratelimit.interval, jifs);\n+\tdynamic_netconsole_mutex_unlock();\n+\n+\treturn count;\n+}\n+\n+static ssize_t ratelimit_burst_store(struct config_item *item, const char *buf,\n+\t\t\t\t size_t count)\n+{\n+\tstruct netconsole_target *nt = to_target(item);\n+\tunsigned int burst;\n+\tssize_t ret;\n+\n+\tret = kstrtouint(buf, 10, \u0026burst);\n+\tif (ret)\n+\t\treturn ret;\n+\n+\tif (burst \u003e INT_MAX)\n+\t\treturn -ERANGE;\n+\n+\tdynamic_netconsole_mutex_lock();\n+\tWRITE_ONCE(nt-\u003eratelimit.burst, burst);\n+\tdynamic_netconsole_mutex_unlock();\n+\n+\treturn count;\n+}\n+\n struct userdatum {\n \tstruct config_item item;\n \tchar value[MAX_EXTRADATA_VALUE_LEN];\n@@ -1671,6 +1779,8 @@ CONFIGFS_ATTR_RO(, local_mac);\n CONFIGFS_ATTR(, remote_mac);\n CONFIGFS_ATTR(, release);\n CONFIGFS_ATTR_RO(, transmit_errors);\n+CONFIGFS_ATTR(, ratelimit_interval_ms);\n+CONFIGFS_ATTR(, ratelimit_burst);\n \n static struct configfs_attribute *netconsole_target_attrs[] = {\n \t\u0026attr_enabled,\n@@ -1684,6 +1794,8 @@ static struct configfs_attribute *netconsole_target_attrs[] = {\n \t\u0026attr_local_mac,\n \t\u0026attr_remote_mac,\n \t\u0026attr_transmit_errors,\n+\t\u0026attr_ratelimit_interval_ms,\n+\t\u0026attr_ratelimit_burst,\n \tNULL,\n };\n \n@@ -2463,6 +2575,34 @@ static void send_msg_udp(struct netconsole_target *nt, const char *msg,\n \t}\n }\n \n+static void send_ratelimit_notice(struct netconsole_target *nt, bool extended)\n+{\n+\tint len = 0;\n+\tu64 ts_usec;\n+\tu32 drops;\n+\n+\tdrops = netconsole_take_drops(nt);\n+\tif (!drops)\n+\t\treturn;\n+\n+\tif (extended) {\n+\t\t/* append the extended headers */\n+\t\tif (nt-\u003erelease)\n+\t\t\tlen = scnprintf(nt-\u003ebuf, sizeof(nt-\u003ebuf), \"%s,\",\n+\t\t\t\t\tinit_utsname()-\u003erelease);\n+\n+\t\tts_usec = div_u64(local_clock(), NSEC_PER_USEC);\n+\t\tlen += scnprintf(nt-\u003ebuf + len, sizeof(nt-\u003ebuf) - len,\n+\t\t\t\t \"%u,0,%llu,-;\", LOGLEVEL_WARNING, ts_usec);\n+\t}\n+\n+\tlen += scnprintf(nt-\u003ebuf + len, sizeof(nt-\u003ebuf) - len,\n+\t\t\t \"netconsole: %u messages dropped by rate limit\\n\",\n+\t\t\t drops);\n+\n+\tsend_udp(nt, nt-\u003ebuf, len);\n+}\n+\n /**\n * netconsole_write - Generic function to send a msg to all targets\n * @wctxt: nbcon write context\n@@ -2482,6 +2622,9 @@ static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)\n \t\t !netif_running(nt-\u003enp.dev))\n \t\t\tcontinue;\n \n+\t\tif (netconsole_ratelimited(nt))\n+\t\t\tcontinue;\n+\n \t\t/* If nbcon_enter_unsafe() fails, just return given netconsole\n \t\t * lost the ownership, and iterating over the targets will not\n \t\t * be able to re-acquire.\n@@ -2489,6 +2632,8 @@ static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)\n \t\tif (!nbcon_enter_unsafe(wctxt))\n \t\t\treturn;\n \n+\t\tsend_ratelimit_notice(nt, extended);\n+\n \t\tif (extended)\n \t\t\tsend_ext_msg_udp(nt, wctxt);\n \t\telse\ndiff --git a/tools/testing/selftests/drivers/net/netconsole/Makefile b/tools/testing/selftests/drivers/net/netconsole/Makefile\nindex f0674c0017fc4..04cce40f162e9 100644\n--- a/tools/testing/selftests/drivers/net/netconsole/Makefile\n+++ b/tools/testing/selftests/drivers/net/netconsole/Makefile\n@@ -10,6 +10,7 @@ TEST_PROGS := \\\n \tnetcons_cmdline.sh \\\n \tnetcons_fragmented_msg.sh \\\n \tnetcons_overflow.sh \\\n+\tnetcons_ratelimit.sh \\\n \tnetcons_resume.sh \\\n \tnetcons_sysdata.sh \\\n \tnetcons_torture.sh \\\ndiff --git a/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh b/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh\nnew file mode 100755\nindex 0000000000000..38dd1599fe57d\n--- /dev/null\n+++ b/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh\n@@ -0,0 +1,160 @@\n+#!/usr/bin/env bash\n+# SPDX-License-Identifier: GPL-2.0\n+\n+# This test exercises the per-target rate limit. It configures a small burst\n+# over an interval long enough that the bucket is never refilled, sends many\n+# more messages than the burst allows, and checks that the target stops\n+# transmitting once the bucket is empty.\n+#\n+# Clearing the interval has to restore unlimited delivery and tell the\n+# receiver how many messages it missed, which is verified last.\n+#\n+# Author: Breno Leitao \u003cleitao@debian.org\u003e\n+\n+set -euo pipefail\n+\n+SCRIPTDIR=$(dirname \"$(readlink -e \"${BASH_SOURCE[0]}\")\")\n+\n+source \"${SCRIPTDIR}\"/../lib/sh/lib_netcons.sh\n+\n+# Messages sent while the limit is in place, comfortably above BURST so that\n+# the bucket is drained\n+MSG_COUNT=50\n+BURST=5\n+# Long enough that the bucket is not refilled while the test runs\n+INTERVAL_MS=60000\n+# Default the target starts with, as documented in netconsole.rst\n+DEFAULT_BURST=10\n+# What the target sends once it can transmit again\n+DROP_NOTICE=\"messages dropped by rate limit\"\n+\n+# The content of kmsg will be saved to the following file\n+OUTPUT_FILE=\"/tmp/${TARGET}\"\n+\n+function count_msgs() {\n+\tlocal FILE=\"${1}\"\n+\n+\tif [ ! -f \"${FILE}\" ]\n+\tthen\n+\t\techo 0\n+\t\treturn\n+\tfi\n+\n+\t# grep exits 1 on no match, which is a valid result here\n+\tgrep -c \"${MSG}\" \"${FILE}\" || true\n+}\n+\n+function send_msgs() {\n+\tlocal COUNT=\"${1}\"\n+\tlocal I\n+\n+\tfor I in $(seq \"${COUNT}\")\n+\tdo\n+\t\techo \"${MSG}: ${TARGET} ${I}\" \u003e /dev/kmsg\n+\tdone\n+}\n+\n+# A freshly created target has to be unlimited, otherwise every existing\n+# netconsole user would start dropping messages after an upgrade\n+function check_defaults() {\n+\tlocal INTERVAL BURST_DEFAULT\n+\n+\tINTERVAL=$(cat \"${NETCONS_PATH}\"/ratelimit_interval_ms)\n+\tBURST_DEFAULT=$(cat \"${NETCONS_PATH}\"/ratelimit_burst)\n+\n+\tif [ \"${INTERVAL}\" -ne 0 ] ||\n+\t [ \"${BURST_DEFAULT}\" -ne \"${DEFAULT_BURST}\" ]\n+\tthen\n+\t\techo \"FAIL: unexpected rate limit defaults:\" \\\n+\t\t \"interval=${INTERVAL} burst=${BURST_DEFAULT}\" \u003e\u00262\n+\t\texit \"${ksft_fail}\"\n+\tfi\n+}\n+\n+function check_limited() {\n+\tlocal RECEIVED\n+\n+\tRECEIVED=$(count_msgs \"${OUTPUT_FILE}\")\n+\n+\t# Unrelated kernel messages share the bucket, so fewer than BURST of\n+\t# ours can get through, but never more\n+\tif [ \"${RECEIVED}\" -gt \"${BURST}\" ]\n+\tthen\n+\t\techo \"FAIL: received ${RECEIVED} messages with ratelimit_burst=${BURST}\" \u003e\u00262\n+\t\tcat \"${OUTPUT_FILE}\" \u003e\u00262\n+\t\texit \"${ksft_fail}\"\n+\tfi\n+}\n+\n+# The notice below travels ahead of the message that reopened the bucket, so\n+# waiting for the file to appear is not enough\n+function msg_received() {\n+\tgrep -q \"${MSG}\" \"${OUTPUT_FILE}\" 2\u003e /dev/null\n+}\n+\n+# The messages lost above have to be reported to the receiver\n+function check_drops_reported() {\n+\tif ! grep -q \"${DROP_NOTICE}\" \"${OUTPUT_FILE}\"\n+\tthen\n+\t\techo \"FAIL: no rate limit notice in ${OUTPUT_FILE}\" \u003e\u00262\n+\t\tcat \"${OUTPUT_FILE}\" \u003e\u00262\n+\t\texit \"${ksft_fail}\"\n+\tfi\n+}\n+\n+# ========== #\n+# Start here #\n+# ========== #\n+\n+modprobe netdevsim 2\u003e /dev/null || true\n+modprobe netconsole 2\u003e /dev/null || true\n+\n+# Check for basic system dependency and exit if not found\n+check_for_dependencies\n+# Remove the namespace, interfaces and netconsole target on exit\n+trap cleanup EXIT\n+\n+# Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)\n+echo \"6 5\" \u003e /proc/sys/kernel/printk\n+# Create one namespace and two interfaces\n+set_network\n+# Create a dynamic target for netconsole\n+create_dynamic_target\n+\n+check_defaults\n+\n+# Set the burst before the interval, so that no message escapes while the\n+# target still carries the default burst\n+echo \"${BURST}\" \u003e \"${NETCONS_PATH}\"/ratelimit_burst\n+echo \"${INTERVAL_MS}\" \u003e \"${NETCONS_PATH}\"/ratelimit_interval_ms\n+\n+listen_port_and_save_to \"${OUTPUT_FILE}\" \u0026\n+wait_for_port \"${NAMESPACE}\" \"${PORT}\" \"ipv4\"\n+send_msgs \"${MSG_COUNT}\"\n+# This half of the test is about messages that never arrive, so there is\n+# nothing to busywait on\n+sleep 1\n+pkill_socat\n+check_limited\n+rm -f \"${OUTPUT_FILE}\"\n+\n+# Dropping the interval back to zero has to make the target unlimited again\n+echo 0 \u003e \"${NETCONS_PATH}\"/ratelimit_interval_ms\n+\n+listen_port_and_save_to \"${OUTPUT_FILE}\" \u0026\n+wait_for_port \"${NAMESPACE}\" \"${PORT}\" \"ipv4\"\n+send_msgs 1\n+if ! busywait \"${BUSYWAIT_TIMEOUT}\" msg_received\n+then\n+\techo \"FAIL: Timed out waiting (${BUSYWAIT_TIMEOUT} ms) for netconsole\" \\\n+\t \"message in ${OUTPUT_FILE} after clearing the rate limit\" \u003e\u00262\n+\texit \"${ksft_fail}\"\n+fi\n+validate_msg \"${OUTPUT_FILE}\"\n+check_drops_reported\n+pkill_socat\n+rm -f \"${OUTPUT_FILE}\"\n+\n+trap - EXIT\n+cleanup\n+exit \"${ksft_pass}\"\n"
} |
| 2/1 | 2026/08/18 11:16 | agent | patch-evaluator |
1mModel:best-expensive Args: null Results: {
"EnableConfigs": [
"NETCONSOLE",
"NETCONSOLE_DYNAMIC",
"CONFIGFS_FS"
],
"FocusSymbols": [
"ratelimit_interval_ms_store",
"ratelimit_burst_store",
"ratelimit_interval_ms_show",
"ratelimit_burst_show"
],
"Reasoning": "The patch introduces rate limiting for netconsole targets to prevent a host from saturating the receiving agent with continuous logs. It adds new configfs attributes `ratelimit_interval_ms` and `ratelimit_burst` to configure the rate limit per target. The rate limiting logic is implemented in the console write path using `ratelimit_state`. The changes are reachable via configfs and the printk console write path. The configfs store/show functions are good candidates for fuzzing. The feature requires `CONFIG_NETCONSOLE`, `CONFIG_NETCONSOLE_DYNAMIC`, and `CONFIG_CONFIGFS_FS`.",
"WorthFuzzing": true
}Instruction: You are an expert Linux kernel maintainer. Your job is to review a provided patch series and determine if it makes functional changes to the kernel that should be fuzzed. IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively use your code access tools to examine the actual source code and confirm any assumptions. Return WorthFuzzing=false if the patch only contains: - Modifications to Documentation/, Kconfig files, or code comments. - Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints. - Changes to numeric constants or macros that do not functionally alter execution flow. - Code paths that are impossible to reach in virtualized environments like GCE or QEMU, even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim). - Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed, ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU. - Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove) that are executed only during PCI hot-unplug or sysfs driver unbind operations. If it modifies reachable core kernel logic, drivers, or architectures, use your code search tools to verify the code can be executed, then return WorthFuzzing=true. When returning WorthFuzzing=true, you MUST ALSO: 1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols. Avoid listing generic hot-path functions to prevent skewed test distributions. Prefer non-static, non-inlined API entrypoint functions over internal static helper functions (which are inlined by the compiler and do not have distinct symbol addresses). 2. Identify any specific CONFIG_ options required to properly test this new/modified feature. Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions. Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs output array, and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4"). Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: For your convenience, here is the diff of the changes:
commit 4906d8bd1febf63967491596728581965fa8da17
Author: syz-cluster <triage@syzkaller.com>
Date: Tue Aug 18 11:16:14 2026 +0000
syz-cluster: applied patch under review
diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst
index 4ab5d7b05cf10..7369cd89ae76c 100644
--- a/Documentation/networking/netconsole.rst
+++ b/Documentation/networking/netconsole.rst
@@ -177,6 +177,49 @@ You can modify these targets in runtime by creating the following targets::
cat cmdline1/remote_ip
10.0.0.3
+Rate limiting
+-------------
+
+Netconsole hands every console message to every enabled target, so a host that
+logs continuously can saturate the receiving agent. Each target carries a token
+bucket that drops messages once the configured rate is exceeded, controlled by
+two files in the target directory:
+
+ ===================== ================================================
+ ratelimit_interval_ms Length of the accounting interval, in
+ milliseconds. Zero, the default, sends
+ everything.
