AI Trajectory

null

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE"
  ],
  "FocusSymbols": [
    "tls_device_sendmsg",
    "tls_device_splice_eof"
  ],
  "KMSANReasoning": "The patch modifies the condition in `tls_push_data` to prevent leaving a TLS record open if its fragment count (`num_frags`) has reached `MAX_SKB_FRAGS - 1`. Prior to this patch, if `size == 0` and `MSG_MORE` was set, the code would break out of the loop and leave the record open, even if `num_frags` was already at the maximum allowed value. On the next call to `tls_push_data`, `tls_append_frag` could be called on this open record, which would increment `num_frags` beyond `MAX_SKB_FRAGS` and cause an out-of-bounds read and write on the `record-\u003efrags` array.\n\nThis is a classic array overflow / out-of-bounds access bug. KASAN is specifically designed to detect out-of-bounds accesses and will reliably catch this bug. There is no uninitialized memory usage or information leak to user space involved here. Therefore, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false,
  "Reasoning": "The patch modifies the fragmentation logic in `tls_push_data` for TLS hardware offload when `MSG_MORE` is used. This is a functional change in the TLS subsystem that can be triggered from userspace via `sendmsg` or `splice` on a TLS socket with hardware offload enabled.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 89b4054378591fc8b2c520685443171bb9566d3a\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Sun Aug 23 09:38:18 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/tls/tls_device.c b/net/tls/tls_device.c\nindex 37bb06a8e8f5b..f11d0528fc431 100644\n--- a/net/tls/tls_device.c\n+++ b/net/tls/tls_device.c\n@@ -531,7 +531,8 @@ static int tls_push_data(struct sock *sk,\n \t\tif (!size) {\n last_record:\n \t\t\ttls_push_record_flags = flags;\n-\t\t\tif (flags \u0026 MSG_MORE) {\n+\t\t\tif ((flags \u0026 MSG_MORE) \u0026\u0026\n+\t\t\t    record-\u003enum_frags \u003c MAX_SKB_FRAGS - 1) {\n \t\t\t\tmore = true;\n \t\t\t\tbreak;\n \t\t\t}\n"
}

best-expensive

null

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE"
  ],
  "FocusSymbols": [
    "tls_device_sendmsg",
    "tls_device_splice_eof"
  ],
  "Reasoning": "The patch modifies the fragmentation logic in `tls_push_data` for TLS hardware offload when `MSG_MORE` is used. This is a functional change in the TLS subsystem that can be triggered from userspace via `sendmsg` or `splice` on a TLS socket with hardware offload enabled.",
  "WorthFuzzing": true
}

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.

For your convenience, here is the diff of the changes:
commit 89b4054378591fc8b2c520685443171bb9566d3a
Author: syz-cluster <triage@syzkaller.com>
Date:   Sun Aug 23 09:38:18 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 37bb06a8e8f5b..f11d0528fc431 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -531,7 +531,8 @@ static int tls_push_data(struct sock *sk,
 		if (!size) {
 last_record:
 			tls_push_record_flags = flags;
-			if (flags & MSG_MORE) {
+			if ((flags & MSG_MORE) &&
+			    record->num_frags < MAX_SKB_FRAGS - 1) {
 				more = true;
 				break;
 			}

gemini-3.1-pro-preview

null

null

							input: 1987
							output: 34
							thoughts: 102
						

**Analyzing a TLS Patch**

Okay, so I'm looking at this patch that's been applied to `net/tls/tls_device.c`. From what I see, it’s specifically targeting the `tls_push_data` function. The key here is how they're handling the `MSG_MORE` flag in relation to fragmentation. It looks like they've added a check: `record->num_frags < MAX_SKB_FRAGS - 1` before setting `more = true`. That's interesting; they're essentially limiting how much the data can be fragmented when `MSG_MORE` is also set. This seems like a functional change within the TLS subsystem – the behavior is different now in how it handles these scenarios. I need to dig into `tls_push_data` itself within `net/tls/tls_device.c` to see the complete picture and understand the rationale behind this change and its potential impact. I need to understand what triggered this, and ensure it won't impact performance.

{
  "Expression": "tls_push_data",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "Output": "net/tls/tls_device.c=396=static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)\n--\nnet/tls/tls_device.c-420-\nnet/tls/tls_device.c:421:static int tls_push_data(struct sock *sk,\nnet/tls/tls_device.c-422-\t\t\t struct iov_iter *iter,\n--\nnet/tls/tls_device.c=566=int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\n--\nnet/tls/tls_device.c-583-\nnet/tls/tls_device.c:584:\trc = tls_push_data(sk, \u0026msg-\u003emsg_iter, size, msg-\u003emsg_flags,\nnet/tls/tls_device.c-585-\t\t\t   record_type);\n--\nnet/tls/tls_device.c=593=void tls_device_splice_eof(struct socket *sock)\n--\nnet/tls/tls_device.c-608-\t\tiov_iter_bvec(\u0026iter, ITER_SOURCE, NULL, 0, 0);\nnet/tls/tls_device.c:609:\t\ttls_push_data(sk, \u0026iter, 0, 0, TLS_RECORD_TYPE_DATA);\nnet/tls/tls_device.c-610-\t}\n--\nnet/tls/tls_device.c=676=static int tls_device_push_pending_record(struct sock *sk, int flags)\n--\nnet/tls/tls_device.c-680-\tiov_iter_kvec(\u0026iter, ITER_SOURCE, NULL, 0, 0);\nnet/tls/tls_device.c:681:\treturn tls_push_data(sk, \u0026iter, 0, flags, TLS_RECORD_TYPE_DATA);\nnet/tls/tls_device.c-682-}\n"
}

gemini-3.1-pro-preview

null

null

							input: 2849
							output: 28
							thoughts: 78
						

**My Initial Assessment of the Patch's Impact**

Okay, so the `tls_push_data` function is central here. I see it's triggered from several key areas: `tls_device_sendmsg`, `tls_device_splice_eof`, and `tls_device_push_pending_record`. That immediately raises my eyebrows. Anytime a function is called from those points, particularly when splicing is involved, I know we're talking about core TLS record handling and transmission. The patch specifically messes with record fragmentation when `MSG_MORE` is in play. The subtle interaction between fragmentation and the socket flag has caused serious issues in the past, including several vulnerabilities.

Given that context, my gut reaction is that this *absolutely* screams for fuzzing. The interplay of fragmentation, `MSG_MORE`, and the various call points of `tls_push_data` is a prime target for buffer overflows, integer overflows, or off-by-one errors. It is likely that new attack surfaces are being created here. I'm already envisioning potential attack vectors involving maliciously crafted records with carefully manipulated sizes and flags.

So, the next step is crystal clear: We need to nail down the configuration details. What TLS version is being used? What cipher suites are supported, and how are they configured? What's the MTU? What are the underlying socket buffer sizes? I need to understand the environment to craft effective fuzzing campaigns. Let's find that config.

{
  "Expression": "config TLS",
  "PathPrefix": "net/tls/Kconfig"
}

{
  "Output": "net/tls/Kconfig-4-#\nnet/tls/Kconfig:5:config TLS\nnet/tls/Kconfig-6-\ttristate \"Transport Layer Security support\"\n--\nnet/tls/Kconfig-18-\nnet/tls/Kconfig:19:config TLS_DEVICE\nnet/tls/Kconfig-20-\tbool \"Transport Layer Security HW offload\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 3366
							output: 32
							thoughts: 31
						

Here's my summary, as though I'm thinking through this:

**Examining the TLS Configuration**

Okay, so the current configuration is flagged as using `TLS` and `TLS_DEVICE`. My first move is to dive straight into `net/tls/Kconfig`. This is the logical place to start digging deeper into the specifics of that `TLS_DEVICE` option. I need to understand what that particular flag is enabling and disabling within the TLS context. Time to pull up the Kconfig file and see what insights it offers. This should give me the core information needed to understand the implications of these settings.

{
  "File": "net/tls/Kconfig",
  "FirstLine": 1,
  "LineCount": 30
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\t#\n   3:\t# TLS configuration\n   4:\t#\n   5:\tconfig TLS\n   6:\t\ttristate \"Transport Layer Security support\"\n   7:\t\tdepends on INET\n   8:\t\tselect CRYPTO\n   9:\t\tselect CRYPTO_AES\n  10:\t\tselect CRYPTO_GCM\n  11:\t\tselect NET_SOCK_MSG\n  12:\t\tdefault n\n  13:\t\thelp\n  14:\t\tEnable kernel support for TLS protocol. This allows symmetric\n  15:\t\tencryption handling of the TLS protocol to be done in-kernel.\n  16:\t\n  17:\t\tIf unsure, say N.\n  18:\t\n  19:\tconfig TLS_DEVICE\n  20:\t\tbool \"Transport Layer Security HW offload\"\n  21:\t\tdepends on TLS\n  22:\t\tselect SKB_DECRYPTED\n  23:\t\tselect SOCK_VALIDATE_XMIT\n  24:\t\tselect SOCK_RX_QUEUE_MAPPING\n  25:\t\tdefault n\n  26:\t\thelp\n  27:\t\tEnable kernel support for HW offload of the TLS protocol.\n  28:\t\n  29:\t\tIf unsure, say N.\n"
}

gemini-3.1-pro-preview

null

null

							input: 3883
							output: 35
							thoughts: 122
						

**Focusing on TLS Device Operations**

Okay, so I'm looking at these configurations, `TLS` and `TLS_DEVICE`. My immediate thought is to zero in on specific functions within that context. The goal is to identify the critical operations. I initially thought `tls_device_sendmsg` and `tls_device_splice_eof` were the key areas to investigate. However, I need to consider that `tls_push_data` is static. Alright, that means `tls_device_sendmsg`, `tls_device_splice_eof` and `tls_device_push_pending_record` are the functions of interest. Hmm, wait. `tls_device_push_pending_record` is also static! Fine, let's go back and thoroughly examine `tls_device_sendmsg` and `tls_device_splice_eof`. That's where the relevant actions are likely happening.