+ ratelimit_burst Messages allowed per interval. Defaults to
+ 10; zero drops every message.
+ ===================== ================================================
+
+Unlike most target parameters, both knobs can be written while the target is
+enabled, which is when a flooding target most likely needs them.
+
+The limit is applied per message, not per packet, so a message big enough to be
+split into several `ncfrag` packets is either sent whole or not at all.
+
+Crash output bypasses the bucket. While an oops, BUG() or panic() is in
+progress every message is sent, whatever the limit says, so a small burst
+cannot cost you part of a crash dump.
+
+A drop leaves nothing on the wire, so the receiver is told what it missed as
+soon as a message gets through again::
+
+ netconsole: 45 messages dropped by rate limit
+
+The notice only travels with the next message the bucket allows. A host that
+goes quiet right after being limited reports the drops later, when it logs
+again, and a target with a `ratelimit_burst` of zero never reports them.
+
+netconsole generates the notice itself instead of logging it, so on an
+extended target the record carries a sequence number of zero.
+
+Capping a target at 500 messages a minute::
+
+ echo 60000 > ratelimit_interval_ms
+ echo 500 > ratelimit_burst
+
Append User Data
----------------
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index b358e5c367351..0af2e5b4335c0 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -49,6 +49,8 @@
#include <linux/rtnetlink.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/clock.h>
MODULE_AUTHOR("Matt Mackall <mpm@selenic.com>");
MODULE_DESCRIPTION("Console driver for network interfaces");
@@ -175,6 +177,8 @@ struct netcons_userdata {
* @sysdata: Cached, formatted string of append
* @sysdata_fields: Sysdata features enabled.
* @msgcounter: Message sent counter.
+ * @ratelimit: Opaque structure to ratelimit messages
+ * @pending_drops: Messages dropped since the last notice was sent.
* @stats: Packet send stats for the target. Used for debugging.
* @state: State of the target.
* Visible from userspace (read-write).
@@ -219,6 +223,8 @@ struct netconsole_target {
u32 sysdata_fields;
/* protected by target_list_lock */
u32 msgcounter;
+ u32 pending_drops;
+ struct ratelimit_state ratelimit;
#endif
struct netconsole_target_stats stats;
enum target_state state;
@@ -282,6 +288,34 @@ static void dynamic_netconsole_mutex_unlock(void)
mutex_unlock(&dynamic_netconsole_mutex);
}
+static void netconsole_ratelimit_init(struct netconsole_target *nt)
+{
+ ratelimit_state_init(&nt->ratelimit, 0, DEFAULT_RATELIMIT_BURST);
+ ratelimit_set_flags(&nt->ratelimit, RATELIMIT_MSG_ON_RELEASE);
+}
+
+static bool netconsole_ratelimited(struct netconsole_target *nt)
+{
+ /* A limit meant for steady-state logging must not eat a crash dump. */
+ if (oops_in_progress)
+ return false;
+
+ if (__ratelimit(&nt->ratelimit))
+ return false;
+
+ nt->pending_drops++;
+
+ return true;
+}
+
+static u32 netconsole_take_drops(struct netconsole_target *nt)
+{
+ u32 drops = nt->pending_drops;
+
+ nt->pending_drops = 0;
+ return drops;
+}
+
#else /* !CONFIG_NETCONSOLE_DYNAMIC */
static int __init dynamic_netconsole_init(void)
@@ -318,6 +352,20 @@ static void dynamic_netconsole_mutex_unlock(void)
{
}
+static void netconsole_ratelimit_init(struct netconsole_target *nt)
+{
+}
+
+static bool netconsole_ratelimited(struct netconsole_target *nt)
+{
+ return false;
+}
+
+static u32 netconsole_take_drops(struct netconsole_target *nt)
+{
+ return 0;
+}
+
#endif /* CONFIG_NETCONSOLE_DYNAMIC */
/* Check if the target was bound by mac address. */
@@ -686,6 +734,7 @@ static struct netconsole_target *alloc_and_init(void)
nt->remote_port = 6666;
eth_broadcast_addr(nt->remote_mac);
nt->state = STATE_DISABLED;
+ netconsole_ratelimit_init(nt);
INIT_WORK(&nt->resume_wq, process_resume_target);
/* Set up the skb pool primitives once; enabling only refills it. */
skb_queue_head_init(&nt->skb_pool);
@@ -912,6 +961,21 @@ static ssize_t transmit_errors_show(struct config_item *item, char *buf)
return sysfs_emit(buf, "%llu\n", xmit_drop_count + enomem_count);
}
+static ssize_t ratelimit_interval_ms_show(struct config_item *item, char *buf)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ return sysfs_emit(buf, "%u\n",
+ jiffies_to_msecs(READ_ONCE(nt->ratelimit.interval)));
+}
+
+static ssize_t ratelimit_burst_show(struct config_item *item, char *buf)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ return sysfs_emit(buf, "%d\n", READ_ONCE(nt->ratelimit.burst));
+}
+
/* configfs helper to display if cpu_nr sysdata feature is enabled */
static ssize_t sysdata_cpu_nr_enabled_show(struct config_item *item, char *buf)
{
@@ -1307,6 +1371,50 @@ static ssize_t remote_mac_store(struct config_item *item, const char *buf,
return ret;
}
+static ssize_t ratelimit_interval_ms_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ unsigned int interval;
+ unsigned long jifs;
+ ssize_t ret;
+
+ ret = kstrtouint(buf, 10, &interval);
+ if (ret)
+ return ret;
+
+ jifs = msecs_to_jiffies(interval);
+ if (jifs > INT_MAX)
+ return -ERANGE;
+
+ dynamic_netconsole_mutex_lock();
+ WRITE_ONCE(nt->ratelimit.interval, jifs);
+ dynamic_netconsole_mutex_unlock();
+
+ return count;
+}
+
+static ssize_t ratelimit_burst_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ unsigned int burst;
+ ssize_t ret;
+
+ ret = kstrtouint(buf, 10, &burst);
+ if (ret)
+ return ret;
+
+ if (burst > INT_MAX)
+ return -ERANGE;
+
+ dynamic_netconsole_mutex_lock();
+ WRITE_ONCE(nt->ratelimit.burst, burst);
+ dynamic_netconsole_mutex_unlock();
+
+ return count;
+}
+
struct userdatum {
struct config_item item;
char value[MAX_EXTRADATA_VALUE_LEN];
@@ -1671,6 +1779,8 @@ CONFIGFS_ATTR_RO(, local_mac);
CONFIGFS_ATTR(, remote_mac);
CONFIGFS_ATTR(, release);
CONFIGFS_ATTR_RO(, transmit_errors);
+CONFIGFS_ATTR(, ratelimit_interval_ms);
+CONFIGFS_ATTR(, ratelimit_burst);
static struct configfs_attribute *netconsole_target_attrs[] = {
&attr_enabled,
@@ -1684,6 +1794,8 @@ static struct configfs_attribute *netconsole_target_attrs[] = {
&attr_local_mac,
&attr_remote_mac,
&attr_transmit_errors,
+ &attr_ratelimit_interval_ms,
+ &attr_ratelimit_burst,
NULL,
};
@@ -2463,6 +2575,34 @@ static void send_msg_udp(struct netconsole_target *nt, const char *msg,
}
}
+static void send_ratelimit_notice(struct netconsole_target *nt, bool extended)
+{
+ int len = 0;
+ u64 ts_usec;
+ u32 drops;
+
+ drops = netconsole_take_drops(nt);
+ if (!drops)
+ return;
+
+ if (extended) {
+ /* append the extended headers */
+ if (nt->release)
+ len = scnprintf(nt->buf, sizeof(nt->buf), "%s,",
+ init_utsname()->release);
+
+ ts_usec = div_u64(local_clock(), NSEC_PER_USEC);
+ len += scnprintf(nt->buf + len, sizeof(nt->buf) - len,
+ "%u,0,%llu,-;", LOGLEVEL_WARNING, ts_usec);
+ }
+
+ len += scnprintf(nt->buf + len, sizeof(nt->buf) - len,
+ "netconsole: %u messages dropped by rate limit\n",
+ drops);
+
+ send_udp(nt, nt->buf, len);
+}
+
/**
* netconsole_write - Generic function to send a msg to all targets
* @wctxt: nbcon write context
@@ -2482,6 +2622,9 @@ static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)
!netif_running(nt->np.dev))
continue;
+ if (netconsole_ratelimited(nt))
+ continue;
+
/* If nbcon_enter_unsafe() fails, just return given netconsole
* lost the ownership, and iterating over the targets will not
* be able to re-acquire.
@@ -2489,6 +2632,8 @@ static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)
if (!nbcon_enter_unsafe(wctxt))
return;
+ send_ratelimit_notice(nt, extended);
+
if (extended)
send_ext_msg_udp(nt, wctxt);
else
diff --git a/tools/testing/selftests/drivers/net/netconsole/Makefile b/tools/testing/selftests/drivers/net/netconsole/Makefile
index f0674c0017fc4..04cce40f162e9 100644
--- a/tools/testing/selftests/drivers/net/netconsole/Makefile
+++ b/tools/testing/selftests/drivers/net/netconsole/Makefile
@@ -10,6 +10,7 @@ TEST_PROGS := \
netcons_cmdline.sh \
netcons_fragmented_msg.sh \
netcons_overflow.sh \
+ netcons_ratelimit.sh \
netcons_resume.sh \
netcons_sysdata.sh \
netcons_torture.sh \
diff --git a/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh b/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh
new file mode 100755
index 0000000000000..38dd1599fe57d
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh
@@ -0,0 +1,160 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This test exercises the per-target rate limit. It configures a small burst
+# over an interval long enough that the bucket is never refilled, sends many
+# more messages than the burst allows, and checks that the target stops
+# transmitting once the bucket is empty.
+#
+# Clearing the interval has to restore unlimited delivery and tell the
+# receiver how many messages it missed, which is verified last.
+#
+# Author: Breno Leitao <leitao@debian.org>
+
+set -euo pipefail
+
+SCRIPTDIR=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")
+
+source "${SCRIPTDIR}"/../lib/sh/lib_netcons.sh
+
+# Messages sent while the limit is in place, comfortably above BURST so that
+# the bucket is drained
+MSG_COUNT=50
+BURST=5
+# Long enough that the bucket is not refilled while the test runs
+INTERVAL_MS=60000
+# Default the target starts with, as documented in netconsole.rst
+DEFAULT_BURST=10
+# What the target sends once it can transmit again
+DROP_NOTICE="messages dropped by rate limit"
+
+# The content of kmsg will be saved to the following file
+OUTPUT_FILE="/tmp/${TARGET}"
+
+function count_msgs() {
+ local FILE="${1}"
+
+ if [ ! -f "${FILE}" ]
+ then
+ echo 0
+ return
+ fi
+
+ # grep exits 1 on no match, which is a valid result here
+ grep -c "${MSG}" "${FILE}" || true
+}
+
+function send_msgs() {
+ local COUNT="${1}"
+ local I
+
+ for I in $(seq "${COUNT}")
+ do
+ echo "${MSG}: ${TARGET} ${I}" > /dev/kmsg
+ done
+}
+
+# A freshly created target has to be unlimited, otherwise every existing
+# netconsole user would start dropping messages after an upgrade
+function check_defaults() {
+ local INTERVAL BURST_DEFAULT
+
+ INTERVAL=$(cat "${NETCONS_PATH}"/ratelimit_interval_ms)
+ BURST_DEFAULT=$(cat "${NETCONS_PATH}"/ratelimit_burst)
+
+ if [ "${INTERVAL}" -ne 0 ] ||
+ [ "${BURST_DEFAULT}" -ne "${DEFAULT_BURST}" ]
+ then
+ echo "FAIL: unexpected rate limit defaults:" \
+ "interval=${INTERVAL} burst=${BURST_DEFAULT}" >&2
+ exit "${ksft_fail}"
+ fi
+}
+
+function check_limited() {
+ local RECEIVED
+
+ RECEIVED=$(count_msgs "${OUTPUT_FILE}")
+
+ # Unrelated kernel messages share the bucket, so fewer than BURST of
+ # ours can get through, but never more
+ if [ "${RECEIVED}" -gt "${BURST}" ]
+ then
+ echo "FAIL: received ${RECEIVED} messages with ratelimit_burst=${BURST}" >&2
+ cat "${OUTPUT_FILE}" >&2
+ exit "${ksft_fail}"
+ fi
+}
+
+# The notice below travels ahead of the message that reopened the bucket, so
+# waiting for the file to appear is not enough
+function msg_received() {
+ grep -q "${MSG}" "${OUTPUT_FILE}" 2> /dev/null
+}
+
+# The messages lost above have to be reported to the receiver
+function check_drops_reported() {
+ if ! grep -q "${DROP_NOTICE}" "${OUTPUT_FILE}"
+ then
+ echo "FAIL: no rate limit notice in ${OUTPUT_FILE}" >&2
+ cat "${OUTPUT_FILE}" >&2
+ exit "${ksft_fail}"
+ fi
+}
+
+# ========== #
+# Start here #
+# ========== #
+
+modprobe netdevsim 2> /dev/null || true
+modprobe netconsole 2> /dev/null || true
+
+# Check for basic system dependency and exit if not found
+check_for_dependencies
+# Remove the namespace, interfaces and netconsole target on exit
+trap cleanup EXIT
+
+# Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)
+echo "6 5" > /proc/sys/kernel/printk
+# Create one namespace and two interfaces
+set_network
+# Create a dynamic target for netconsole
+create_dynamic_target
+
+check_defaults
+
+# Set the burst before the interval, so that no message escapes while the
+# target still carries the default burst
+echo "${BURST}" > "${NETCONS_PATH}"/ratelimit_burst
+echo "${INTERVAL_MS}" > "${NETCONS_PATH}"/ratelimit_interval_ms
+
+listen_port_and_save_to "${OUTPUT_FILE}" &
+wait_for_port "${NAMESPACE}" "${PORT}" "ipv4"
+send_msgs "${MSG_COUNT}"
+# This half of the test is about messages that never arrive, so there is
+# nothing to busywait on
+sleep 1
+pkill_socat
+check_limited
+rm -f "${OUTPUT_FILE}"
+
+# Dropping the interval back to zero has to make the target unlimited again
+echo 0 > "${NETCONS_PATH}"/ratelimit_interval_ms
+
+listen_port_and_save_to "${OUTPUT_FILE}" &
+wait_for_port "${NAMESPACE}" "${PORT}" "ipv4"
+send_msgs 1
+if ! busywait "${BUSYWAIT_TIMEOUT}" msg_received
+then
+ echo "FAIL: Timed out waiting (${BUSYWAIT_TIMEOUT} ms) for netconsole" \
+ "message in ${OUTPUT_FILE} after clearing the rate limit" >&2
+ exit "${ksft_fail}"
+fi
+validate_msg "${OUTPUT_FILE}"
+check_drops_reported
+pkill_socat
+rm -f "${OUTPUT_FILE}"
+
+trap - EXIT
+cleanup
+exit "${ksft_pass}"
|
| 3/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 6829 output: 34 thoughts: 156 Thoughts: **My Analysis of the Netconsole Rate Limiting Patch** Okay, so I'm looking at this patch that introduces rate limiting to netconsole. It seems straightforward enough; it's touching `drivers/net/netconsole.c`, which is the expected place. They're adding `ratelimit_interval_ms` and `ratelimit_burst` as configfs attributes, which is a sensible approach for controlling the rate limiting parameters. I see they're using `ratelimit_state` and `__ratelimit`, which suggests they are using the existing kernel ratelimit infrastructure effectively. Plus, a notification for dropped messages? Good, that's crucial for observability. Now, let's just make sure the crucial bits are actually reachable. I need to quickly check the configuration dependencies. Right, it's inside the `CONFIG_NETCONSOLE_DYNAMIC` block. Wait, I'm just quickly confirming... yes, `netconsole_ratelimit_init` *is* also defined within that same `#ifdef CONFIG_NETCONSOLE_DYNAMIC` block. Okay, all looks good so far. I'll need to verify that those configurations are properly set in our setup, but on the surface, this looks well-scoped and implemented with the appropriate dependencies. |
| 4/2 | 2026/08/18 11:16 | tool | grepper |
0mArgs:{
"Expression": "CONFIG_NETCONSOLE_DYNAMIC",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=214=struct netconsole_target {\ndrivers/net/netconsole.c-215-\tstruct list_head\tlist;\ndrivers/net/netconsole.c:216:#ifdef\tCONFIG_NETCONSOLE_DYNAMIC\ndrivers/net/netconsole.c-217-\tstruct config_group\tgroup;\n--\ndrivers/net/netconsole.c-246-\ndrivers/net/netconsole.c:247:#ifdef\tCONFIG_NETCONSOLE_DYNAMIC\ndrivers/net/netconsole.c-248-\n--\ndrivers/net/netconsole.c=311=static u32 netconsole_take_drops(struct netconsole_target *nt)\n--\ndrivers/net/netconsole.c-318-\ndrivers/net/netconsole.c:319:#else\t/* !CONFIG_NETCONSOLE_DYNAMIC */\ndrivers/net/netconsole.c-320-\n--\ndrivers/net/netconsole.c=364=static u32 netconsole_take_drops(struct netconsole_target *nt)\n--\ndrivers/net/netconsole.c-368-\ndrivers/net/netconsole.c:369:#endif\t/* CONFIG_NETCONSOLE_DYNAMIC */\ndrivers/net/netconsole.c-370-\n--\ndrivers/net/netconsole.c=796=static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)\n--\ndrivers/net/netconsole.c-819-\ndrivers/net/netconsole.c:820:#ifdef\tCONFIG_NETCONSOLE_DYNAMIC\ndrivers/net/netconsole.c-821-\n--\ndrivers/net/netconsole.c=2006=static int prepare_sysdata(struct netconsole_target *nt,\n--\ndrivers/net/netconsole.c-2028-}\ndrivers/net/netconsole.c:2029:#endif\t/* CONFIG_NETCONSOLE_DYNAMIC */\ndrivers/net/netconsole.c-2030-\n--\ndrivers/net/netconsole.c=2286=static int netpoll_send_udp(struct netconsole_target *nt, const char *msg,\n--\ndrivers/net/netconsole.c-2330- * occurred it increments statistics in nt-\u003estats accordingly.\ndrivers/net/netconsole.c:2331: * Only calls netpoll_send_udp if CONFIG_NETCONSOLE_DYNAMIC is disabled.\ndrivers/net/netconsole.c-2332- */\ndrivers/net/netconsole.c=2333=static void send_udp(struct netconsole_target *nt, const char *msg, int len)\n--\ndrivers/net/netconsole.c-2336-\ndrivers/net/netconsole.c:2337:\tif (IS_ENABLED(CONFIG_NETCONSOLE_DYNAMIC)) {\ndrivers/net/netconsole.c-2338-\t\tif (result == NET_XMIT_DROP) {\n--\ndrivers/net/netconsole.c=2350=static void send_msg_no_fragmentation(struct netconsole_target *nt,\n--\ndrivers/net/netconsole.c-2358-\ndrivers/net/netconsole.c:2359:#ifdef CONFIG_NETCONSOLE_DYNAMIC\ndrivers/net/netconsole.c-2360-\tsysdata = nt-\u003esysdata;\n--\ndrivers/net/netconsole.c=2394=static void send_fragmented_body(struct netconsole_target *nt,\n--\ndrivers/net/netconsole.c-2406-\ndrivers/net/netconsole.c:2407:#ifdef CONFIG_NETCONSOLE_DYNAMIC\ndrivers/net/netconsole.c-2408-\tsysdata_ptr = nt-\u003esysdata;\n--\ndrivers/net/netconsole.c=2532=static void send_ext_msg_udp(struct netconsole_target *nt,\n--\ndrivers/net/netconsole.c-2543-\ndrivers/net/netconsole.c:2544:#ifdef CONFIG_NETCONSOLE_DYNAMIC\ndrivers/net/netconsole.c-2545-\tsysdata_len = prepare_sysdata(nt, wctxt);\n--\ndrivers/net/netconsole.c=2768=static struct netconsole_target *alloc_param_target(char *target_config,\n--\ndrivers/net/netconsole.c-2811-\t\tnetconsole_skb_pool_flush(nt);\ndrivers/net/netconsole.c:2812:\t\tif (!IS_ENABLED(CONFIG_NETCONSOLE_DYNAMIC))\ndrivers/net/netconsole.c-2813-\t\t\t/* only fail if dynamic reconfiguration is set,\n--\ndrivers/net/netconsole.c=2830=static void free_param_target(struct netconsole_target *nt)\n--\ndrivers/net/netconsole.c-2835-\tnetpoll_cleanup(\u0026nt-\u003enp);\ndrivers/net/netconsole.c:2836:#ifdef\tCONFIG_NETCONSOLE_DYNAMIC\ndrivers/net/netconsole.c-2837-\tkfree(rcu_access_pointer(nt-\u003euserdata));\n--\ndrivers/net/netconsole.c=2860=static int __init init_netconsole(void)\n--\ndrivers/net/netconsole.c-2873-\t\t\tif (IS_ERR(nt)) {\ndrivers/net/netconsole.c:2874:\t\t\t\tif (IS_ENABLED(CONFIG_NETCONSOLE_DYNAMIC))\ndrivers/net/netconsole.c-2875-\t\t\t\t\tcontinue;\n"
} |
| 5/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 8664 output: 37 thoughts: 90 Thoughts: Okay, let's break this down. **Investigating Netconsole Rate Limiting Configuration** Right, so the rate limiting for Netconsole is handled within `drivers/net/netconsole.c`. My initial focus is on understanding how this rate limiting is configured and controlled. The clue is that I see mention of `ratelimit_interval_ms_store` and `ratelimit_burst_store`. Those sound like configfs attributes, and that's usually a good indicator of dynamic configuration. The kernel often uses configfs for sysfs-like interfaces that can be modified at runtime. I also remember that these attributes are only available if `CONFIG_NETCONSOLE_DYNAMIC` is enabled. Makes sense – dynamic configuration is usually a separate feature. So, the next logical step is to dive right into `drivers/net/netconsole.c`. I need to examine the implementation of `ratelimit_interval_ms_store` to see the mechanisms used to control the limiting behavior. I'm looking for the details on where the relevant data structures reside and how these attribute values impact the rate limiting logic within the netconsole driver itself. I'm expecting some kind of timer or counter-based implementation, but I want to see the specifics. |
| 6/2 | 2026/08/18 11:16 | tool | grepper |
0mArgs:{
"Expression": "ratelimit_interval_ms_store",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=1348=static ssize_t remote_mac_store(struct config_item *item, const char *buf,\n--\ndrivers/net/netconsole.c-1373-\ndrivers/net/netconsole.c:1374:static ssize_t ratelimit_interval_ms_store(struct config_item *item,\ndrivers/net/netconsole.c-1375-\t\t\t\t\t const char *buf, size_t count)\n"
} |
| 7/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 9183 output: 35 thoughts: 24 Thoughts: Here's my thought process, summarized as you requested: **Investigating Network Console Rate Limiting** Okay, so I need to understand the rate limiting behavior in the network console. The likely place to start looking for that is in the core driver file: `drivers/net/netconsole.c`. Specifically, I'm expecting to find the key pieces related to rate limiting within the function or functions that handle the configuration or storage of burst limits. My target is `ratelimit_burst_store`. That name is pretty self-explanatory, so it should lead me right to the relevant code. |
| 8/2 | 2026/08/18 11:16 | tool | grepper |
0mArgs:{
"Expression": "ratelimit_burst_store",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=1374=static ssize_t ratelimit_interval_ms_store(struct config_item *item,\n--\ndrivers/net/netconsole.c-1396-\ndrivers/net/netconsole.c:1397:static ssize_t ratelimit_burst_store(struct config_item *item, const char *buf,\ndrivers/net/netconsole.c-1398-\t\t\t\t size_t count)\n"
} |
| 9/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 9494 output: 34 thoughts: 23 Thoughts: Here's a summary of my thought process, as requested: **Diving into Netconsole Ratelimiting** Okay, so I need to understand how the network console handles rate limiting. That's a critical piece of the puzzle, especially in situations where flooding might be an issue. My first instinct is to dive into the source code, specifically `drivers/net/netconsole.c`. That's where I'd expect to find the core implementation. I'm going to look for the `netconsole_ratelimited` function, assuming it exists. This is a common naming convention, and it's likely to be the entry point or central function related to rate limiting within the netconsole module. From there, I can analyze the logic, understand the algorithm they use, and see how they're handling potentially overwhelming network traffic. I will then cross reference other areas of the code base that are relevant. |
| 10/2 | 2026/08/18 11:16 | tool | grepper |
0mArgs:{
"Expression": "netconsole_ratelimited",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=291=static void netconsole_ratelimit_init(struct netconsole_target *nt)\n--\ndrivers/net/netconsole.c-296-\ndrivers/net/netconsole.c:297:static bool netconsole_ratelimited(struct netconsole_target *nt)\ndrivers/net/netconsole.c-298-{\n--\ndrivers/net/netconsole.c=355=static void netconsole_ratelimit_init(struct netconsole_target *nt)\n--\ndrivers/net/netconsole.c-358-\ndrivers/net/netconsole.c:359:static bool netconsole_ratelimited(struct netconsole_target *nt)\ndrivers/net/netconsole.c-360-{\n--\ndrivers/net/netconsole.c=2613=static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)\n--\ndrivers/net/netconsole.c-2624-\ndrivers/net/netconsole.c:2625:\t\tif (netconsole_ratelimited(nt))\ndrivers/net/netconsole.c-2626-\t\t\tcontinue;\n"