{
  "Expression": "tls_device_sendmsg",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "Output": "net/tls/tls_device.c=421=static int tls_push_data(struct sock *sk,\n--\nnet/tls/tls_device.c-565-\nnet/tls/tls_device.c:566:int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\nnet/tls/tls_device.c-567-{\n"
}

gemini-3.1-pro-preview

null

null

							input: 4347
							output: 36
							thoughts: 13
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Analyzing `tls_device_splice_eof`**

Okay, time to dive into `tls_device_splice_eof`. This function likely handles the graceful end-of-file condition within a TLS connection, particularly when using a splice mechanism for data transfer. My initial thought is to confirm how this is handled, and what are the specific considerations? Am I seeing how the TLS layer interacts with the underlying socket or file descriptor? What's the error handling like in this specific path?

I'll be looking for how the EOF is signaled from the lower layers up. Is it a simple `read` returning 0, or is there some more nuanced TLS-specific signaling involved? I need to understand if the splice operation handles the closing sequence correctly (e.g., sending TLS close alerts, cleaning up resources). I'll want to see how this function integrates with the overall flow of the TLS connection teardown. What are the key points to assess in this function?

{
  "Expression": "tls_device_splice_eof",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "Output": "net/tls/tls_device.c=566=int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\n--\nnet/tls/tls_device.c-592-\nnet/tls/tls_device.c:593:void tls_device_splice_eof(struct socket *sock)\nnet/tls/tls_device.c-594-{\n"
}

gemini-3.1-pro-preview

null

null

							input: 4729
							output: 35
							thoughts: 12
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Analyzing `tls_device_sendpage` Function**

Okay, time to dissect `tls_device_sendpage`. I need to understand its behavior. First, I need to remind myself of the overall context. Is this related to a specific TLS implementation? What are the key assumptions baked into this design? I'm immediately interested in potential vulnerabilities, race conditions, and how it handles different error conditions. Does it perform appropriate input validation? Memory management is always a critical area to probe here, so I'll want to trace how it handles buffers, especially when dealing with potentially malicious or malformed input. What kind of hardware abstraction is it using? And how does it relate to DMA? The underlying crypto primitives also come into play; I need to quickly scan it to make sure they are used safely, and that there aren't any obvious side-channel leaks. I'll need to look at any interactions with interrupt handlers, and any potential for deadlock. Finally, I'll pay close attention to the error handling - are errors propagated correctly and, if so, how? I'll probably start with the most likely attack vectors, and then go in depth from there.

no matches

{
  "Expression": "tls_device_sendpage",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "error": "no matches"
}

gemini-3.1-pro-preview

null

null

							input: 5050
							output: 30
							thoughts: 24
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into tls_device_sendmsg**

Okay, time to get my hands dirty. Let's start by zeroing in on `tls_device_sendmsg` within `net/tls/tls_device.c`. That's where the rubber meets the road, as they say, for actual data transmission. I want to see exactly how TLS-encrypted data is being pushed out the door, so to speak. Specifically, I'm interested in the interplay between the TLS layer and the underlying network interface. I expect to find the standard socket calls in there, but I'm curious about the specific parameters being used, error handling, and whether there's anything particularly clever or potentially problematic going on, especially around buffer management or fragmentation. This is likely the best place to understand the interaction with the network driver and potential bottlenecks. Let's see if there are any obvious opportunities for optimization or potential security vulnerabilities lurking within.

{
  "Expression": "tls_device_sendmsg",
  "PathPrefix": "net/tls/"
}

{
  "Output": "net/tls/tls.h=169=int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,\n--\nnet/tls/tls.h-171-\nnet/tls/tls.h:172:int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);\nnet/tls/tls.h-173-void tls_device_splice_eof(struct socket *sock);\n--\nnet/tls/tls_device.c=421=static int tls_push_data(struct sock *sk,\n--\nnet/tls/tls_device.c-565-\nnet/tls/tls_device.c:566:int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\nnet/tls/tls_device.c-567-{\n--\nnet/tls/tls_main.c=998=static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],\n--\nnet/tls/tls_main.c-1022-\tprot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];\nnet/tls/tls_main.c:1023:\tprot[TLS_HW][TLS_BASE].sendmsg\t\t= tls_device_sendmsg;\nnet/tls/tls_main.c-1024-\tprot[TLS_HW][TLS_BASE].splice_eof\t= tls_device_splice_eof;\n--\nnet/tls/tls_main.c-1026-\tprot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];\nnet/tls/tls_main.c:1027:\tprot[TLS_HW][TLS_SW].sendmsg\t\t= tls_device_sendmsg;\nnet/tls/tls_main.c-1028-\tprot[TLS_HW][TLS_SW].splice_eof\t\t= tls_device_splice_eof;\n"
}

gemini-3.1-pro-preview

null

null

							input: 5820
							output: 121
							thoughts: 227
						

**My Assessment of the TLS Subsystem Modification**

Okay, so I've got this patch here and it looks like the entry points are `tls_device_sendmsg` and `tls_device_splice_eof`. The relevant configurations are `TLS` and `TLS_DEVICE`. The actual change itself is inside `tls_push_data`, which, as I suspected, is reachable through both of those entry points I just mentioned.

The meat of the change seems to be around how `more` is set to `true` when `MSG_MORE` is true. This is definitely a functional change in the TLS subsystem, impacting how fragmentation is handled when using hardware offload. Since this modifies the core logic and can be triggered by user space interaction through `sendmsg` or `splice`, it's definitely something that warrants a closer look and likely fuzzing to see what edge cases might be exposed.

Therefore, I'm marking this as `WorthFuzzing=true`. This modification to fragmentation behavior in `tls_push_data`, accessible via those critical symbols and configurations, needs to be thoroughly scrutinized.

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE"
  ],
  "FocusSymbols": [
    "tls_device_sendmsg",
    "tls_device_splice_eof"
  ],
  "Reasoning": "The patch modifies the fragmentation logic in `tls_push_data` for TLS hardware offload when `MSG_MORE` is used. This is a functional change in the TLS subsystem that can be triggered from userspace via `sendmsg` or `splice` on a TLS socket with hardware offload enabled.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE"
  ],
  "FocusSymbols": [
    "tls_device_sendmsg",
    "tls_device_splice_eof"
  ],
  "Reasoning": "The patch modifies the fragmentation logic in `tls_push_data` for TLS hardware offload when `MSG_MORE` is used. This is a functional change in the TLS subsystem that can be triggered from userspace via `sendmsg` or `splice` on a TLS socket with hardware offload enabled.",
  "WorthFuzzing": true
}

{
  "WorthFuzzing": true
}

null

best-expensive

null

{
  "KMSANReasoning": "The patch modifies the condition in `tls_push_data` to prevent leaving a TLS record open if its fragment count (`num_frags`) has reached `MAX_SKB_FRAGS - 1`. Prior to this patch, if `size == 0` and `MSG_MORE` was set, the code would break out of the loop and leave the record open, even if `num_frags` was already at the maximum allowed value. On the next call to `tls_push_data`, `tls_append_frag` could be called on this open record, which would increment `num_frags` beyond `MAX_SKB_FRAGS` and cause an out-of-bounds read and write on the `record-\u003efrags` array.\n\nThis is a classic array overflow / out-of-bounds access bug. KASAN is specifically designed to detect out-of-bounds accesses and will reliably catch this bug. There is no uninitialized memory usage or information leak to user space involved here. Therefore, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false
}

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.

For your convenience, here is the diff of the changes:
commit 89b4054378591fc8b2c520685443171bb9566d3a
Author: syz-cluster <triage@syzkaller.com>
Date:   Sun Aug 23 09:38:18 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 37bb06a8e8f5b..f11d0528fc431 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -531,7 +531,8 @@ static int tls_push_data(struct sock *sk,
 		if (!size) {
 last_record:
 			tls_push_record_flags = flags;
-			if (flags & MSG_MORE) {
+			if ((flags & MSG_MORE) &&
+			    record->num_frags < MAX_SKB_FRAGS - 1) {
 				more = true;
 				break;
 			}

gemini-3.1-pro-preview

null

null

							input: 1984
							output: 34
							thoughts: 292
						

**Analyzing a TLS Patch**

Okay, so I'm looking at a patch in `net/tls/tls_device.c`. It's tweaking the `tls_push_data` function, specifically how it handles `MSG_MORE` flags. My immediate thought is, this is probably a memory safety fix. They've added a check: `record->num_frags < MAX_SKB_FRAGS - 1`.

That `num_frags` field immediately grabs my attention. It strongly suggests a potential buffer overflow or out-of-bounds access within the fragment handling logic. If `num_frags` were to exceed `MAX_SKB_FRAGS`, we'd be looking at a likely KASAN-detectable bug, a read or write going beyond the allocated bounds of the `frags` array or a similar structure likely in `skb_shared_info`. It's a classic scenario. The patch is probably preventing us from incrementing `more = true` when there are more fragments than the system expects.

So, let's take a closer look at `tls_push_data` itself to confirm this hunch and get a better understanding of the context.