} |
| 11/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 10044 output: 36 thoughts: 383 Thoughts: **Analyzing the Reachability of the New Rate Limiting Feature** Okay, so this feature looks definitely reachable. It's adding `ratelimit_interval_ms_store` and `ratelimit_burst_store`, which are configfs attributes. My immediate focus needs to be on these functions, along with their counterpart `show` functions: `ratelimit_interval_ms_show` and `ratelimit_burst_show`. And, of course, the key limiting functions, `netconsole_ratelimited` and `send_ratelimit_notice`. Now, let me just double-check, is `ratelimit_interval_ms_store` static? Yep, it is. Hmm, wait a second... configfs `store` and `show` functions are *usually* static because they are called through function pointers in the `configfs_attribute` structure. But the prompt is asking to prefer non-static API entrypoints. Are there any *non*-static functions in this patch? Let me review the functions added by this patch to see which have distinct symbol addresses. Okay, going through the list, it's: * `netconsole_ratelimit_init` (static) * `netconsole_ratelimited` (static) * `netconsole_take_drops` (static) * `ratelimit_interval_ms_show` (static) * `ratelimit_burst_show` (static) * `ratelimit_interval_ms_store` (static) * `ratelimit_burst_store` (static) * `send_ratelimit_notice` (static) Damn! They're *all* static. That means I should probably focus on those configfs attribute functions as they are used in a unique way to the static helper functions. I should also check the main write function, `netconsole_write`. But hold on, the prompt *specifically* wants me to prefer non-static. The prompt says "Prefer non-static, non-inlined API entrypoint functions over internal static helper functions". But I have to remember that configfs store/show functions are *not* inlined. They are not inlined because their addresses are taken and put into struct configfs_attribute. So it's still good. I should check how they are used. |
| 12/2 | 2026/08/18 11:16 | tool | grepper |
0mArgs:{
"Expression": "CONFIGFS_ATTR.*ratelimit",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=1781=CONFIGFS_ATTR_RO(, transmit_errors);\ndrivers/net/netconsole.c:1782:CONFIGFS_ATTR(, ratelimit_interval_ms);\ndrivers/net/netconsole.c:1783:CONFIGFS_ATTR(, ratelimit_burst);\ndrivers/net/netconsole.c-1784-\n"
} |
| 13/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 11084 output: 32 thoughts: 214 Thoughts: **Analyzing the netconsole Rate Limiting Implementation** Okay, so I'm looking at how rate limiting is handled in the `netconsole` code, specifically how `CONFIGFS_ATTR` is used. My initial understanding was that this macro somehow inlined or directly used functions like `ratelimit_interval_ms_store` and `ratelimit_interval_ms_show`. However, upon closer inspection, it looks like `CONFIGFS_ATTR` generates a `struct configfs_attribute` named `attr_ratelimit_interval_ms`, and these functions are actually *passed* to this generated structure. That makes more sense. The macro needs `name_store` and `name_show` to exist, which are effectively the function pointers. This means `ratelimit_interval_ms_store` and `ratelimit_burst_store` aren't being inlined, as I initially assumed. This also means we can, and should, include them in `FocusSymbols`. Now, moving upstream, the main entry point for writing messages appears to be `netconsole_write`. This function, I believe, calls into the rate limiting logic, namely `netconsole_ratelimited` and `send_ratelimit_notice`. I need to verify that `netconsole_write` is not static. That is important. |
| 14/2 | 2026/08/18 11:16 | tool | grepper |
0mArgs:{
"Expression": "netconsole_write",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=2578=static void send_ratelimit_notice(struct netconsole_target *nt, bool extended)\n--\ndrivers/net/netconsole.c-2606-/**\ndrivers/net/netconsole.c:2607: * netconsole_write - Generic function to send a msg to all targets\ndrivers/net/netconsole.c-2608- * @wctxt: nbcon write context\n--\ndrivers/net/netconsole.c-2612- */\ndrivers/net/netconsole.c:2613:static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)\ndrivers/net/netconsole.c-2614-{\n--\ndrivers/net/netconsole.c-2645-\ndrivers/net/netconsole.c:2646:static void netconsole_write_ext(struct console *con __always_unused,\ndrivers/net/netconsole.c-2647-\t\t\t\t struct nbcon_write_context *wctxt)\ndrivers/net/netconsole.c-2648-{\ndrivers/net/netconsole.c:2649:\tnetconsole_write(wctxt, true);\ndrivers/net/netconsole.c-2650-}\ndrivers/net/netconsole.c-2651-\ndrivers/net/netconsole.c:2652:static void netconsole_write_basic(struct console *con __always_unused,\ndrivers/net/netconsole.c-2653-\t\t\t\t struct nbcon_write_context *wctxt)\ndrivers/net/netconsole.c-2654-{\ndrivers/net/netconsole.c:2655:\tnetconsole_write(wctxt, false);\ndrivers/net/netconsole.c-2656-}\n--\ndrivers/net/netconsole.c=2842=static struct console netconsole_ext = {\n--\ndrivers/net/netconsole.c-2844-\t.flags = CON_ENABLED | CON_EXTENDED | CON_NBCON | CON_NBCON_ATOMIC_UNSAFE,\ndrivers/net/netconsole.c:2845:\t.write_thread = netconsole_write_ext,\ndrivers/net/netconsole.c:2846:\t.write_atomic = netconsole_write_ext,\ndrivers/net/netconsole.c-2847-\t.device_lock = netconsole_device_lock,\n--\ndrivers/net/netconsole.c=2851=static struct console netconsole = {\n--\ndrivers/net/netconsole.c-2853-\t.flags = CON_ENABLED | CON_NBCON | CON_NBCON_ATOMIC_UNSAFE,\ndrivers/net/netconsole.c:2854:\t.write_thread = netconsole_write_basic,\ndrivers/net/netconsole.c:2855:\t.write_atomic = netconsole_write_basic,\ndrivers/net/netconsole.c-2856-\t.device_lock = netconsole_device_lock,\n"
} |
| 15/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 12374 output: 29 thoughts: 162 Thoughts: **My Netconsole Implementation Plan** Okay, so I'm digging into this `netconsole` implementation. It seems like the core write function, `netconsole_write`, is actually static. That's interesting. I was initially thinking the non-static entry points were `netconsole_write_ext` and `netconsole_write_basic`, but those are also static, too. It makes sense now - they're called through function pointers within that `struct console`. Alright, that clears that up. So, I think I can include `ratelimit_interval_ms_store`, `ratelimit_burst_store`, `ratelimit_interval_ms_show`, `ratelimit_burst_show`, `netconsole_write_ext`, and `netconsole_write_basic` in the new plan. Hold on a second, though. Before I get too far down this road, I need to verify something critical: what are the *actual* configuration options I'll need to work with? I know there's `CONFIG_NETCONSOLE`, and I think there's a `CONFIG_NETCONSOLE_DYNAMIC` as well. But I need to confirm those are the correct names. Best to check `drivers/net/Kconfig` to be absolutely sure. Let's head there and verify these are the configuration options I need to account for. |
| 16/2 | 2026/08/18 11:16 | tool | grepper |
0mArgs:{
"Expression": "config NETCONSOLE",
"PathPrefix": "drivers/net/Kconfig"
}Results: {
"Output": "drivers/net/Kconfig=318=config MACSEC\n--\ndrivers/net/Kconfig-326-\ndrivers/net/Kconfig:327:config NETCONSOLE\ndrivers/net/Kconfig-328-\ttristate \"Network console logging support\"\n--\ndrivers/net/Kconfig-333-\ndrivers/net/Kconfig:334:config NETCONSOLE_DYNAMIC\ndrivers/net/Kconfig-335-\tbool \"Dynamic reconfiguration of logging targets\"\n--\ndrivers/net/Kconfig-344-\ndrivers/net/Kconfig:345:config NETCONSOLE_EXTENDED_LOG\ndrivers/net/Kconfig-346-\tbool \"Set kernel extended message by default\"\n--\ndrivers/net/Kconfig-354-\ndrivers/net/Kconfig:355:config NETCONSOLE_PREPEND_RELEASE\ndrivers/net/Kconfig-356-\tbool \"Prepend kernel release version in the message by default\"\n"
} |
| 17/2 | 2026/08/18 11:16 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 13104 output: 34 thoughts: 18 Thoughts: Here's my thought process, as if I were considering those dependencies: **Dependency Deep Dive** Okay, so I need to get a handle on `NETCONSOLE` and `NETCONSOLE_DYNAMIC` – important options in network configuration, I presume. My first instinct, as always, is to map out the dependency graph. I need to understand what other kernel options, hardware, or libraries are contingent on these being enabled, and, conversely, what these depend on. Are we talking about a simple module, or are there wider implications for the system's network stack? I'll start by checking the Kconfig files. I'll need to locate the definitions for `NETCONSOLE` and `NETCONSOLE_DYNAMIC`, and meticulously examine the `depends on`, `select`, and `default` statements associated with each. That will immediately tell me if enabling one automatically enables, or implies, the other, or if there's any conflict. I'm looking for direct and indirect relationships. Are we talking about specific network drivers, core networking modules, or potentially things like logging frameworks? Furthermore, I should investigate if there's any architecture-specific behavior here. Does the dependency tree change depending on the CPU architecture, the board, or the chosen networking hardware? I'll also want to review any associated documentation or comments within the Kconfig files that might shed light on their purpose or recommended configuration. I'm particularly interested in any warnings or notes about potential conflicts with other features, such as firewalls, routing protocols, or even power management. Ultimately, I need a concise and complete understanding of these dependencies to ensure that the network configuration is as it should be, without conflicts or unintended consequences. This isn't just about enabling these options; it's about making informed choices that align with the specific needs of the system, and that guarantee optimal behavior, stability, and security in the target deployment. |
| 18/2 | 2026/08/18 11:17 | tool | read-file |
0mArgs:{
"File": "drivers/net/Kconfig",
"FirstLine": 327,
"LineCount": 20
}Results: {
"Contents": " 327:\tconfig NETCONSOLE\n 328:\t\ttristate \"Network console logging support\"\n 329:\t\tdepends on PRINTK\n 330:\t\thelp\n 331:\t\t If you want to log kernel messages over the network, enable this.\n 332:\t\t See \u003cfile:Documentation/networking/netconsole.rst\u003e for details.\n 333:\t\n 334:\tconfig NETCONSOLE_DYNAMIC\n 335:\t\tbool \"Dynamic reconfiguration of logging targets\"\n 336:\t\tdepends on NETCONSOLE \u0026\u0026 SYSFS \u0026\u0026 CONFIGFS_FS \u0026\u0026 \\\n 337:\t\t\t\t!(NETCONSOLE=y \u0026\u0026 CONFIGFS_FS=m)\n 338:\t\tselect PRINTK_EXECUTION_CTX\n 339:\t\thelp\n 340:\t\t This option enables the ability to dynamically reconfigure target\n 341:\t\t parameters (interface, IP addresses, port numbers, MAC addresses)\n 342:\t\t at runtime through a userspace interface exported using configfs.\n 343:\t\t See \u003cfile:Documentation/networking/netconsole.rst\u003e for details.\n 344:\t\n 345:\tconfig NETCONSOLE_EXTENDED_LOG\n 346:\t\tbool \"Set kernel extended message by default\"\n"
} |
| 19/2 | 2026/08/18 11:17 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 13872 output: 34 thoughts: 377 Thoughts: **My Analysis of Netconsole Configuration** Okay, so I'm diving into this `NETCONSOLE` module. First things first, it's clear I'll need `NETCONSOLE` and `NETCONSOLE_DYNAMIC` enabled. Also, `CONFIGFS_FS` is a definite requirement. I'll make a note of this. I should double-check that `PRINTK` and `SYSFS` are enabled since those are usually a given. So far, the `EnableConfigs` list looks like this: `["NETCONSOLE", "NETCONSOLE_DYNAMIC", "CONFIGFS_FS"]`. Now, let's take a closer look at the functions defined in the patch to see if there are other functions I need to take into consideration. I see a few key ones: `netconsole_ratelimit_init`, `netconsole_ratelimited`, `netconsole_take_drops`, and functions related to the rate-limiting parameters like `ratelimit_interval_ms_show`, `ratelimit_burst_show`, `ratelimit_interval_ms_store`, `ratelimit_burst_store`, and `send_ratelimit_notice`. Specifically, I'm interested in the non-static functions, or ones that have their addresses taken. Let me see... `ratelimit_interval_ms_store`, `ratelimit_burst_store`, `ratelimit_interval_ms_show`, and `ratelimit_burst_show` are the ones that jump out. Let's see, is `netconsole_write` address-taken? No, but `netconsole_write_ext` and `netconsole_write_basic` are. Ah, and `netconsole_write` is called from both `netconsole_write_ext` and `netconsole_write_basic`. So I can include `netconsole_write_ext` and `netconsole_write_basic` in my `FocusSymbols` list. And I think `ratelimit_interval_ms_store` and `ratelimit_burst_store` are also going to be important to focus on. Finally, I should verify that `netconsole_write_ext` and `netconsole_write_basic` are even present in the kernel to make sure I am on the right path. |
| 20/2 | 2026/08/18 11:17 | tool | grepper |
0mArgs:{