{
  "Expression": "tls_push_data",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "Output": "net/tls/tls_device.c=396=static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)\n--\nnet/tls/tls_device.c-420-\nnet/tls/tls_device.c:421:static int tls_push_data(struct sock *sk,\nnet/tls/tls_device.c-422-\t\t\t struct iov_iter *iter,\n--\nnet/tls/tls_device.c=566=int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\n--\nnet/tls/tls_device.c-583-\nnet/tls/tls_device.c:584:\trc = tls_push_data(sk, \u0026msg-\u003emsg_iter, size, msg-\u003emsg_flags,\nnet/tls/tls_device.c-585-\t\t\t   record_type);\n--\nnet/tls/tls_device.c=593=void tls_device_splice_eof(struct socket *sock)\n--\nnet/tls/tls_device.c-608-\t\tiov_iter_bvec(\u0026iter, ITER_SOURCE, NULL, 0, 0);\nnet/tls/tls_device.c:609:\t\ttls_push_data(sk, \u0026iter, 0, 0, TLS_RECORD_TYPE_DATA);\nnet/tls/tls_device.c-610-\t}\n--\nnet/tls/tls_device.c=676=static int tls_device_push_pending_record(struct sock *sk, int flags)\n--\nnet/tls/tls_device.c-680-\tiov_iter_kvec(\u0026iter, ITER_SOURCE, NULL, 0, 0);\nnet/tls/tls_device.c:681:\treturn tls_push_data(sk, \u0026iter, 0, flags, TLS_RECORD_TYPE_DATA);\nnet/tls/tls_device.c-682-}\n"
}

gemini-3.1-pro-preview

null

null

							input: 3072
							output: 38
							thoughts: 11
						

Okay, here's my interpretation of that thought process, assuming I'm deep in my domain of expertise:

**Diving into the `tls_push_data` Function**

Alright, time to crack open the code and take a look at `tls_push_data`. I'm specifically thinking about this function, so it must be central to something I'm focusing on right now. Perhaps it's involved in optimizing data delivery over TLS? Maybe I'm troubleshooting a performance bottleneck, investigating a potential security vulnerability related to how data is pushed, or simply trying to understand the nuances of the TLS implementation in this context. I'm probably forming hypotheses about its interactions with other key components: the TLS handshake, the underlying network I/O, perhaps even considerations about session resumption or pre-shared keys. I'm keen to grasp the purpose of this function and how it relates to my area of focus.

{
  "File": "net/tls/tls_device.c",
  "FirstLine": 421,
  "LineCount": 100
}

{
  "Contents": " 421:\tstatic int tls_push_data(struct sock *sk,\n 422:\t\t\t\t struct iov_iter *iter,\n 423:\t\t\t\t size_t size, int flags,\n 424:\t\t\t\t unsigned char record_type)\n 425:\t{\n 426:\t\tstruct tls_context *tls_ctx = tls_get_ctx(sk);\n 427:\t\tstruct tls_prot_info *prot = \u0026tls_ctx-\u003eprot_info;\n 428:\t\tstruct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);\n 429:\t\tstruct tls_record_info *record;\n 430:\t\tint tls_push_record_flags;\n 431:\t\tstruct page_frag *pfrag;\n 432:\t\tsize_t orig_size = size;\n 433:\t\tu32 max_open_record_len;\n 434:\t\tbool more = false;\n 435:\t\tbool done = false;\n 436:\t\tint copy, rc = 0;\n 437:\t\tlong timeo;\n 438:\t\n 439:\t\tif (flags \u0026\n 440:\t\t    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |\n 441:\t\t      MSG_SPLICE_PAGES | MSG_EOR))\n 442:\t\t\treturn -EOPNOTSUPP;\n 443:\t\n 444:\t\tif ((flags \u0026 (MSG_MORE | MSG_EOR)) == (MSG_MORE | MSG_EOR))\n 445:\t\t\treturn -EINVAL;\n 446:\t\n 447:\t\tif (unlikely(sk-\u003esk_err))\n 448:\t\t\treturn -sk-\u003esk_err;\n 449:\t\n 450:\t\tflags |= MSG_SENDPAGE_DECRYPTED;\n 451:\t\ttls_push_record_flags = flags | MSG_MORE;\n 452:\t\n 453:\t\ttimeo = sock_sndtimeo(sk, flags \u0026 MSG_DONTWAIT);\n 454:\t\tif (tls_is_partially_sent_record(tls_ctx)) {\n 455:\t\t\trc = tls_push_partial_record(sk, tls_ctx, flags);\n 456:\t\t\tif (rc \u003c 0)\n 457:\t\t\t\treturn rc;\n 458:\t\t}\n 459:\t\n 460:\t\tpfrag = sk_page_frag(sk);\n 461:\t\n 462:\t\t/* TLS_HEADER_SIZE is not counted as part of the TLS record, and\n 463:\t\t * we need to leave room for an authentication tag.\n 464:\t\t */\n 465:\t\tmax_open_record_len = tls_ctx-\u003etx_max_payload_len +\n 466:\t\t\t\t      prot-\u003eprepend_size;\n 467:\t\tdo {\n 468:\t\t\trc = tls_do_allocation(sk, ctx, pfrag, prot-\u003eprepend_size);\n 469:\t\t\tif (unlikely(rc)) {\n 470:\t\t\t\trc = sk_stream_wait_memory(sk, \u0026timeo);\n 471:\t\t\t\tif (!rc)\n 472:\t\t\t\t\tcontinue;\n 473:\t\n 474:\t\t\t\trecord = ctx-\u003eopen_record;\n 475:\t\t\t\tif (!record)\n 476:\t\t\t\t\tbreak;\n 477:\thandle_error:\n 478:\t\t\t\tif (record_type != TLS_RECORD_TYPE_DATA) {\n 479:\t\t\t\t\t/* avoid sending partial\n 480:\t\t\t\t\t * record with type !=\n 481:\t\t\t\t\t * application_data\n 482:\t\t\t\t\t */\n 483:\t\t\t\t\tsize = orig_size;\n 484:\t\t\t\t\tdestroy_record(record);\n 485:\t\t\t\t\tctx-\u003eopen_record = NULL;\n 486:\t\t\t\t} else if (record-\u003elen \u003e prot-\u003eprepend_size) {\n 487:\t\t\t\t\tgoto last_record;\n 488:\t\t\t\t}\n 489:\t\n 490:\t\t\t\tbreak;\n 491:\t\t\t}\n 492:\t\n 493:\t\t\trecord = ctx-\u003eopen_record;\n 494:\t\n 495:\t\t\tcopy = min_t(size_t, size, max_open_record_len - record-\u003elen);\n 496:\t\t\tif (copy \u0026\u0026 (flags \u0026 MSG_SPLICE_PAGES)) {\n 497:\t\t\t\tstruct page_frag zc_pfrag;\n 498:\t\t\t\tstruct page **pages = \u0026zc_pfrag.page;\n 499:\t\t\t\tsize_t off;\n 500:\t\n 501:\t\t\t\trc = iov_iter_extract_pages(iter, \u0026pages,\n 502:\t\t\t\t\t\t\t    copy, 1, 0, \u0026off);\n 503:\t\t\t\tif (rc \u003c= 0) {\n 504:\t\t\t\t\tif (rc == 0)\n 505:\t\t\t\t\t\trc = -EIO;\n 506:\t\t\t\t\tgoto handle_error;\n 507:\t\t\t\t}\n 508:\t\t\t\tcopy = rc;\n 509:\t\n 510:\t\t\t\tif (WARN_ON_ONCE(!sendpage_ok(zc_pfrag.page))) {\n 511:\t\t\t\t\tiov_iter_revert(iter, copy);\n 512:\t\t\t\t\trc = -EIO;\n 513:\t\t\t\t\tgoto handle_error;\n 514:\t\t\t\t}\n 515:\t\n 516:\t\t\t\tzc_pfrag.offset = off;\n 517:\t\t\t\tzc_pfrag.size = copy;\n 518:\t\t\t\ttls_append_frag(record, \u0026zc_pfrag, copy);\n 519:\t\t\t} else if (copy) {\n 520:\t\t\t\tcopy = min_t(size_t, copy, pfrag-\u003esize - pfrag-\u003eoffset);\n"
}

gemini-3.1-pro-preview

null

null

							input: 4824
							output: 38
							thoughts: 13
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person:

**Diving Deeper into tls\_push\_data**

Alright, time to dig into `tls_push_data`. I've got a good foundation in TLS/SSL, understand the general handshake process and the importance of things like session resumption, key exchange, and cipher suite selection. But this `tls_push_data` function... it piques my interest. I suspect it's related to optimizations, perhaps around proactively sending data to a client before it explicitly requests it, potentially using server push or a similar mechanism. I know the general concepts, but I'm eager to understand the *implementation* details. What are the specific considerations? Are there any security implications? How does it integrate with existing TLS flows? I want to see the nitty-gritty: the data structures involved, the exact placement in the TLS protocol, the error handling, and of course, how it interacts with the underlying transport layer. My goal is to grasp its functionality at a detailed level. Let's see what we can find.