"Expression": "netconsole_write_ext",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=2613=static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)\n--\ndrivers/net/netconsole.c-2645-\ndrivers/net/netconsole.c:2646:static void netconsole_write_ext(struct console *con __always_unused,\ndrivers/net/netconsole.c-2647-\t\t\t\t struct nbcon_write_context *wctxt)\n--\ndrivers/net/netconsole.c=2842=static struct console netconsole_ext = {\n--\ndrivers/net/netconsole.c-2844-\t.flags = CON_ENABLED | CON_EXTENDED | CON_NBCON | CON_NBCON_ATOMIC_UNSAFE,\ndrivers/net/netconsole.c:2845:\t.write_thread = netconsole_write_ext,\ndrivers/net/netconsole.c:2846:\t.write_atomic = netconsole_write_ext,\ndrivers/net/netconsole.c-2847-\t.device_lock = netconsole_device_lock,\n"
} |
| 21/2 | 2026/08/18 11:17 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 15061 output: 34 thoughts: 419 Thoughts: **My Thought Process on Identifying Focused Symbols** Okay, so we're looking for specific functions to focus on, and yes, I've got a list already. Let's see... I've got: * `ratelimit_interval_ms_store` * `ratelimit_burst_store` * `ratelimit_interval_ms_show` * `ratelimit_burst_show` Now, I need to consider inlining. `netconsole_write` is static, so it might be inlined, along with `send_ratelimit_notice` and `netconsole_ratelimited`. I need to figure out what to put into `FocusSymbols`. So, considering inlining, I have a preliminary list, which is: * `ratelimit_interval_ms_store` * `ratelimit_burst_store` * `ratelimit_interval_ms_show` * `ratelimit_burst_show` * `netconsole_write_ext` * `netconsole_write_basic` Wait a minute, `netconsole_write_ext` and `netconsole_write_basic` might be hot paths if there are many printks, and the prompt says to avoid listing generic hot-path functions. `netconsole_write_ext` is called for every `printk` if netconsole is enabled. Since `printk` can be a hot path, this is a bit of a dilemma. On the other hand, the ratelimit store functions definitely are not hot paths. So, since the goal is to focus on specific configfs store functions, I should focus on the configfs store functions. Let me see if there are other functions related to this... `netconsole_ratelimit_init` is called from `alloc_and_init`, which is called when a new target is created. Hmm... could I add `alloc_and_init` or `make_netconsole_target`? Let's see: `alloc_and_init` is static; it seems that `make_netconsole_target` is the configfs `make_item` callback. |
| 22/2 | 2026/08/18 11:17 | tool | grepper |
0mArgs:{
"Expression": "make_netconsole_target",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=1833=static struct netconsole_target *find_cmdline_target(const char *name)\n--\ndrivers/net/netconsole.c-1853-\ndrivers/net/netconsole.c:1854:static struct config_group *make_netconsole_target(struct config_group *group,\ndrivers/net/netconsole.c-1855-\t\t\t\t\t\t const char *name)\n--\ndrivers/net/netconsole.c=1940=static const struct configfs_group_operations netconsole_subsys_group_ops = {\ndrivers/net/netconsole.c:1941:\t.make_group\t= make_netconsole_target,\ndrivers/net/netconsole.c-1942-\t.drop_item\t= drop_netconsole_target,\n"
} |
| 23/2 | 2026/08/18 11:17 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 16205 output: 220 thoughts: 768 Thoughts: **My Analysis of the Netconsole Rate Limiting Patch** Okay, here's my breakdown of this patch. Initially, I thought `make_netconsole_target` might be relevant, but it's not directly modified. However, the `alloc_and_init` function *is* changed to call `netconsole_ratelimit_init`, so there's an indirect connection. My focus, though, needs to be on the direct entry points for this new rate limiting feature: `ratelimit_interval_ms_store` and `ratelimit_burst_store`. Looking more closely at the patch itself, I see it's introducing `ratelimit_interval_ms` and `ratelimit_burst` as attributes within `netconsole_target_attrs`. It's also adding the corresponding store and show functions: `ratelimit_interval_ms_store`, `ratelimit_burst_store`, `ratelimit_interval_ms_show`, and `ratelimit_burst_show`. Crucially, `netconsole_ratelimited` and `send_ratelimit_notice` are introduced and used within `netconsole_write`. Therefore, my *FocusSymbols* for the fuzzing efforts will be: * `ratelimit_interval_ms_store` * `ratelimit_burst_store` * `ratelimit_interval_ms_show` * `ratelimit_burst_show` I need to consider where the rate limiting actually *happens*. That's within `netconsole_write_ext` and `netconsole_write_basic`. Are these hot paths? Absolutely. Every `printk` that goes through netconsole, when enabled, hits these functions. We should exclude them from direct fuzzing to avoid skewed test distributions, since they are core functionality. Now, on to the configuration aspects. The feature depends on these `EnableConfigs`: * `NETCONSOLE` * `NETCONSOLE_DYNAMIC` * `CONFIGFS_FS` Other dependencies are likely `PRINTK` and `SYSFS`, but those are usually enabled. So, the key dependencies remain the three mentioned above. My reasoning boils down to this: the patch introduces rate limiting to prevent netconsole targets from being overwhelmed by continuous logging. It does this by adding new configfs attributes (`ratelimit_interval_ms`, `ratelimit_burst`) to configure a rate limit *per* target. The core rate limiting logic is implemented within `netconsole_write`, making use of `ratelimit_state`. The changes are accessible via configfs and the printk console write path. The configfs store/show functions are, therefore, prime candidates for fuzzing. I've double-checked that `CONFIGFS_FS` is the correct name, and it is; the relevant `Kconfig` file in `drivers/net` confirms it. I also double-checked the exact names of the store and show functions, and they are as expected: `ratelimit_interval_ms_store`, `ratelimit_burst_store`, `ratelimit_interval_ms_show`, and `ratelimit_burst_show`. I'm ready to use `set-results` to provide the results. |
| 24/2 | 2026/08/18 11:17 | tool | set-results |
0mArgs:{
"EnableConfigs": [
"NETCONSOLE",
"NETCONSOLE_DYNAMIC",
"CONFIGFS_FS"
],
"FocusSymbols": [
"ratelimit_interval_ms_store",
"ratelimit_burst_store",
"ratelimit_interval_ms_show",
"ratelimit_burst_show"
],
"Reasoning": "The patch introduces rate limiting for netconsole targets to prevent a host from saturating the receiving agent with continuous logs. It adds new configfs attributes `ratelimit_interval_ms` and `ratelimit_burst` to configure the rate limit per target. The rate limiting logic is implemented in the console write path using `ratelimit_state`. The changes are reachable via configfs and the printk console write path. The configfs store/show functions are good candidates for fuzzing. The feature requires `CONFIG_NETCONSOLE`, `CONFIG_NETCONSOLE_DYNAMIC`, and `CONFIG_CONFIGFS_FS`.",
"WorthFuzzing": true
}Results: {
"EnableConfigs": [
"NETCONSOLE",
"NETCONSOLE_DYNAMIC",
"CONFIGFS_FS"
],
"FocusSymbols": [
"ratelimit_interval_ms_store",
"ratelimit_burst_store",
"ratelimit_interval_ms_show",
"ratelimit_burst_show"
],
"Reasoning": "The patch introduces rate limiting for netconsole targets to prevent a host from saturating the receiving agent with continuous logs. It adds new configfs attributes `ratelimit_interval_ms` and `ratelimit_burst` to configure the rate limit per target. The rate limiting logic is implemented in the console write path using `ratelimit_state`. The changes are reachable via configfs and the printk console write path. The configfs store/show functions are good candidates for fuzzing. The feature requires `CONFIG_NETCONSOLE`, `CONFIG_NETCONSOLE_DYNAMIC`, and `CONFIG_CONFIGFS_FS`.",
"WorthFuzzing": true
} |
| 25/1 | 2026/08/18 11:17 | action | If |
1mArgs:{
"WorthFuzzing": true
}Results: null |
| 26/2 | 2026/08/18 11:17 | agent | kmsan-evaluator |
1mModel:best-expensive Args: null Results: {
"KMSANReasoning": "The patch introduces rate limiting for netconsole targets. It adds `ratelimit_interval_ms` and `ratelimit_burst` configuration options, and uses `struct ratelimit_state` to track message rates. When messages are dropped, it sends a notice indicating the number of dropped messages.\n\nThe notice is formatted using `scnprintf` into the target's pre-allocated buffer (`nt-\u003ebuf`), and the exact length returned by `scnprintf` is passed to `send_udp`. `scnprintf` fully initializes the bytes it writes, and `send_udp` only reads the specified length, ensuring no uninitialized memory from the buffer is sent over the network.\n\nThe new fields in `struct netconsole_target` are properly initialized: `ratelimit` via `ratelimit_state_init`, and `pending_drops` is zero-initialized since the target structure is allocated with `kzalloc`.\n\nThere are no complex data structures with padding being copied to user space or sent over the network, nor is there any conditional logic depending on uninitialized variables. Any potential memory corruption, out-of-bounds access, or use-after-free bugs would be caught by KASAN. Therefore, a dedicated KMSAN fuzzing session is not required.",
"NeedsKMSAN": false
}Instruction: You are an expert Linux kernel security engineer specializing in kernel memory
error detectors (KASAN and KMSAN). Your job is to review the provided patch series and
determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer)
fuzzing session in addition to standard KASAN fuzzing.
CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN:
- Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable
a comprehensive suite of debugging tools and sanitizers, including KASAN
(out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP
(locking bugs and deadlocks), UB-sanitizers, and memory corruption checks.
- KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap,
or page allocations) and kernel-to-user memory info-leaks.
Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN,
LOCKDEP, OR OTHER STANDARD BUG DETECTORS.
A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY
set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks
that are detected ONLY by KMSAN.
Look holistically at the patch series and surrounding code. Even if no direct
uninitialized field accesses or new buffer allocations are added in the diff itself,
a patch may alter control flow, bounds checking, or data length calculations in ways
that change how the rest of the code operates on existing buffers (e.g. allowing
uninitialized stack/heap memory to be read, copied to user space, or used in control
flow). Do not hesitate to use your code access tools to inspect the surrounding code,
called functions, and callers.
Set NeedsKMSAN=true ONLY IF the patch introduces or modifies:
1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb
attributes, ioctl output arguments, socket options, or BPF buffers) where fields
or structure padding might not be fully initialized/zeroed.
2. Conditional logic or branching that depends on potentially uninitialized variables
or struct fields.
3. Allocation or initialization of complex data structures where uninitialized fields
could be read later in reachable code paths.
4. Bounds checks, lengths, or logic in a way that allows surrounding code to access
uninitialized bytes of existing buffers.
Set NeedsKMSAN=false IF:
- The code changes primarily risk out-of-bounds access, array overflows, NULL pointer
dereferences, locking deadlocks, or use-after-free bugs (these are already caught
by KASAN, LOCKDEP, or standard bug detectors).
- All stack/heap structures touched or introduced by the patch are fully zeroed
or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied.
- The patch does not introduce any risk of uninitialized memory usage or info-leaks.
Use your code access tools to inspect the surrounding code if necessary, then provide
detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch.
Prefer calling several tools at the same time to save round-trips.
Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.
Prompt: For your convenience, here is the diff of the changes:
commit 4906d8bd1febf63967491596728581965fa8da17
Author: syz-cluster <triage@syzkaller.com>
Date: Tue Aug 18 11:16:14 2026 +0000
syz-cluster: applied patch under review
diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst
index 4ab5d7b05cf10..7369cd89ae76c 100644
--- a/Documentation/networking/netconsole.rst
+++ b/Documentation/networking/netconsole.rst
@@ -177,6 +177,49 @@ You can modify these targets in runtime by creating the following targets::
cat cmdline1/remote_ip
10.0.0.3
+Rate limiting
+-------------
+
+Netconsole hands every console message to every enabled target, so a host that
+logs continuously can saturate the receiving agent. Each target carries a token
+bucket that drops messages once the configured rate is exceeded, controlled by
+two files in the target directory:
+
+ ===================== ================================================
+ ratelimit_interval_ms Length of the accounting interval, in
+ milliseconds. Zero, the default, sends
+ everything.
+ ratelimit_burst Messages allowed per interval. Defaults to
+ 10; zero drops every message.
+ ===================== ================================================
+
+Unlike most target parameters, both knobs can be written while the target is
+enabled, which is when a flooding target most likely needs them.
+
+The limit is applied per message, not per packet, so a message big enough to be
+split into several `ncfrag` packets is either sent whole or not at all.
+
+Crash output bypasses the bucket. While an oops, BUG() or panic() is in
+progress every message is sent, whatever the limit says, so a small burst
+cannot cost you part of a crash dump.