{
  "File": "net/tls/tls_device.c",
  "FirstLine": 521,
  "LineCount": 100
}

{
  "Contents": " 521:\t\n 522:\t\t\t\trc = tls_device_copy_data(page_address(pfrag-\u003epage) +\n 523:\t\t\t\t\t\t\t  pfrag-\u003eoffset, copy,\n 524:\t\t\t\t\t\t\t  iter);\n 525:\t\t\t\tif (rc)\n 526:\t\t\t\t\tgoto handle_error;\n 527:\t\t\t\ttls_append_frag(record, pfrag, copy);\n 528:\t\t\t}\n 529:\t\n 530:\t\t\tsize -= copy;\n 531:\t\t\tif (!size) {\n 532:\tlast_record:\n 533:\t\t\t\ttls_push_record_flags = flags;\n 534:\t\t\t\tif ((flags \u0026 MSG_MORE) \u0026\u0026\n 535:\t\t\t\t    record-\u003enum_frags \u003c MAX_SKB_FRAGS - 1) {\n 536:\t\t\t\t\tmore = true;\n 537:\t\t\t\t\tbreak;\n 538:\t\t\t\t}\n 539:\t\n 540:\t\t\t\tdone = true;\n 541:\t\t\t}\n 542:\t\n 543:\t\t\tif (done || record-\u003elen \u003e= max_open_record_len ||\n 544:\t\t\t    (record-\u003enum_frags \u003e= MAX_SKB_FRAGS - 1)) {\n 545:\t\t\t\ttls_device_record_close(sk, tls_ctx, record,\n 546:\t\t\t\t\t\t\tpfrag, record_type);\n 547:\t\n 548:\t\t\t\trc = tls_push_record(sk,\n 549:\t\t\t\t\t\t     tls_ctx,\n 550:\t\t\t\t\t\t     ctx,\n 551:\t\t\t\t\t\t     record,\n 552:\t\t\t\t\t\t     tls_push_record_flags);\n 553:\t\t\t\tif (rc \u003c 0)\n 554:\t\t\t\t\tbreak;\n 555:\t\t\t}\n 556:\t\t} while (!done);\n 557:\t\n 558:\t\ttls_ctx-\u003epending_open_record_frags = more;\n 559:\t\n 560:\t\tif (orig_size - size \u003e 0)\n 561:\t\t\trc = orig_size - size;\n 562:\t\n 563:\t\treturn rc;\n 564:\t}\n 565:\t\n 566:\tint tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\n 567:\t{\n 568:\t\tunsigned char record_type = TLS_RECORD_TYPE_DATA;\n 569:\t\tstruct tls_context *tls_ctx = tls_get_ctx(sk);\n 570:\t\tint rc;\n 571:\t\n 572:\t\tif (!tls_ctx-\u003ezerocopy_sendfile)\n 573:\t\t\tmsg-\u003emsg_flags \u0026= ~MSG_SPLICE_PAGES;\n 574:\t\n 575:\t\tmutex_lock(\u0026tls_ctx-\u003etx_lock);\n 576:\t\tlock_sock(sk);\n 577:\t\n 578:\t\tif (unlikely(msg-\u003emsg_controllen)) {\n 579:\t\t\trc = tls_process_cmsg(sk, msg, \u0026record_type);\n 580:\t\t\tif (rc)\n 581:\t\t\t\tgoto out;\n 582:\t\t}\n 583:\t\n 584:\t\trc = tls_push_data(sk, \u0026msg-\u003emsg_iter, size, msg-\u003emsg_flags,\n 585:\t\t\t\t   record_type);\n 586:\t\n 587:\tout:\n 588:\t\trelease_sock(sk);\n 589:\t\tmutex_unlock(\u0026tls_ctx-\u003etx_lock);\n 590:\t\treturn rc;\n 591:\t}\n 592:\t\n 593:\tvoid tls_device_splice_eof(struct socket *sock)\n 594:\t{\n 595:\t\tstruct sock *sk = sock-\u003esk;\n 596:\t\tstruct tls_context *tls_ctx = tls_get_ctx(sk);\n 597:\t\tstruct iov_iter iter = {};\n 598:\t\n 599:\t\tif (!tls_is_partially_sent_record(tls_ctx) \u0026\u0026\n 600:\t\t    !tls_is_pending_open_record(tls_ctx))\n 601:\t\t\treturn;\n 602:\t\n 603:\t\tmutex_lock(\u0026tls_ctx-\u003etx_lock);\n 604:\t\tlock_sock(sk);\n 605:\t\n 606:\t\tif (tls_is_partially_sent_record(tls_ctx) ||\n 607:\t\t    tls_is_pending_open_record(tls_ctx)) {\n 608:\t\t\tiov_iter_bvec(\u0026iter, ITER_SOURCE, NULL, 0, 0);\n 609:\t\t\ttls_push_data(sk, \u0026iter, 0, 0, TLS_RECORD_TYPE_DATA);\n 610:\t\t}\n 611:\t\n 612:\t\trelease_sock(sk);\n 613:\t\tmutex_unlock(\u0026tls_ctx-\u003etx_lock);\n 614:\t}\n 615:\t\n 616:\tstruct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,\n 617:\t\t\t\t\t       u32 seq, u64 *p_record_sn)\n 618:\t{\n 619:\t\tu64 record_sn = context-\u003ehint_record_sn;\n 620:\t\tstruct tls_record_info *info, *last;\n"
}

gemini-3.1-pro-preview

null

null

							input: 6560
							output: 34
							thoughts: 464
						

**Analyzing the Fragment Limit in TLS Record Handling**

Okay, so I'm looking at this patch and trying to understand the implications of this `record->num_frags < MAX_SKB_FRAGS - 1` check. My initial thought was, "Why are we breaking the loop if `more` is set and the fragment count is *below* the limit?" If `more` is true, indicating there's more data coming, we're skipping `tls_push_record` to keep the record open. Seems logical.

But then I realized, what happens if `num_frags` *is* already at `MAX_SKB_FRAGS - 1`? We *shouldn't* leave it open if we can't add more fragments. Digging deeper, I see a crucial conditional block:

```c
		if (done || record->len >= max_open_record_len ||
		    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
			tls_device_record_close(sk, tls_ctx, record,
						pfrag, record_type);

			rc = tls_push_record(sk,
					     tls_ctx,
					     ctx,
					     record,
					     tls_push_record_flags);
```

Ah, right! If `num_frags` *is* at the limit, the code closes and pushes the record anyway. That makes sense. However, I recall a previous scenario where, if the `size` was 0 and `MSG_MORE` was set, we'd set `more = true` and break, skipping the push. This is where it gets interesting...

If that happens, and `num_frags` was at the limit, on the *next* call to `tls_push_data`, we'd try to append to the already-full record. This looks like a recipe for either a failure to append (because there's no space) or, worse, an out-of-bounds memory access!

Okay, I see the `tls_ctx->pending_open_record_frags = more;` bit. That's how we're tracking the 'more' state. The next `sendmsg` will then call `tls_push_data`, which seems to be the entry point for handling this next chunk. Let's see...

```c
		rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
```

`tls_do_allocation` is key here. It must either allocate a new record or re-use the open one, which is determined by `tls_ctx->pending_open_record_frags`. I need to look closer at `tls_do_allocation` to fully grasp the behavior and if my concerns are justified.

{
  "Expression": "tls_do_allocation",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "Output": "net/tls/tls_device.c=342=static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,\n--\nnet/tls/tls_device.c-365-\nnet/tls/tls_device.c:366:static int tls_do_allocation(struct sock *sk,\nnet/tls/tls_device.c-367-\t\t\t     struct tls_offload_context_tx *offload_ctx,\n--\nnet/tls/tls_device.c=421=static int tls_push_data(struct sock *sk,\n--\nnet/tls/tls_device.c-467-\tdo {\nnet/tls/tls_device.c:468:\t\trc = tls_do_allocation(sk, ctx, pfrag, prot-\u003eprepend_size);\nnet/tls/tls_device.c-469-\t\tif (unlikely(rc)) {\n"
}

gemini-3.1-pro-preview

null

null

							input: 7920
							output: 37
							thoughts: 11
						

Okay, here we go...

**Delving into `tls_do_allocation`**

Alright, let's dive into this `tls_do_allocation` function. Seems like it's a critical piece for Thread-Local Storage. I need to understand this thoroughly, especially given my background in [User's Field of Expertise - e.g., operating system internals, compiler design, low-level memory management]. I'm immediately looking for the core allocation strategy. Is it dynamic? Static? A hybrid approach? What are the key data structures involved – are we talking about per-thread control blocks, bitmaps, page tables, or something else entirely?

I'm also curious about the concurrency aspects. How does this handle multiple threads requesting TLS memory simultaneously? Is there any locking involved, and if so, what's the granularity? Fine-grained? Global? The potential for contention is high in this kind of critical section. I need to see how they've mitigated that.

Furthermore, I'm expecting some level of optimization. Is this code performance-sensitive? Are they employing tricks like pre-allocation, lazy allocation, or perhaps alignment strategies to minimize overhead? Let's check how they manage the virtual address space and if any specific memory protection techniques are leveraged, given that we are dealing with a critical security area for each thread.

Finally, I'll be looking at error handling. What happens when the allocation fails – insufficient memory, address space exhaustion, etc.? How gracefully does it handle these scenarios, and what mechanisms are used for reporting errors to the calling thread or process? Let's see how resilient this design is to adverse conditions.

{
  "File": "net/tls/tls_device.c",
  "FirstLine": 366,
  "LineCount": 50
}

{
  "Contents": " 366:\tstatic int tls_do_allocation(struct sock *sk,\n 367:\t\t\t\t     struct tls_offload_context_tx *offload_ctx,\n 368:\t\t\t\t     struct page_frag *pfrag,\n 369:\t\t\t\t     size_t prepend_size)\n 370:\t{\n 371:\t\tint ret;\n 372:\t\n 373:\t\tif (!offload_ctx-\u003eopen_record) {\n 374:\t\t\tif (unlikely(!skb_page_frag_refill(prepend_size, pfrag,\n 375:\t\t\t\t\t\t\t   sk-\u003esk_allocation))) {\n 376:\t\t\t\tif (!sk-\u003esk_bypass_prot_mem)\n 377:\t\t\t\t\tREAD_ONCE(sk-\u003esk_prot)-\u003eenter_memory_pressure(sk);\n 378:\t\t\t\tsk_stream_moderate_sndbuf(sk);\n 379:\t\t\t\treturn -ENOMEM;\n 380:\t\t\t}\n 381:\t\n 382:\t\t\tret = tls_create_new_record(offload_ctx, pfrag, prepend_size);\n 383:\t\t\tif (ret)\n 384:\t\t\t\treturn ret;\n 385:\t\n 386:\t\t\tif (pfrag-\u003esize \u003e pfrag-\u003eoffset)\n 387:\t\t\t\treturn 0;\n 388:\t\t}\n 389:\t\n 390:\t\tif (!sk_page_frag_refill(sk, pfrag))\n 391:\t\t\treturn -ENOMEM;\n 392:\t\n 393:\t\treturn 0;\n 394:\t}\n 395:\t\n 396:\tstatic int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)\n 397:\t{\n 398:\t\tsize_t pre_copy, nocache;\n 399:\t\n 400:\t\tpre_copy = ~((unsigned long)addr - 1) \u0026 (SMP_CACHE_BYTES - 1);\n 401:\t\tif (pre_copy) {\n 402:\t\t\tpre_copy = min(pre_copy, bytes);\n 403:\t\t\tif (copy_from_iter(addr, pre_copy, i) != pre_copy)\n 404:\t\t\t\treturn -EFAULT;\n 405:\t\t\tbytes -= pre_copy;\n 406:\t\t\taddr += pre_copy;\n 407:\t\t}\n 408:\t\n 409:\t\tnocache = round_down(bytes, SMP_CACHE_BYTES);\n 410:\t\tif (copy_from_iter_nocache(addr, nocache, i) != nocache)\n 411:\t\t\treturn -EFAULT;\n 412:\t\tbytes -= nocache;\n 413:\t\taddr += nocache;\n 414:\t\n 415:\t\tif (bytes \u0026\u0026 copy_from_iter(addr, bytes, i) != bytes)\n"
}

gemini-3.1-pro-preview

null

null

							input: 9081
							output: 34
							thoughts: 261
						

**My Analysis of the TLS Data Handling Logic**

Okay, so if `more` is true, `tls_push_data` wisely bails out early, skipping the record push. Smart. That means the next time `tls_do_allocation` is called, it finds that the `offload_ctx->open_record` isn't null. Good, because that tells it to just replenish the fragment buffer, `pfrag`, which is probably holding some partially-filled record data.

Now, it gets interesting. We're in the critical `tls_do_allocation` section where we actually *do* something with the data. It picks up the `record` from `ctx->open_record`. Then we've got a copy calculation: `copy = min_t(size_t, size, max_open_record_len - record->len)`. Basically, it's figuring out how much data it can cram into the current record, making sure it doesn't overflow `max_open_record_len`. And here's where it splits.

If `MSG_SPLICE_PAGES` is set, we use zero-copy, going directly into `tls_append_frag` with zero-copy pages. But if not, we get a copy! So the `copy` is now re-limited by the space in our current fragment buffer. Then we call `tls_device_copy_data`. That's where the actual data transfer happens, moving data from the iterator to the device buffer. Any error here means a `goto handle_error`.  After the device copy, we go to `tls_append_frag` regardless.

Now I need to understand what `tls_append_frag` is doing in detail. That's the core of how this all comes together.

{
  "Expression": "tls_append_frag",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "Output": "net/tls/tls_device.c=232=static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,\n--\nnet/tls/tls_device.c-256-\nnet/tls/tls_device.c:257:static void tls_append_frag(struct tls_record_info *record,\nnet/tls/tls_device.c-258-\t\t\t    struct page_frag *pfrag,\n--\nnet/tls/tls_device.c=313=static void tls_device_record_close(struct sock *sk,\n--\nnet/tls/tls_device.c-333-\t}\nnet/tls/tls_device.c:334:\ttls_append_frag(record, pfrag, prot-\u003etag_size);\nnet/tls/tls_device.c-335-\n--\nnet/tls/tls_device.c=421=static int tls_push_data(struct sock *sk,\n--\nnet/tls/tls_device.c-517-\t\t\tzc_pfrag.size = copy;\nnet/tls/tls_device.c:518:\t\t\ttls_append_frag(record, \u0026zc_pfrag, copy);\nnet/tls/tls_device.c-519-\t\t} else if (copy) {\n--\nnet/tls/tls_device.c-526-\t\t\t\tgoto handle_error;\nnet/tls/tls_device.c:527:\t\t\ttls_append_frag(record, pfrag, copy);\nnet/tls/tls_device.c-528-\t\t}\n"
}

gemini-3.1-pro-preview

null

null

							input: 10166
							output: 37
							thoughts: 11
						

Okay, here's my interpretation of that thought process, tailored for an expert audience:

**Analyzing `tls_append_frag`**

Alright, let's dive into `tls_append_frag`. I'm immediately interested in what this function is doing at a fundamental level. Based on the name, my initial assumption is that it's handling the fragmentation of Transport Layer Security (TLS) records. We're obviously in a context where a TLS connection is established, and we need to deal with potentially oversized data chunks. I'm curious about the specific scenarios where this function comes into play. Is it purely for TCP over TLS, or does it apply to DTLS as well? And what's the underlying data structure it's manipulating? Are we dealing with a buffer pool, chained buffers, or something else entirely? The efficiency and thread-safety of this fragmenting process are immediately top-of-mind. I want to see how this function handles potential race conditions, especially if it’s dealing with concurrent reads and writes on the same TLS connection. I'm also looking for any subtle performance optimizations. Does it pre-calculate fragment sizes? Does it use a sliding window approach for congestion control? This function is key to the overall performance of TLS, so I expect to scrutinize it thoroughly, ensuring it handles all the edge cases correctly and efficiently.

{
  "File": "net/tls/tls_device.c",
  "FirstLine": 257,
  "LineCount": 50
}

{
  "Contents": " 257:\tstatic void tls_append_frag(struct tls_record_info *record,\n 258:\t\t\t\t    struct page_frag *pfrag,\n 259:\t\t\t\t    int size)\n 260:\t{\n 261:\t\tskb_frag_t *frag;\n 262:\t\n 263:\t\tfrag = \u0026record-\u003efrags[record-\u003enum_frags - 1];\n 264:\t\tif (skb_frag_page(frag) == pfrag-\u003epage \u0026\u0026\n 265:\t\t    skb_frag_off(frag) + skb_frag_size(frag) == pfrag-\u003eoffset) {\n 266:\t\t\tskb_frag_size_add(frag, size);\n 267:\t\t} else {\n 268:\t\t\t++frag;\n 269:\t\t\tskb_frag_fill_page_desc(frag, pfrag-\u003epage, pfrag-\u003eoffset,\n 270:\t\t\t\t\t\tsize);\n 271:\t\t\t++record-\u003enum_frags;\n 272:\t\t\tget_page(pfrag-\u003epage);\n 273:\t\t}\n 274:\t\n 275:\t\tpfrag-\u003eoffset += size;\n 276:\t\trecord-\u003elen += size;\n 277:\t}\n 278:\t\n 279:\tstatic int tls_push_record(struct sock *sk,\n 280:\t\t\t\t   struct tls_context *ctx,\n 281:\t\t\t\t   struct tls_offload_context_tx *offload_ctx,\n 282:\t\t\t\t   struct tls_record_info *record,\n 283:\t\t\t\t   int flags)\n 284:\t{\n 285:\t\tstruct tls_prot_info *prot = \u0026ctx-\u003eprot_info;\n 286:\t\tstruct tcp_sock *tp = tcp_sk(sk);\n 287:\t\tskb_frag_t *frag;\n 288:\t\tint i;\n 289:\t\n 290:\t\trecord-\u003eend_seq = tp-\u003ewrite_seq + record-\u003elen;\n 291:\t\tlist_add_tail_rcu(\u0026record-\u003elist, \u0026offload_ctx-\u003erecords_list);\n 292:\t\toffload_ctx-\u003eopen_record = NULL;\n 293:\t\n 294:\t\tif (test_bit(TLS_TX_SYNC_SCHED, \u0026ctx-\u003eflags))\n 295:\t\t\ttls_device_resync_tx(sk, ctx, tp-\u003ewrite_seq);\n 296:\t\n 297:\t\ttls_advance_record_sn(sk, prot, \u0026ctx-\u003etx);\n 298:\t\n 299:\t\tfor (i = 0; i \u003c record-\u003enum_frags; i++) {\n 300:\t\t\tfrag = \u0026record-\u003efrags[i];\n 301:\t\t\tsg_unmark_end(\u0026offload_ctx-\u003esg_tx_data[i]);\n 302:\t\t\tsg_set_page(\u0026offload_ctx-\u003esg_tx_data[i], skb_frag_page(frag),\n 303:\t\t\t\t    skb_frag_size(frag), skb_frag_off(frag));\n 304:\t\t\tsk_mem_charge(sk, skb_frag_size(frag));\n 305:\t\t\tget_page(skb_frag_page(frag));\n 306:\t\t}\n"
}

gemini-3.1-pro-preview

null

null

							input: 11363
							output: 34
							thoughts: 141
						

**Out-of-Bounds Access in `tls_append_frag`?**

Okay, so I'm looking at this `tls_append_frag` function, and my immediate concern is this line: `record->frags[record->num_frags - 1]`. That's where it's accessing the fragments, and I see a potential issue. If the current fragment doesn't match the expected page, it increments `frag` and then increments `record->num_frags`. My Spidey sense is tingling because if `record->num_frags` *was* already at `MAX_SKB_FRAGS`, this would mean the code would try to write to `record->frags[MAX_SKB_FRAGS]`, right? That's definitely out of bounds.

Wait a second... am I correct in assuming `record->frags` is actually an array with `MAX_SKB_FRAGS` elements? I need to confirm that. Let me quickly double-check the definition of `struct tls_record_info` to make sure my assumptions are correct. I need to be sure the array size is properly declared, and also to ensure the data structure layout is as I think it is. I'm hoping I can find the answer quickly and confirm or refute this potential bug.

{
  "Expression": "struct tls_record_info \\{",
  "PathPrefix": "include/net/tls.h"
}

{
  "Output": "include/net/tls.h=131=struct tls_sw_context_rx {\n--\ninclude/net/tls.h-149-\ninclude/net/tls.h:150:struct tls_record_info {\ninclude/net/tls.h-151-\tstruct list_head list;\n"
}

gemini-3.1-pro-preview

null

null

							input: 11911
							output: 35
							thoughts: 12
						

Here's a first-person summary, assuming you're an expert and familiar with TLS:

**Diving into `struct tls_record_info`**

Alright, let's get into the nitty-gritty. I'm taking a look at this `struct tls_record_info`. Right off the bat, I'm expecting this to be the central data structure holding all the critical metadata about a TLS record. I need to understand how the lower layers are structured. I imagine it encapsulates information related to the record type – is this a handshake message, application data, alert, or change cipher spec? It’ll undoubtedly track the length of the payload, likely as a 16-bit or 32-bit integer, depending on the maximum record size we're dealing with. Knowing the length is paramount for proper parsing and framing. Then, of course, the version; which version of TLS are we communicating over? I'll be looking for fields representing the major and minor TLS versions, because different versions bring different security features. The record content – a pointer to the data itself – is going to be important too. I wonder if there’s an associated buffer management mechanism integrated. It's likely that a structure like this would include the record's sequence number to ensure the order of delivery and prevent replay attacks. I'm also curious about any potential flags or status bits related to fragmentation, padding, or compression that could be included. Essentially, I'm expecting this structure to be the fundamental unit of information for a TLS record on the wire. I hope it's well-designed and covers all the bases for robust parsing and security processing at the record layer. Let's see how they've defined it...