+
+A drop leaves nothing on the wire, so the receiver is told what it missed as
+soon as a message gets through again::
+
+ netconsole: 45 messages dropped by rate limit
+
+The notice only travels with the next message the bucket allows. A host that
+goes quiet right after being limited reports the drops later, when it logs
+again, and a target with a `ratelimit_burst` of zero never reports them.
+
+netconsole generates the notice itself instead of logging it, so on an
+extended target the record carries a sequence number of zero.
+
+Capping a target at 500 messages a minute::
+
+ echo 60000 > ratelimit_interval_ms
+ echo 500 > ratelimit_burst
+
Append User Data
----------------
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index b358e5c367351..0af2e5b4335c0 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -49,6 +49,8 @@
#include <linux/rtnetlink.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/clock.h>
MODULE_AUTHOR("Matt Mackall <mpm@selenic.com>");
MODULE_DESCRIPTION("Console driver for network interfaces");
@@ -175,6 +177,8 @@ struct netcons_userdata {
* @sysdata: Cached, formatted string of append
* @sysdata_fields: Sysdata features enabled.
* @msgcounter: Message sent counter.
+ * @ratelimit: Opaque structure to ratelimit messages
+ * @pending_drops: Messages dropped since the last notice was sent.
* @stats: Packet send stats for the target. Used for debugging.
* @state: State of the target.
* Visible from userspace (read-write).
@@ -219,6 +223,8 @@ struct netconsole_target {
u32 sysdata_fields;
/* protected by target_list_lock */
u32 msgcounter;
+ u32 pending_drops;
+ struct ratelimit_state ratelimit;
#endif
struct netconsole_target_stats stats;
enum target_state state;
@@ -282,6 +288,34 @@ static void dynamic_netconsole_mutex_unlock(void)
mutex_unlock(&dynamic_netconsole_mutex);
}
+static void netconsole_ratelimit_init(struct netconsole_target *nt)
+{
+ ratelimit_state_init(&nt->ratelimit, 0, DEFAULT_RATELIMIT_BURST);
+ ratelimit_set_flags(&nt->ratelimit, RATELIMIT_MSG_ON_RELEASE);
+}
+
+static bool netconsole_ratelimited(struct netconsole_target *nt)
+{
+ /* A limit meant for steady-state logging must not eat a crash dump. */
+ if (oops_in_progress)
+ return false;
+
+ if (__ratelimit(&nt->ratelimit))
+ return false;
+
+ nt->pending_drops++;
+
+ return true;
+}
+
+static u32 netconsole_take_drops(struct netconsole_target *nt)
+{
+ u32 drops = nt->pending_drops;
+
+ nt->pending_drops = 0;
+ return drops;
+}
+
#else /* !CONFIG_NETCONSOLE_DYNAMIC */
static int __init dynamic_netconsole_init(void)
@@ -318,6 +352,20 @@ static void dynamic_netconsole_mutex_unlock(void)
{
}
+static void netconsole_ratelimit_init(struct netconsole_target *nt)
+{
+}
+
+static bool netconsole_ratelimited(struct netconsole_target *nt)
+{
+ return false;
+}
+
+static u32 netconsole_take_drops(struct netconsole_target *nt)
+{
+ return 0;
+}
+
#endif /* CONFIG_NETCONSOLE_DYNAMIC */
/* Check if the target was bound by mac address. */
@@ -686,6 +734,7 @@ static struct netconsole_target *alloc_and_init(void)
nt->remote_port = 6666;
eth_broadcast_addr(nt->remote_mac);
nt->state = STATE_DISABLED;
+ netconsole_ratelimit_init(nt);
INIT_WORK(&nt->resume_wq, process_resume_target);
/* Set up the skb pool primitives once; enabling only refills it. */
skb_queue_head_init(&nt->skb_pool);
@@ -912,6 +961,21 @@ static ssize_t transmit_errors_show(struct config_item *item, char *buf)
return sysfs_emit(buf, "%llu\n", xmit_drop_count + enomem_count);
}
+static ssize_t ratelimit_interval_ms_show(struct config_item *item, char *buf)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ return sysfs_emit(buf, "%u\n",
+ jiffies_to_msecs(READ_ONCE(nt->ratelimit.interval)));
+}
+
+static ssize_t ratelimit_burst_show(struct config_item *item, char *buf)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ return sysfs_emit(buf, "%d\n", READ_ONCE(nt->ratelimit.burst));
+}
+
/* configfs helper to display if cpu_nr sysdata feature is enabled */
static ssize_t sysdata_cpu_nr_enabled_show(struct config_item *item, char *buf)
{
@@ -1307,6 +1371,50 @@ static ssize_t remote_mac_store(struct config_item *item, const char *buf,
return ret;
}
+static ssize_t ratelimit_interval_ms_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ unsigned int interval;
+ unsigned long jifs;
+ ssize_t ret;
+
+ ret = kstrtouint(buf, 10, &interval);
+ if (ret)
+ return ret;
+
+ jifs = msecs_to_jiffies(interval);
+ if (jifs > INT_MAX)
+ return -ERANGE;
+
+ dynamic_netconsole_mutex_lock();
+ WRITE_ONCE(nt->ratelimit.interval, jifs);
+ dynamic_netconsole_mutex_unlock();
+
+ return count;
+}
+
+static ssize_t ratelimit_burst_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ unsigned int burst;
+ ssize_t ret;
+
+ ret = kstrtouint(buf, 10, &burst);
+ if (ret)
+ return ret;
+
+ if (burst > INT_MAX)
+ return -ERANGE;
+
+ dynamic_netconsole_mutex_lock();
+ WRITE_ONCE(nt->ratelimit.burst, burst);
+ dynamic_netconsole_mutex_unlock();
+
+ return count;
+}
+
struct userdatum {
struct config_item item;
char value[MAX_EXTRADATA_VALUE_LEN];
@@ -1671,6 +1779,8 @@ CONFIGFS_ATTR_RO(, local_mac);
CONFIGFS_ATTR(, remote_mac);
CONFIGFS_ATTR(, release);
CONFIGFS_ATTR_RO(, transmit_errors);
+CONFIGFS_ATTR(, ratelimit_interval_ms);
+CONFIGFS_ATTR(, ratelimit_burst);
static struct configfs_attribute *netconsole_target_attrs[] = {
&attr_enabled,
@@ -1684,6 +1794,8 @@ static struct configfs_attribute *netconsole_target_attrs[] = {
&attr_local_mac,
&attr_remote_mac,
&attr_transmit_errors,
+ &attr_ratelimit_interval_ms,
+ &attr_ratelimit_burst,
NULL,
};
@@ -2463,6 +2575,34 @@ static void send_msg_udp(struct netconsole_target *nt, const char *msg,
}
}
+static void send_ratelimit_notice(struct netconsole_target *nt, bool extended)
+{
+ int len = 0;
+ u64 ts_usec;
+ u32 drops;
+
+ drops = netconsole_take_drops(nt);
+ if (!drops)
+ return;
+
+ if (extended) {
+ /* append the extended headers */
+ if (nt->release)
+ len = scnprintf(nt->buf, sizeof(nt->buf), "%s,",
+ init_utsname()->release);
+
+ ts_usec = div_u64(local_clock(), NSEC_PER_USEC);
+ len += scnprintf(nt->buf + len, sizeof(nt->buf) - len,
+ "%u,0,%llu,-;", LOGLEVEL_WARNING, ts_usec);
+ }
+
+ len += scnprintf(nt->buf + len, sizeof(nt->buf) - len,
+ "netconsole: %u messages dropped by rate limit\n",
+ drops);
+
+ send_udp(nt, nt->buf, len);
+}
+
/**
* netconsole_write - Generic function to send a msg to all targets
* @wctxt: nbcon write context
@@ -2482,6 +2622,9 @@ static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)
!netif_running(nt->np.dev))
continue;
+ if (netconsole_ratelimited(nt))
+ continue;
+
/* If nbcon_enter_unsafe() fails, just return given netconsole
* lost the ownership, and iterating over the targets will not
* be able to re-acquire.
@@ -2489,6 +2632,8 @@ static void netconsole_write(struct nbcon_write_context *wctxt, bool extended)
if (!nbcon_enter_unsafe(wctxt))
return;
+ send_ratelimit_notice(nt, extended);
+
if (extended)
send_ext_msg_udp(nt, wctxt);
else
diff --git a/tools/testing/selftests/drivers/net/netconsole/Makefile b/tools/testing/selftests/drivers/net/netconsole/Makefile
index f0674c0017fc4..04cce40f162e9 100644
--- a/tools/testing/selftests/drivers/net/netconsole/Makefile
+++ b/tools/testing/selftests/drivers/net/netconsole/Makefile
@@ -10,6 +10,7 @@ TEST_PROGS := \
netcons_cmdline.sh \
netcons_fragmented_msg.sh \
netcons_overflow.sh \
+ netcons_ratelimit.sh \
netcons_resume.sh \
netcons_sysdata.sh \
netcons_torture.sh \
diff --git a/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh b/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh
new file mode 100755
index 0000000000000..38dd1599fe57d
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/netconsole/netcons_ratelimit.sh
@@ -0,0 +1,160 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This test exercises the per-target rate limit. It configures a small burst
+# over an interval long enough that the bucket is never refilled, sends many
+# more messages than the burst allows, and checks that the target stops
+# transmitting once the bucket is empty.
+#
+# Clearing the interval has to restore unlimited delivery and tell the
+# receiver how many messages it missed, which is verified last.
+#
+# Author: Breno Leitao <leitao@debian.org>
+
+set -euo pipefail
+
+SCRIPTDIR=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")
+
+source "${SCRIPTDIR}"/../lib/sh/lib_netcons.sh
+
+# Messages sent while the limit is in place, comfortably above BURST so that
+# the bucket is drained
+MSG_COUNT=50
+BURST=5
+# Long enough that the bucket is not refilled while the test runs
+INTERVAL_MS=60000
+# Default the target starts with, as documented in netconsole.rst
+DEFAULT_BURST=10
+# What the target sends once it can transmit again
+DROP_NOTICE="messages dropped by rate limit"
+
+# The content of kmsg will be saved to the following file
+OUTPUT_FILE="/tmp/${TARGET}"
+
+function count_msgs() {
+ local FILE="${1}"
+
+ if [ ! -f "${FILE}" ]
+ then
+ echo 0
+ return
+ fi
+
+ # grep exits 1 on no match, which is a valid result here
+ grep -c "${MSG}" "${FILE}" || true
+}
+
+function send_msgs() {
+ local COUNT="${1}"
+ local I
+
+ for I in $(seq "${COUNT}")
+ do
+ echo "${MSG}: ${TARGET} ${I}" > /dev/kmsg
+ done
+}
+
+# A freshly created target has to be unlimited, otherwise every existing
+# netconsole user would start dropping messages after an upgrade
+function check_defaults() {
+ local INTERVAL BURST_DEFAULT
+
+ INTERVAL=$(cat "${NETCONS_PATH}"/ratelimit_interval_ms)
+ BURST_DEFAULT=$(cat "${NETCONS_PATH}"/ratelimit_burst)
+
+ if [ "${INTERVAL}" -ne 0 ] ||
+ [ "${BURST_DEFAULT}" -ne "${DEFAULT_BURST}" ]
+ then
+ echo "FAIL: unexpected rate limit defaults:" \
+ "interval=${INTERVAL} burst=${BURST_DEFAULT}" >&2
+ exit "${ksft_fail}"
+ fi
+}
+
+function check_limited() {
+ local RECEIVED
+
+ RECEIVED=$(count_msgs "${OUTPUT_FILE}")
+
+ # Unrelated kernel messages share the bucket, so fewer than BURST of
+ # ours can get through, but never more
+ if [ "${RECEIVED}" -gt "${BURST}" ]
+ then
+ echo "FAIL: received ${RECEIVED} messages with ratelimit_burst=${BURST}" >&2
+ cat "${OUTPUT_FILE}" >&2
+ exit "${ksft_fail}"
+ fi
+}
+
+# The notice below travels ahead of the message that reopened the bucket, so
+# waiting for the file to appear is not enough
+function msg_received() {
+ grep -q "${MSG}" "${OUTPUT_FILE}" 2> /dev/null
+}
+
+# The messages lost above have to be reported to the receiver
+function check_drops_reported() {
+ if ! grep -q "${DROP_NOTICE}" "${OUTPUT_FILE}"
+ then
+ echo "FAIL: no rate limit notice in ${OUTPUT_FILE}" >&2
+ cat "${OUTPUT_FILE}" >&2
+ exit "${ksft_fail}"
+ fi
+}
+
+# ========== #
+# Start here #
+# ========== #
+
+modprobe netdevsim 2> /dev/null || true
+modprobe netconsole 2> /dev/null || true
+
+# Check for basic system dependency and exit if not found
+check_for_dependencies
+# Remove the namespace, interfaces and netconsole target on exit
+trap cleanup EXIT
+
+# Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)
+echo "6 5" > /proc/sys/kernel/printk
+# Create one namespace and two interfaces
+set_network
+# Create a dynamic target for netconsole
+create_dynamic_target
+
+check_defaults
+
+# Set the burst before the interval, so that no message escapes while the
+# target still carries the default burst
+echo "${BURST}" > "${NETCONS_PATH}"/ratelimit_burst
+echo "${INTERVAL_MS}" > "${NETCONS_PATH}"/ratelimit_interval_ms
+
+listen_port_and_save_to "${OUTPUT_FILE}" &
+wait_for_port "${NAMESPACE}" "${PORT}" "ipv4"
+send_msgs "${MSG_COUNT}"
+# This half of the test is about messages that never arrive, so there is
+# nothing to busywait on
+sleep 1
+pkill_socat
+check_limited
+rm -f "${OUTPUT_FILE}"
+
+# Dropping the interval back to zero has to make the target unlimited again
+echo 0 > "${NETCONS_PATH}"/ratelimit_interval_ms
+
+listen_port_and_save_to "${OUTPUT_FILE}" &
+wait_for_port "${NAMESPACE}" "${PORT}" "ipv4"
+send_msgs 1
+if ! busywait "${BUSYWAIT_TIMEOUT}" msg_received
+then
+ echo "FAIL: Timed out waiting (${BUSYWAIT_TIMEOUT} ms) for netconsole" \
+ "message in ${OUTPUT_FILE} after clearing the rate limit" >&2
+ exit "${ksft_fail}"
+fi
+validate_msg "${OUTPUT_FILE}"
+check_drops_reported
+pkill_socat
+rm -f "${OUTPUT_FILE}"
+
+trap - EXIT
+cleanup
+exit "${ksft_pass}"
|
| 27/3 | 2026/08/18 11:17 | llm | kmsan-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 6826 output: 33 thoughts: 1192 Thoughts: **Analyzing the Netconsole Rate Limiting Patch**
Okay, so I'm looking at this patch that adds rate limiting to netconsole. The core of it seems pretty straightforward: it modifies `drivers/net/netconsole.c`, introduces `ratelimit_interval_ms` and `ratelimit_burst` to the netconsole target configuration, and uses a `struct ratelimit_state` within `struct netconsole_target`. A `pending_drops` counter is added; when the rate limit is exceeded, messages get dropped and this counter increments. When a message *is* allowed, it checks if `pending_drops` is > 0 and, if so, sends a "netconsole: %u messages dropped by rate limit\n" notice. This notice is sent via `send_ratelimit_notice()`.