{
  "File": "include/net/tls.h",
  "FirstLine": 150,
  "LineCount": 20
}

{
  "Contents": " 150:\tstruct tls_record_info {\n 151:\t\tstruct list_head list;\n 152:\t\tu32 end_seq;\n 153:\t\tint len;\n 154:\t\tint num_frags;\n 155:\t\tskb_frag_t frags[MAX_SKB_FRAGS];\n 156:\t};\n 157:\t\n 158:\t#define TLS_DRIVER_STATE_SIZE_TX\t16\n 159:\tstruct tls_offload_context_tx {\n 160:\t\tstruct crypto_aead *aead_send;\n 161:\t\tspinlock_t lock;\t/* protects records list */\n 162:\t\tstruct list_head records_list;\n 163:\t\tstruct tls_record_info *open_record;\n 164:\t\tstruct tls_record_info *retransmit_hint;\n 165:\t\tu64 hint_record_sn;\n 166:\t\tu64 unacked_record_sn;\n 167:\t\n 168:\t\tstruct scatterlist sg_tx_data[MAX_SKB_FRAGS];\n 169:\t\tvoid (*sk_destruct)(struct sock *sk);\n"
}

gemini-3.1-pro-preview

null

null

							input: 12647
							output: 36
							thoughts: 1126
						

**Analyzing a Potential Out-of-Bounds Write in `tls_push_data`**

Okay, so `frags` is definitely an array with `MAX_SKB_FRAGS` elements. My concern is that `tls_append_frag` *could* be writing out of bounds if `record->num_frags` hits `MAX_SKB_FRAGS`. Let's step through this.

`tls_push_data` has a check to close the record: `if (done || record->len >= max_open_record_len || (record->num_frags >= MAX_SKB_FRAGS - 1))`.  It closes the record if `num_frags` is at `MAX_SKB_FRAGS - 1` or greater.

Here's the problem: The original code had a flaw. It could break out of a loop prematurely if `size == 0` and `flags` included `MSG_MORE`. Specifically, the code was breaking *before* the check that would close the record. That means if the record wasn't closed, it could be left open with `num_frags` at `MAX_SKB_FRAGS - 1`.

Next time, the function will try to append to that open record, and the `tls_append_frag` function would increment the `num_frags` counter. I was worried for a moment, thinking if `num_frags` was already at `MAX_SKB_FRAGS - 1`, that increment would push it out of bounds... but not quite.

`tls_append_frag` accesses the `frags` array based on the current `num_frags` value. If `num_frags` is `MAX_SKB_FRAGS - 1`, the access *within* the function itself is actually fine - it gets `frag = &record->frags[record->num_frags - 1];`. But here's where it gets interesting... The function can increment both the pointer and the `num_frags`.

If `num_frags` *is* `MAX_SKB_FRAGS - 1`, and the code *needs* to append a new fragment, then after incrementing `num_frags`, the value is now `MAX_SKB_FRAGS`, which *is* out of bounds. The key is that `tls_push_data` left the record open with `num_frags` at `MAX_SKB_FRAGS - 1`, and the next call to `tls_push_data` triggered the increment to `MAX_SKB_FRAGS`!  That means when `tls_append_frag` is called again it will write to `frags[MAX_SKB_FRAGS]`.

The vulnerability is a classic out-of-bounds write on the `frags` array. Thankfully, KASAN should have no problem detecting this. The question is, is there any possibility of information leakage here? No, this is writing *out of bounds* to `record->frags`, which is part of the `struct tls_record_info` allocated via `kmalloc` or similar by `tls_create_new_record`. I think we have our smoking gun, time to submit a patch!

{
  "Expression": "tls_create_new_record",
  "PathPrefix": "net/tls/tls_device.c"
}

{
  "Output": "net/tls/tls_device.c=313=static void tls_device_record_close(struct sock *sk,\n--\nnet/tls/tls_device.c-341-\nnet/tls/tls_device.c:342:static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,\nnet/tls/tls_device.c-343-\t\t\t\t struct page_frag *pfrag,\n--\nnet/tls/tls_device.c=366=static int tls_do_allocation(struct sock *sk,\n--\nnet/tls/tls_device.c-381-\nnet/tls/tls_device.c:382:\t\tret = tls_create_new_record(offload_ctx, pfrag, prepend_size);\nnet/tls/tls_device.c-383-\t\tif (ret)\n"
}

gemini-3.1-pro-preview

null

null

							input: 14760
							output: 37
							thoughts: 13
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into `tls_create_new_record`**

Okay, let's zero in on `tls_create_new_record`. I need to refresh my understanding of its role in the TLS handshake and record protocol, and make sure my assumptions are spot on. I want to quickly evaluate its core function, especially regarding how it handles the generation and inclusion of sequence numbers and the management of cipher states. Is it correctly handling the potential for fragmentation? Does it account for padding in the way I would expect, especially in the context of specific cipher suites and versions? I'll probably start by quickly tracing its call flow and checking its inputs to confirm my assumptions around the record's header, data length, and the key materials that are used during this operation. I'll need to know whether it properly updates the cipher state, to allow for the generation of the correct MAC or AEAD tag. Specifically, I'm thinking about the IV generation and the counter increment, depending on what TLS version and cipher suite is in use. I also want to see the error-handling paths and how it manages potential issues like buffer overflows. This is where the devil can be hiding! In short, I'm trying to mentally map out its role in a complete record transmission.

{
  "File": "net/tls/tls_device.c",
  "FirstLine": 342,
  "LineCount": 20
}

{
  "Contents": " 342:\tstatic int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,\n 343:\t\t\t\t\t struct page_frag *pfrag,\n 344:\t\t\t\t\t size_t prepend_size)\n 345:\t{\n 346:\t\tstruct tls_record_info *record;\n 347:\t\tskb_frag_t *frag;\n 348:\t\n 349:\t\trecord = kmalloc_obj(*record);\n 350:\t\tif (!record)\n 351:\t\t\treturn -ENOMEM;\n 352:\t\n 353:\t\tfrag = \u0026record-\u003efrags[0];\n 354:\t\tskb_frag_fill_page_desc(frag, pfrag-\u003epage, pfrag-\u003eoffset,\n 355:\t\t\t\t\tprepend_size);\n 356:\t\n 357:\t\tget_page(pfrag-\u003epage);\n 358:\t\tpfrag-\u003eoffset += prepend_size;\n 359:\t\n 360:\t\trecord-\u003enum_frags = 1;\n 361:\t\trecord-\u003elen = prepend_size;\n"
}

gemini-3.1-pro-preview

null

null

							input: 15394
							output: 24
							thoughts: 39
						

Okay, here's my interpretation of that thought process, assuming I'm the expert and considering my own internal monologue:

**Investigating `kmalloc_obj`**

Alright, that `kmalloc_obj`... that's probably a macro, and a common one at that. My gut says it's just a shorthand for `kmalloc`, likely allocating space for a struct, judging by the name `obj` and the implied pointer dereference. The `sizeof(*record)` bit makes perfect sense – allocating enough memory to hold an instance of whatever type `record` is. And `GFP_KERNEL` is the standard kernel allocation flag. This is all pretty textbook.

But, you know me, I don't trust assumptions. Let's not skip any steps. I'm going to quickly verify that, just to be sure. I'll need to double check that macro definition, it could be doing something unexpected, even if it's unlikely. Time to look it up. No shortcuts here!

{
  "Expression": "kmalloc_obj",
  "PathPrefix": ""
}

{
  "Output": "\nFull output is too long, showing 500 out of 15550 lines.\nUse more precise expression if possible.\n\nDocumentation/RCU/Design/Requirements/Requirements.rst=203=non-\\ ``NULL``, locklessly accessing the ``-\u003ea`` and ``-\u003eb`` fields.\n--\nDocumentation/RCU/Design/Requirements/Requirements.rst-208-       2 {\nDocumentation/RCU/Design/Requirements/Requirements.rst:209:       3   p = kmalloc_obj(*p);\nDocumentation/RCU/Design/Requirements/Requirements.rst-210-       4   if (!p)\n--\nDocumentation/RCU/Design/Requirements/Requirements.rst=225=their rights to reorder this code as follows:\n--\nDocumentation/RCU/Design/Requirements/Requirements.rst-230-       2 {\nDocumentation/RCU/Design/Requirements/Requirements.rst:231:       3   p = kmalloc_obj(*p);\nDocumentation/RCU/Design/Requirements/Requirements.rst-232-       4   if (!p)\n--\nDocumentation/RCU/Design/Requirements/Requirements.rst=261=shows an example of insertion:\n--\nDocumentation/RCU/Design/Requirements/Requirements.rst-266-       2 {\nDocumentation/RCU/Design/Requirements/Requirements.rst:267:       3   p = kmalloc_obj(*p);\nDocumentation/RCU/Design/Requirements/Requirements.rst-268-       4   if (!p)\n--\nDocumentation/RCU/listRCU.rst=267=The RCU version of audit_upd_rule() is as follows::\n--\nDocumentation/RCU/listRCU.rst-278-\t\t\tif (!audit_compare_rule(rule, \u0026e-\u003erule)) {\nDocumentation/RCU/listRCU.rst:279:\t\t\t\tne = kmalloc_obj(*entry, GFP_ATOMIC);\nDocumentation/RCU/listRCU.rst-280-\t\t\t\tif (ne == NULL)\n--\nDocumentation/RCU/whatisRCU.rst=441=uses of RCU may be found in listRCU.rst and NMI-RCU.rst.\n--\nDocumentation/RCU/whatisRCU.rst-470-\nDocumentation/RCU/whatisRCU.rst:471:\t\tnew_fp = kmalloc_obj(*new_fp);\nDocumentation/RCU/whatisRCU.rst-472-\t\tspin_lock(\u0026foo_mutex);\n--\nDocumentation/RCU/whatisRCU.rst=553=The foo_update_a() function might then be written as follows::\n--\nDocumentation/RCU/whatisRCU.rst-572-\nDocumentation/RCU/whatisRCU.rst:573:\t\tnew_fp = kmalloc_obj(*new_fp);\nDocumentation/RCU/whatisRCU.rst-574-\t\tspin_lock(\u0026foo_mutex);\n--\nDocumentation/core-api/kref.rst=39=kref_init as so::\n--\nDocumentation/core-api/kref.rst-42-\nDocumentation/core-api/kref.rst:43:     data = kmalloc_obj(*data);\nDocumentation/core-api/kref.rst-44-     if (!data)\n--\nDocumentation/core-api/kref.rst=81=thread to process::\n--\nDocumentation/core-api/kref.rst-102-\tstruct task_struct *task;\nDocumentation/core-api/kref.rst:103:\tdata = kmalloc_obj(*data);\nDocumentation/core-api/kref.rst-104-\tif (!data)\n--\nDocumentation/kernel-hacking/locking.rst=383=to protect the cache and all the objects within it. Here's the code::\n--\nDocumentation/kernel-hacking/locking.rst-444-\nDocumentation/kernel-hacking/locking.rst:445:            if ((obj = kmalloc_obj(*obj)) == NULL)\nDocumentation/kernel-hacking/locking.rst-446-                    return -ENOMEM;\n--\nDocumentation/kernel-hacking/locking.rst=499=which are taken away, and the ``+`` are lines which are added.\n--\nDocumentation/kernel-hacking/locking.rst-519-\nDocumentation/kernel-hacking/locking.rst:520:             if ((obj = kmalloc_obj(*obj)) == NULL)\nDocumentation/kernel-hacking/locking.rst-521-                     return -ENOMEM;\n--\nDocumentation/locking/locktypes.rst=498=works perfectly::\n--\nDocumentation/locking/locktypes.rst-500-  raw_spin_lock(\u0026lock);\nDocumentation/locking/locktypes.rst:501:  p = kmalloc_obj(*p, GFP_ATOMIC);\nDocumentation/locking/locktypes.rst-502-\n--\nDocumentation/locking/locktypes.rst=507=preemption on PREEMPT_RT kernels::\n--\nDocumentation/locking/locktypes.rst-509-  spin_lock(\u0026lock);\nDocumentation/locking/locktypes.rst:510:  p = kmalloc_obj(*p, GFP_ATOMIC);\nDocumentation/locking/locktypes.rst-511-\n--\nDocumentation/process/coding-style.rst=938=The kernel provides the following general purpose memory allocators:\nDocumentation/process/coding-style.rst:939:kmalloc(), kzalloc(), kmalloc_objs(), kzalloc_objs(), vmalloc(), and\nDocumentation/process/coding-style.rst-940-vzalloc().  Please refer to the API documentation for further information\n--\nDocumentation/process/coding-style.rst=944=The preferred form for passing a size of a struct is the following:\n--\nDocumentation/process/coding-style.rst-947-\nDocumentation/process/coding-style.rst:948:\tp = kmalloc_obj(*p, ...);\nDocumentation/process/coding-style.rst-949-\n--\nDocumentation/process/coding-style.rst=958=The preferred form for allocating an array is the following:\n--\nDocumentation/process/coding-style.rst-961-\nDocumentation/process/coding-style.rst:962:\tp = kmalloc_objs(*p, n, ...);\nDocumentation/process/coding-style.rst-963-\n--\nDocumentation/process/deprecated.rst=386=may help with alignment, wrap-around, or additional hardening. The\nDocumentation/process/deprecated.rst:387:kmalloc_obj()-family of macros provide this introspection, which can be\nDocumentation/process/deprecated.rst-388-used for the common code patterns for single, array, and flexible object\n--\nDocumentation/process/deprecated.rst=398=become, respectively::\nDocumentation/process/deprecated.rst-399-\nDocumentation/process/deprecated.rst:400:\tptr = kmalloc_obj(*ptr [, gfp] );\nDocumentation/process/deprecated.rst-401-\tptr = kzalloc_obj(*ptr [, gfp] );\nDocumentation/process/deprecated.rst:402:\tptr = kmalloc_objs(*ptr, count [, gfp] );\nDocumentation/process/deprecated.rst-403-\tptr = kzalloc_objs(*ptr, count [, gfp] );\nDocumentation/process/deprecated.rst-404-\tptr = kmalloc_flex(*ptr, flex_member, count [, gfp] );\nDocumentation/process/deprecated.rst:405:\t__auto_type ptr = kmalloc_obj(struct foo [, gfp] );\nDocumentation/process/deprecated.rst-406-\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=1734=callback::\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-1739-          ....\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:1740:          data = kmalloc_obj(*data);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-1741-          substream-\u003eruntime-\u003eprivate_data = data;\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=3302=destructor function is set in the ``private_free`` field::\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3303-\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:3304:  struct mydata *p = kmalloc_obj(*p);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3305-  hw-\u003eprivate_data = p;\n--\nDocumentation/spi/spi-summary.rst=242=And SOC-specific utility code might look something like::\n--\nDocumentation/spi/spi-summary.rst-251-\nDocumentation/spi/spi-summary.rst:252:\t\tpdata2 = kmalloc_obj(*pdata2);\nDocumentation/spi/spi-summary.rst-253-\t\t*pdata2 = pdata;\n--\nDocumentation/translations/it_IT/kernel-hacking/locking.rst=403=e tutti gli oggetti che contiene. Ecco il codice::\n--\nDocumentation/translations/it_IT/kernel-hacking/locking.rst-464-\nDocumentation/translations/it_IT/kernel-hacking/locking.rst:465:            if ((obj = kmalloc_obj(*obj)) == NULL)\nDocumentation/translations/it_IT/kernel-hacking/locking.rst-466-                    return -ENOMEM;\n--\nDocumentation/translations/it_IT/kernel-hacking/locking.rst=519=sono quelle rimosse, mentre quelle ``+`` sono quelle aggiunte.\n--\nDocumentation/translations/it_IT/kernel-hacking/locking.rst-539-\nDocumentation/translations/it_IT/kernel-hacking/locking.rst:540:             if ((obj = kmalloc_obj(*obj)) == NULL)\nDocumentation/translations/it_IT/kernel-hacking/locking.rst-541-                     return -ENOMEM;\n--\nDocumentation/translations/it_IT/locking/locktypes.rst=488=memoria. Su un kernel non-PREEMPT_RT il seguente codice funziona perfettamente::\n--\nDocumentation/translations/it_IT/locking/locktypes.rst-490-  raw_spin_lock(\u0026lock);\nDocumentation/translations/it_IT/locking/locktypes.rst:491:  p = kmalloc_obj(*p, GFP_ATOMIC);\nDocumentation/translations/it_IT/locking/locktypes.rst-492-\n--\nDocumentation/translations/it_IT/locking/locktypes.rst=497=PREEMPT_RT::\n--\nDocumentation/translations/it_IT/locking/locktypes.rst-499-  spin_lock(\u0026lock);\nDocumentation/translations/it_IT/locking/locktypes.rst:500:  p = kmalloc_obj(*p, GFP_ATOMIC);\nDocumentation/translations/it_IT/locking/locktypes.rst-501-\n--\nDocumentation/translations/it_IT/process/coding-style.rst=942=Il modo preferito per passare la dimensione di una struttura è il seguente:\n--\nDocumentation/translations/it_IT/process/coding-style.rst-945-\nDocumentation/translations/it_IT/process/coding-style.rst:946:\tp = kmalloc_obj(*p, ...);\nDocumentation/translations/it_IT/process/coding-style.rst-947-\n--\nDocumentation/translations/sp_SP/process/coding-style.rst=954=La forma preferida para pasar el tamaño de una estructura es la siguiente:\n--\nDocumentation/translations/sp_SP/process/coding-style.rst-957-\nDocumentation/translations/sp_SP/process/coding-style.rst:958:\tp = kmalloc_obj(*p, ...);\nDocumentation/translations/sp_SP/process/coding-style.rst-959-\n--\nDocumentation/translations/zh_CN/core-api/kref.rst=46=kref可以出现在数据结构体中的任何地方。