Now, let's dive into `send_ratelimit_notice()`. I'm focusing on that function because that's where the rate limiting is actually *announced*. I'm reading the code, and my main concern is always around potential memory issues, specifically uninitialized memory or buffer overflows.
```c
+static void send_ratelimit_notice(struct netconsole_target *nt, bool extended)
+{
+ int len = 0;
+ u64 ts_usec;
+ u32 drops;
+
+ drops = netconsole_take_drops(nt);
+ if (!drops)
+ return;
+
+ if (extended) {
+ /* append the extended headers */
+ if (nt->release)
+ len = scnprintf(nt->buf, sizeof(nt->buf), "%s,",
+ init_utsname()->release);
+
+ ts_usec = div_u64(local_clock(), NSEC_PER_USEC);
+ len += scnprintf(nt->buf + len, sizeof(nt->buf) - len,
+ "%u,0,%llu,-;", LOGLEVEL_WARNING, ts_usec);
+ }
+
+ len += scnprintf(nt->buf + len, sizeof(nt->buf) - len,
+ "netconsole: %u messages dropped by rate limit\n",
+ drops);
+
+ send_udp(nt, nt->buf, len);
+}
```
Okay, the first thing I notice is that the notice message is formatted into `nt->buf`, and then `send_udp()` is called. The key here is understanding exactly *how* `nt->buf` is used. My initial thought is, is `nt->buf` properly initialized? Or could we be leaking uninitialized memory?
`scnprintf` writes a null-terminated string. `scnprintf` will return the number of characters written *excluding* the null terminator. The code then calls `send_udp(nt, nt->buf, len)`, so it seems that it's correctly sending exactly `len` bytes from the buffer.
Now, consider the `if (nt->release)` block. If `nt->release` is true, then we append additional headers. If it's false, `len` is initialized to 0. I'm pretty sure that with each subsequent call to `scnprintf`, it's adding to the existing content and ensuring it is null-terminated. And, in all cases, we're using the returned length value. The final call to `scnprintf` will write the "netconsole: ..." message. The `scnprintf` function *should* handle the null termination. Thus, `send_udp()` is only reading the number of characters we've explicitly written to the buffer via `scnprintf` . So, no, there isn't an uninitialized memory issue. The combination of `scnprintf` and the subsequent use of `len` in `send_udp()` prevents any uninitialized data from being transmitted.
Next, I need to verify that `send_udp` and `nt->buf` are correctly defined in `drivers/net/netconsole.c`. I have confirmed that `nt->buf` is indeed a character array with a defined size. Checking `send_udp` confirms that it takes a pointer to a buffer and a length, and it simply sends a UDP packet containing those bytes. Since `scnprintf` is formatting a string into the buffer correctly, that means we're in good shape.
Now, I'll quickly check the `netconsole_target` struct to make sure there are no other potential gotchas. I saw `msgcounter`, `pending_drops`, and `ratelimit`. These are primitive types and a struct, which is
|
| 28/3 | 2026/08/18 11:17 | tool | grepper |
0mArgs:{
"Expression": "alloc_and_init",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=398=static void refill_skbs_work_handler(struct work_struct *work)\n--\ndrivers/net/netconsole.c-406-/* Seed the per-target skb pool that find_skb() falls back to. The queue\ndrivers/net/netconsole.c:407: * head and refill work are set up once in alloc_and_init(); this only\ndrivers/net/netconsole.c-408- * (re)fills the pool. Pair with netconsole_skb_pool_flush().\n--\ndrivers/net/netconsole.c=657=static void process_resume_target(struct work_struct *work)\n--\ndrivers/net/netconsole.c-717- */\ndrivers/net/netconsole.c:718:static struct netconsole_target *alloc_and_init(void)\ndrivers/net/netconsole.c-719-{\n--\ndrivers/net/netconsole.c=1854=static struct config_group *make_netconsole_target(struct config_group *group,\n--\ndrivers/net/netconsole.c-1872-\ndrivers/net/netconsole.c:1873:\tnt = alloc_and_init();\ndrivers/net/netconsole.c-1874-\tif (!nt)\n--\ndrivers/net/netconsole.c=2768=static struct netconsole_target *alloc_param_target(char *target_config,\n--\ndrivers/net/netconsole.c-2773-\ndrivers/net/netconsole.c:2774:\tnt = alloc_and_init();\ndrivers/net/netconsole.c-2775-\tif (!nt) {\n"
} |
| 29/3 | 2026/08/18 11:17 | llm | kmsan-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 9510 output: 36 thoughts: 20 Thoughts: Here's my take on those thoughts: **Analyzing `alloc_and_init` for `kzalloc` Usage** Okay, so I need to dive into the `alloc_and_init` function. The primary question here is whether or not this function utilizes `kzalloc` internally. My immediate goal is to confirm whether the memory allocation within `alloc_and_init` is zeroed out. If it is, that's a key piece of information for understanding its behavior and potential implications for my area of expertise, whatever it may be. I'll need to carefully examine the code within `alloc_and_init`, specifically looking for direct calls to `kzalloc` or any allocation pathways that might ultimately lead to a zeroing-out operation. I'm going to be looking for any indications as to which allocation function is utilized. |
| 30/3 | 2026/08/18 11:17 | tool | read-file |
0mArgs:{
"File": "drivers/net/netconsole.c",
"FirstLine": 718,
"LineCount": 50
}Results: {
"Contents": " 718:\tstatic struct netconsole_target *alloc_and_init(void)\n 719:\t{\n 720:\t\tstruct netconsole_target *nt;\n 721:\t\n 722:\t\tnt = kzalloc_obj(*nt);\n 723:\t\tif (!nt)\n 724:\t\t\treturn nt;\n 725:\t\n 726:\t\tif (IS_ENABLED(CONFIG_NETCONSOLE_EXTENDED_LOG))\n 727:\t\t\tnt-\u003eextended = true;\n 728:\t\tif (IS_ENABLED(CONFIG_NETCONSOLE_PREPEND_RELEASE))\n 729:\t\t\tnt-\u003erelease = true;\n 730:\t\n 731:\t\tnt-\u003enp.name = \"netconsole\";\n 732:\t\tstrscpy(nt-\u003enp.dev_name, \"eth0\", IFNAMSIZ);\n 733:\t\tnt-\u003elocal_port = 6665;\n 734:\t\tnt-\u003eremote_port = 6666;\n 735:\t\teth_broadcast_addr(nt-\u003eremote_mac);\n 736:\t\tnt-\u003estate = STATE_DISABLED;\n 737:\t\tnetconsole_ratelimit_init(nt);\n 738:\t\tINIT_WORK(\u0026nt-\u003eresume_wq, process_resume_target);\n 739:\t\t/* Set up the skb pool primitives once; enabling only refills it. */\n 740:\t\tskb_queue_head_init(\u0026nt-\u003eskb_pool);\n 741:\t\tINIT_WORK(\u0026nt-\u003erefill_wq, refill_skbs_work_handler);\n 742:\t\n 743:\t\treturn nt;\n 744:\t}\n 745:\t\n 746:\t/* Clean up every target in the cleanup_list and move the clean targets back to\n 747:\t * the main target_list.\n 748:\t */\n 749:\tstatic void netconsole_process_cleanups_core(void)\n 750:\t{\n 751:\t\tstruct netconsole_target *nt, *tmp;\n 752:\t\tunsigned long flags;\n 753:\t\n 754:\t\t/* The cleanup needs RTNL locked */\n 755:\t\tASSERT_RTNL();\n 756:\t\n 757:\t\tmutex_lock(\u0026target_cleanup_list_lock);\n 758:\t\tlist_for_each_entry_safe(nt, tmp, \u0026target_cleanup_list, list) {\n 759:\t\t\t/* all entries in the cleanup_list needs to be disabled */\n 760:\t\t\tWARN_ON_ONCE(nt-\u003estate == STATE_ENABLED);\n 761:\t\t\tnetconsole_skb_pool_flush(nt);\n 762:\t\t\tnetcons_release_dev(nt);\n 763:\t\t\t/* moved the cleaned target to target_list. Need to hold both\n 764:\t\t\t * locks\n 765:\t\t\t */\n 766:\t\t\tspin_lock_irqsave(\u0026target_list_lock, flags);\n 767:\t\t\tlist_move(\u0026nt-\u003elist, \u0026target_list);\n"
} |
| 31/3 | 2026/08/18 11:17 | llm | kmsan-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 10546 output: 34 thoughts: 749 Thoughts: **Analyzing the Netconsole Rate Limiting Implementation** Okay, so I'm looking at this netconsole rate limiting code, and I need to be sure it's sound. First, `kzalloc_obj(*nt)` is being used, which is the same as calling `kzalloc` with the size of the `netconsole_target` struct, and that's good; it means everything's zero-initialized. I'd expect `pending_drops` to be zero initially, and the `ratelimit` structure is initialized using `netconsole_ratelimit_init`, which calls `ratelimit_state_init`. No immediate red flags. Now, let's dive into the details, specifically focusing on potential race conditions or buffer overflows. I'll examine the functions that interact with the rate limiting mechanism. The first is `ratelimit_interval_ms_store`. Seems reasonable; it converts the interval from milliseconds to jiffies, checks for integer overflow when converting to jiffies, and then uses `WRITE_ONCE` to update the `interval` field in the `ratelimit` struct within a mutex. That's a safe and effective way to handle concurrent access. The integer conversion is correct, as is the handling of the mutex. Next, I need to look at `netconsole_ratelimited`. This checks if an oops is in progress, returning false if it is (important, we don't want to rate limit crash dumps). It then calls `__ratelimit` and increments `nt->pending_drops` if the rate limit is exceeded. No issues here. Finally, I'm checking `send_ratelimit_notice`. This is where things get interesting, and potentially dangerous. The code checks `nt->pending_drops`, and formats a string into `nt->buf`. It uses `scnprintf`, which is good since it's safe to use with bounded buffers, but *is the buffer large enough?* The code *does* use `sizeof(nt->buf)` in `scnprintf`, so that's good. But I need to confirm the size of `nt->buf` to be completely certain. I need to make sure the size is large enough to handle all the possible formatted string lengths. Now, let me check the definition of `struct netconsole_target` to confirm. |
| 32/3 | 2026/08/18 11:18 | tool | grepper |
0mArgs:{
"Expression": "struct netconsole_target \\{",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=165=struct netcons_userdata {\n--\ndrivers/net/netconsole.c-213- */\ndrivers/net/netconsole.c:214:struct netconsole_target {\ndrivers/net/netconsole.c-215-\tstruct list_head\tlist;\n"
} |
| 33/3 | 2026/08/18 11:18 | llm | kmsan-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 11922 output: 36 thoughts: 11 Thoughts: Here's my take on the `struct netconsole_target`, from my expert perspective: **Diving into `struct netconsole_target`** Okay, let's dissect this `netconsole_target` struct. Immediately, I'm thinking about the implications for network debugging at the kernel level. This struct is the heart of where the netconsole driver stores information about a particular target system it's supposed to send console messages to. It's essentially the descriptor for each remote console we're trying to reach. First off, I'd be looking at the socket address information. It has to contain the IP address (v4 or v6, most likely) and the UDP port number of the remote machine's netconsole listener. That's the baseline. The fields that hold this info are the most critical. I'd be cross-referencing this structure with the socket and UDP code, making sure the address families and port handling are consistent and robust. I need to make sure this is all being managed thread-safely, too. We don’t want to be in a situation where data races prevent the messages from getting through. Then, there's probably some state tracking. Is it actively connected or trying to reconnect? There's probably a flag indicating whether the socket is ready to accept data. Some kind of error counter or timestamp might exist to see how long it's been since a successful transmission and see if a target is permanently unreachable. I'd expect an exponential backoff strategy if the target is down. I'm assuming there's some kind of locking mechanism associated with this struct. If the kernel has multiple threads or interrupt handlers potentially trying to use the same target at the same time, this needs to be locked down to prevent corruption. A spinlock or a mutex would be typical here. I'd have to make sure it's being used correctly and isn't a bottleneck. What kind of interrupt contexts are these locking primitives able to function in? Finally, there will probably be some configuration options. Maybe an MTU setting to tune for different network environments. Perhaps a flag to control whether timestamps are included in the messages. Possibly even QoS settings. I'm already mentally linking these to the broader netconsole configuration. I want to see how these settings can be changed at runtime, and if there is a way to change them without causing the whole thing to lock up. So, in essence, I'm expecting this struct to encapsulate all the necessary parameters and state for communicating debug information to a remote system. It’s a pretty fundamental building block in enabling remote kernel debugging, and its design has to be rock-solid to keep things running when a system is otherwise down. |
| 34/3 | 2026/08/18 11:18 | tool | read-file |
0mArgs:{
"File": "drivers/net/netconsole.c",
"FirstLine": 214,
"LineCount": 40
}Results: {
"Contents": " 214:\tstruct netconsole_target {\n 215:\t\tstruct list_head\tlist;\n 216:\t#ifdef\tCONFIG_NETCONSOLE_DYNAMIC\n 217:\t\tstruct config_group\tgroup;\n 218:\t\tstruct config_group\tuserdata_group;\n 219:\t\tstruct netcons_userdata __rcu *userdata;\n 220:\t\tchar\t\t\tsysdata[MAX_EXTRADATA_ENTRY_LEN * MAX_SYSDATA_ITEMS];\n 221:\t\n 222:\t\t/* bit-wise with sysdata_feature bits */\n 223:\t\tu32\t\t\tsysdata_fields;\n 224:\t\t/* protected by target_list_lock */\n 225:\t\tu32\t\t\tmsgcounter;\n 226:\t\tu32\t\t\tpending_drops;\n 227:\t\tstruct ratelimit_state\tratelimit;\n 228:\t#endif\n 229:\t\tstruct netconsole_target_stats stats;\n 230:\t\tenum target_state\tstate;\n 231:\t\tbool\t\t\textended;\n 232:\t\tbool\t\t\trelease;\n 233:\t\tstruct netpoll\t\tnp;\n 234:\t\tunion inet_addr\t\tlocal_ip, remote_ip;\n 235:\t\tbool\t\t\tipv6;\n 236:\t\tu16\t\t\tlocal_port, remote_port;\n 237:\t\tu8\t\t\tremote_mac[ETH_ALEN];\n 238:\t\t/* protected by target_list_lock; +1 gives scnprintf() room for its\n 239:\t\t * NUL terminator so a full MAX_PRINT_CHUNK payload is not truncated\n 240:\t\t */\n 241:\t\tchar\t\t\tbuf[MAX_PRINT_CHUNK + 1];\n 242:\t\tstruct work_struct\tresume_wq;\n 243:\t\tstruct sk_buff_head\tskb_pool;\n 244:\t\tstruct work_struct\trefill_wq;\n 245:\t};\n 246:\t\n 247:\t#ifdef\tCONFIG_NETCONSOLE_DYNAMIC\n 248:\t\n 249:\tstatic struct configfs_subsystem netconsole_subsys;\n 250:\tstatic DEFINE_MUTEX(dynamic_netconsole_mutex);\n 251:\t\n 252:\tstatic int __init dynamic_netconsole_init(void)\n 253:\t{\n"
} |
| 35/3 | 2026/08/18 11:18 | llm | kmsan-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 13160 output: 31 thoughts: 331 Thoughts: **My Analysis of the `send_ratelimit_notice` Function** Okay, let me break this down. We're using `buf`, which is a character array, `char buf[MAX_PRINT_CHUNK + 1]`. And `MAX_PRINT_CHUNK` looks to be around 1000, so that's a reasonable size for a buffer. The string we're formatting in `send_ratelimit_notice` is `%s, %u,0,%llu,-; netconsole: %u messages dropped by rate limit\n`. Based on the typical values of release strings, and the numerical values, this should easily fit within `MAX_PRINT_CHUNK + 1`. Now, the important part: are we sending any uninitialized memory? `scnprintf` handles that, writing characters and returning the length. And `send_udp` only sends *exactly* `len` bytes. Since `scnprintf` populates all `len` bytes, no worries there, nothing is uninitialized during the sending. What about uninitialized data being *read*? `nt->release` is a boolean, so that's fine. `init_utsname()->release` is a string, and `local_clock()` returns a `u64`. Then `drops` is a `u32`. Okay, so those are all initialized values. We're good. Is there any uninitialized memory related to `nt->ratelimit`? No, because it is initialized by `ratelimit_state_init`. And `nt->pending_drops` is also zeroed out by `kzalloc`. So, that's covered. The only remaining question is how `send_udp` works internally. To be completely sure, I'll need to double-check the implementation of `send_udp` to ensure it doesn't try to read beyond the `len` bytes passed to it. But from what I have seen so far I do not expect any issues. |
| 36/3 | 2026/08/18 11:18 | tool | grepper |
0mArgs:{
"Expression": "send_udp",
"PathPrefix": "drivers/net/netconsole.c"
}Results: {
"Output": "drivers/net/netconsole.c=2262=static void push_ipv6(struct netconsole_target *nt, struct sk_buff *skb,\n--\ndrivers/net/netconsole.c-2285-\ndrivers/net/netconsole.c:2286:static int netpoll_send_udp(struct netconsole_target *nt, const char *msg,\ndrivers/net/netconsole.c-2287-\t\t\t int len)\n--\ndrivers/net/netconsole.c-2323-/**\ndrivers/net/netconsole.c:2324: * send_udp - Wrapper for netpoll_send_udp that counts errors\ndrivers/net/netconsole.c-2325- * @nt: target to send message to\n--\ndrivers/net/netconsole.c-2328- *\ndrivers/net/netconsole.c:2329: * Calls netpoll_send_udp and classifies the return value. If an error\ndrivers/net/netconsole.c-2330- * occurred it increments statistics in nt-\u003estats accordingly.\ndrivers/net/netconsole.c:2331: * Only calls netpoll_send_udp if CONFIG_NETCONSOLE_DYNAMIC is disabled.\ndrivers/net/netconsole.c-2332- */\ndrivers/net/netconsole.c:2333:static void send_udp(struct netconsole_target *nt, const char *msg, int len)\ndrivers/net/netconsole.c-2334-{\ndrivers/net/netconsole.c:2335:\tint result = netpoll_send_udp(nt, msg, len);\ndrivers/net/netconsole.c-2336-\n--\ndrivers/net/netconsole.c=2350=static void send_msg_no_fragmentation(struct netconsole_target *nt,\n--\ndrivers/net/netconsole.c-2382-\ndrivers/net/netconsole.c:2383:\tsend_udp(nt, nt-\u003ebuf, msg_len);\ndrivers/net/netconsole.c-2384-}\n--\ndrivers/net/netconsole.c=2394=static void send_fragmented_body(struct netconsole_target *nt,\n--\ndrivers/net/netconsole.c-2481-\ndrivers/net/netconsole.c:2482:\t\tsend_udp(nt, nt-\u003ebuf, buf_offset);\ndrivers/net/netconsole.c-2483-\t}\n--\ndrivers/net/netconsole.c=2532=static void send_ext_msg_udp(struct netconsole_target *nt,\n--\ndrivers/net/netconsole.c-2540-\ndrivers/net/netconsole.c:2541:\t/* Keeps the payload picked below alive until the last send_udp(). */\ndrivers/net/netconsole.c-2542-\trcu_read_lock();\n--\ndrivers/net/netconsole.c=2564=static void send_msg_udp(struct netconsole_target *nt, const char *msg,\n--\ndrivers/net/netconsole.c-2571-\t\tfrag = min(left, MAX_PRINT_CHUNK);\ndrivers/net/netconsole.c:2572:\t\tsend_udp(nt, tmp, frag);\ndrivers/net/netconsole.c-2573-\t\ttmp += frag;\n--\ndrivers/net/netconsole.c=2578=static void send_ratelimit_notice(struct netconsole_target *nt, bool extended)\n--\ndrivers/net/netconsole.c-2602-\ndrivers/net/netconsole.c:2603:\tsend_udp(nt, nt-\u003ebuf, len);\ndrivers/net/netconsole.c-2604-}\n"
} |
| 37/3 | 2026/08/18 11:18 | llm | kmsan-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 14885 output: 292 thoughts: 1653 Thoughts: **Analysis of the Netconsole Rate Limiting Patch** Okay, let's break this down. First, the `send_udp` function itself looks solid. It's properly taking a `const char *msg` and `int len`, allocating an SKB, and copying `len` bytes. There's no risk of leaking uninitialized memory there, at least not in the original call chain. Now, reviewing the patch itself... I'm seeing the introduction of `netconsole_ratelimit_init`, `netconsole_ratelimited`, and `netconsole_take_drops`. The init function just sets up the `ratelimit_state` structure, which appears standard. The `netconsole_ratelimited` function utilizes `__ratelimit`, a well-known kernel function, and importantly, it includes a check for `oops_in_progress` to avoid rate-limiting during a crash dump. That's a good safeguard. `netconsole_take_drops` appears safe, simply resetting the counter. The sysfs interfaces for the rate limiting parameters (interval and burst) are also fine, using `READ_ONCE` to ensure atomicity. The store functions are also safe, using mutexes around the writes to `ratelimit.interval` and `ratelimit.burst`, and they are properly validating the input values using `kstrtouint` and avoiding integer overflows. That's all standard, safe kernel practice. Then we have `send_ratelimit_notice`. This is the interesting bit where the dropped message count is formatted. The formatting function, `scnprintf`, is correct in this context, always ensuring the string is properly terminated, and initialized up to len, returning len which is the number of bytes that have been formatted to the buffer. The extended headers are conditional, but the formatting is correct. The call to `send_udp` uses the correct `len` value. The function seems safe. Finally, the added logic in `netconsole_write` properly checks if a target is ratelimited *before* calling `nbcon_enter_unsafe` (important!), and that is also where we see the rate limiting notification being sent, with the right formatting. My final conclusion is this patch does *not* introduce a risk of uninitialized memory usage, nor an info leak to user-space or the network. The struct fields are properly initialized. The `scnprintf` calls and the subsequent use of `len` in `send_udp` prevent any accidental transmission of uninitialized memory. Therefore, I believe KMSAN is not necessary here. Standard kernel bug detectors like KASAN are sufficient. I will now set the result as `NeedsKMSAN=false` and provide my reasoning. |
| 38/3 | 2026/08/18 11:18 | tool | set-results |
0mArgs:{
"KMSANReasoning": "The patch introduces rate limiting for netconsole targets. It adds `ratelimit_interval_ms` and `ratelimit_burst` configuration options, and uses `struct ratelimit_state` to track message rates. When messages are dropped, it sends a notice indicating the number of dropped messages.\n\nThe notice is formatted using `scnprintf` into the target's pre-allocated buffer (`nt-\u003ebuf`), and the exact length returned by `scnprintf` is passed to `send_udp`. `scnprintf` fully initializes the bytes it writes, and `send_udp` only reads the specified length, ensuring no uninitialized memory from the buffer is sent over the network.\n\nThe new fields in `struct netconsole_target` are properly initialized: `ratelimit` via `ratelimit_state_init`, and `pending_drops` is zero-initialized since the target structure is allocated with `kzalloc`.\n\nThere are no complex data structures with padding being copied to user space or sent over the network, nor is there any conditional logic depending on uninitialized variables. Any potential memory corruption, out-of-bounds access, or use-after-free bugs would be caught by KASAN. Therefore, a dedicated KMSAN fuzzing session is not required.",
"NeedsKMSAN": false
}Results: {
"KMSANReasoning": "The patch introduces rate limiting for netconsole targets. It adds `ratelimit_interval_ms` and `ratelimit_burst` configuration options, and uses `struct ratelimit_state` to track message rates. When messages are dropped, it sends a notice indicating the number of dropped messages.\n\nThe notice is formatted using `scnprintf` into the target's pre-allocated buffer (`nt-\u003ebuf`), and the exact length returned by `scnprintf` is passed to `send_udp`. `scnprintf` fully initializes the bytes it writes, and `send_udp` only reads the specified length, ensuring no uninitialized memory from the buffer is sent over the network.\n\nThe new fields in `struct netconsole_target` are properly initialized: `ratelimit` via `ratelimit_state_init`, and `pending_drops` is zero-initialized since the target structure is allocated with `kzalloc`.\n\nThere are no complex data structures with padding being copied to user space or sent over the network, nor is there any conditional logic depending on uninitialized variables. Any potential memory corruption, out-of-bounds access, or use-after-free bugs would be caught by KASAN. Therefore, a dedicated KMSAN fuzzing session is not required.",
"NeedsKMSAN": false
} |
| Total Calls | Total Tokens | Avg Tokens | Total Duration (Seconds) | Avg Duration (Seconds) |
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| Total Calls | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|