\n--\nDocumentation/translations/zh_CN/core-api/kref.rst-54-\nDocumentation/translations/zh_CN/core-api/kref.rst:55:     data = kmalloc_obj(*data);\nDocumentation/translations/zh_CN/core-api/kref.rst-56-     if (!data)\n--\nDocumentation/translations/zh_CN/core-api/kref.rst=62=Kref规则\n--\nDocumentation/translations/zh_CN/core-api/kref.rst-108-\tstruct task_struct *task;\nDocumentation/translations/zh_CN/core-api/kref.rst:109:\tdata = kmalloc_obj(*data);\nDocumentation/translations/zh_CN/core-api/kref.rst-110-\tif (!data)\n--\nDocumentation/translations/zh_CN/process/coding-style.rst=810=Documentation/translations/zh_CN/core-api/memory-allocation.rst 。\n--\nDocumentation/translations/zh_CN/process/coding-style.rst-815-\nDocumentation/translations/zh_CN/process/coding-style.rst:816:\tp = kmalloc_obj(*p, ...);\nDocumentation/translations/zh_CN/process/coding-style.rst-817-\n--\nDocumentation/translations/zh_TW/process/coding-style.rst=824=Documentation/translations/zh_CN/core-api/memory-allocation.rst 。\n--\nDocumentation/translations/zh_TW/process/coding-style.rst-829-\nDocumentation/translations/zh_TW/process/coding-style.rst:830:\tp = kmalloc_obj(*p, ...);\nDocumentation/translations/zh_TW/process/coding-style.rst-831-\n--\narch/alpha/kernel/core_marvel.c=857=marvel_agp_setup(alpha_agp_info *agp)\n--\narch/alpha/kernel/core_marvel.c-863-\narch/alpha/kernel/core_marvel.c:864:\taper = kmalloc_obj(*aper);\narch/alpha/kernel/core_marvel.c-865-\tif (aper == NULL) return -ENOMEM;\n--\narch/alpha/kernel/core_marvel.c=1019=marvel_agp_info(void)\n--\narch/alpha/kernel/core_marvel.c-1061-\t */\narch/alpha/kernel/core_marvel.c:1062:\tagp = kmalloc_obj(*agp);\narch/alpha/kernel/core_marvel.c-1063-\tif (!agp)\n--\narch/alpha/kernel/core_titan.c=590=titan_agp_setup(alpha_agp_info *agp)\n--\narch/alpha/kernel/core_titan.c-596-\narch/alpha/kernel/core_titan.c:597:\taper = kmalloc_obj(struct titan_agp_aperture);\narch/alpha/kernel/core_titan.c-598-\tif (aper == NULL)\n--\narch/alpha/kernel/core_titan.c=731=titan_agp_info(void)\n--\narch/alpha/kernel/core_titan.c-762-\t */\narch/alpha/kernel/core_titan.c:763:\tagp = kmalloc_obj(*agp);\narch/alpha/kernel/core_titan.c-764-\tif (!agp)\n--\narch/alpha/kernel/module.c=29=process_reloc_for_got(Elf64_Rela *rela,\n--\narch/alpha/kernel/module.c-48-\narch/alpha/kernel/module.c:49:\tg = kmalloc_obj(*g);\narch/alpha/kernel/module.c-50-\tg-\u003enext = chains[r_sym].next;\n--\narch/alpha/kernel/pci.c=211=static void pdev_save_srm_config(struct pci_dev *dev)\n--\narch/alpha/kernel/pci.c-223-\narch/alpha/kernel/pci.c:224:\ttmp = kmalloc_obj(*tmp);\narch/alpha/kernel/pci.c-225-\tif (!tmp) {\n--\narch/arc/kernel/unwind.c=359=void *unwind_add_table(struct module *module, const void *table_start,\n--\narch/arc/kernel/unwind.c-368-\narch/arc/kernel/unwind.c:369:\ttable = kmalloc_obj(*table);\narch/arc/kernel/unwind.c-370-\tif (!table)\n--\narch/arm/common/locomo.c=274=static int locomo_suspend(struct platform_device *dev, pm_message_t state)\n--\narch/arm/common/locomo.c-279-\narch/arm/common/locomo.c:280:\tsave = kmalloc_obj(struct locomo_save_data);\narch/arm/common/locomo.c-281-\tif (!save)\n--\narch/arm/common/sa1111.c=964=static int sa1111_suspend_noirq(struct device *dev)\n--\narch/arm/common/sa1111.c-971-\narch/arm/common/sa1111.c:972:\tsave = kmalloc_obj(struct sa1111_save_data);\narch/arm/common/sa1111.c-973-\tif (!save)\n--\narch/arm/kernel/unwind.c=572=struct unwind_table *unwind_table_add(unsigned long start, unsigned long size,\n--\narch/arm/kernel/unwind.c-576-\tunsigned long flags;\narch/arm/kernel/unwind.c:577:\tstruct unwind_table *tab = kmalloc_obj(*tab);\narch/arm/kernel/unwind.c-578-\n--\narch/arm/mach-omap2/omap-iommu.c=53=static struct powerdomain *_get_pwrdm(struct device *dev)\n--\narch/arm/mach-omap2/omap-iommu.c-101-\narch/arm/mach-omap2/omap-iommu.c:102:\tentry = kmalloc_obj(*entry);\narch/arm/mach-omap2/omap-iommu.c-103-\tif (entry) {\n--\narch/arm/mach-omap2/pm34xx.c=406=static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)\n--\narch/arm/mach-omap2/pm34xx.c-412-\narch/arm/mach-omap2/pm34xx.c:413:\tpwrst = kmalloc_obj(struct power_state, GFP_ATOMIC);\narch/arm/mach-omap2/pm34xx.c-414-\tif (!pwrst)\n--\narch/arm/mach-omap2/pm44xx.c=113=static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)\n--\narch/arm/mach-omap2/pm44xx.c-134-\narch/arm/mach-omap2/pm44xx.c:135:\tpwrst = kmalloc_obj(struct power_state, GFP_ATOMIC);\narch/arm/mach-omap2/pm44xx.c-136-\tif (!pwrst)\n--\narch/arm/mm/pgd.c-19-#ifdef CONFIG_ARM_LPAE\narch/arm/mm/pgd.c:20:#define _pgd_alloc(mm)\t\tkmalloc_objs(pgd_t, PTRS_PER_PGD, GFP_KERNEL | __GFP_ZERO)\narch/arm/mm/pgd.c-21-#define _pgd_free(mm, pgd)\tkfree(pgd)\n--\narch/arm/probes/kprobes/test-core.c=764=static int coverage_start(const union decode_item *table)\narch/arm/probes/kprobes/test-core.c-765-{\narch/arm/probes/kprobes/test-core.c:766:\tcoverage.base = kmalloc_objs(struct coverage_entry,\narch/arm/probes/kprobes/test-core.c-767-\t\t\t\t     MAX_COVERAGE_ENTRIES);\n--\narch/arm64/kvm/pmu-emul.c=774=void kvm_host_pmu_init(struct arm_pmu *pmu)\n--\narch/arm64/kvm/pmu-emul.c-786-\narch/arm64/kvm/pmu-emul.c:787:\tentry = kmalloc_obj(*entry);\narch/arm64/kvm/pmu-emul.c-788-\tif (!entry)\n--\narch/arm64/kvm/vgic/vgic-debug.c=102=static void *vgic_debug_start(struct seq_file *s, loff_t *pos)\n--\narch/arm64/kvm/vgic/vgic-debug.c-106-\narch/arm64/kvm/vgic/vgic-debug.c:107:\titer = kmalloc_obj(*iter);\narch/arm64/kvm/vgic/vgic-debug.c-108-\tif (!iter)\n--\narch/arm64/kvm/vgic/vgic-debug.c=364=static void *vgic_its_debug_start(struct seq_file *s, loff_t *pos)\n--\narch/arm64/kvm/vgic/vgic-debug.c-377-\narch/arm64/kvm/vgic/vgic-debug.c:378:\titer = kmalloc_obj(*iter);\narch/arm64/kvm/vgic/vgic-debug.c-379-\tif (!iter)\n--\narch/arm64/kvm/vgic/vgic-init.c=743=void __init vgic_set_kvm_info(const struct gic_kvm_info *info)\n--\narch/arm64/kvm/vgic/vgic-init.c-745-\tBUG_ON(gic_kvm_info != NULL);\narch/arm64/kvm/vgic/vgic-init.c:746:\tgic_kvm_info = kmalloc_obj(*gic_kvm_info);\narch/arm64/kvm/vgic/vgic-init.c-747-\tif (gic_kvm_info)\n--\narch/m68k/emu/nfblock.c=97=static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)\n--\narch/m68k/emu/nfblock.c-114-\narch/m68k/emu/nfblock.c:115:\tdev = kmalloc_obj(struct nfhd_device);\narch/m68k/emu/nfblock.c-116-\tif (!dev)\n--\narch/m68k/mm/kmap.c=108=static struct vm_struct *get_io_area(unsigned long size)\n--\narch/m68k/mm/kmap.c-112-\narch/m68k/mm/kmap.c:113:\tarea = kmalloc_obj(*area);\narch/m68k/mm/kmap.c-114-\tif (!area)\n--\narch/mips/alchemy/common/dbdma.c=253=u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid,\n--\narch/mips/alchemy/common/dbdma.c-312-\t\t\t */\narch/mips/alchemy/common/dbdma.c:313:\t\t\tctp = kmalloc_obj(chan_tab_t, GFP_ATOMIC);\narch/mips/alchemy/common/dbdma.c-314-\t\t\tchan_tab_ptr[i] = ctp;\n--\narch/mips/alchemy/common/dbdma.c=391=u32 au1xxx_dbdma_ring_alloc(u32 chanid, int entries)\n--\narch/mips/alchemy/common/dbdma.c-414-\t */\narch/mips/alchemy/common/dbdma.c:415:\tdesc_base = (u32) kmalloc_objs(au1x_ddma_desc_t, entries,\narch/mips/alchemy/common/dbdma.c-416-\t\t\t\t       GFP_KERNEL | GFP_DMA);\n--\narch/mips/kernel/module.c=59=static int apply_r_mips_hi16(struct module *me, u32 *location, Elf_Addr v,\n--\narch/mips/kernel/module.c-74-\t */\narch/mips/kernel/module.c:75:\tn = kmalloc_obj(*n);\narch/mips/kernel/module.c-76-\tif (!n)\n--\narch/mips/kernel/vpe.c=311=static int apply_r_mips_hi16(struct module *me, uint32_t *location,\n--\narch/mips/kernel/vpe.c-320-\t */\narch/mips/kernel/vpe.c:321:\tn = kmalloc_obj(*n);\narch/mips/kernel/vpe.c-322-\tif (!n)\n--\narch/parisc/kernel/inventory.c=188=pat_query_module(ulong pcell_loc, ulong mod_index)\n--\narch/parisc/kernel/inventory.c-195-\narch/parisc/kernel/inventory.c:196:\tpa_pdc_cell = kmalloc_obj(*pa_pdc_cell);\narch/parisc/kernel/inventory.c-197-\tif (!pa_pdc_cell)\n--\narch/parisc/kernel/inventory.c=532=add_system_map_addresses(struct parisc_device *dev, int num_addrs, \n--\narch/parisc/kernel/inventory.c-538-\narch/parisc/kernel/inventory.c:539:\tdev-\u003eaddr = kmalloc_objs(*dev-\u003eaddr, num_addrs);\narch/parisc/kernel/inventory.c-540-\tif(!dev-\u003eaddr) {\n--\narch/parisc/kernel/processor.c=81=static int __init processor_probe(struct parisc_device *dev)\n--\narch/parisc/kernel/processor.c-112-\narch/parisc/kernel/processor.c:113:\t\tpa_pdc_cell = kmalloc_obj(*pa_pdc_cell);\narch/parisc/kernel/processor.c-114-\t\tif (!pa_pdc_cell)\n--\narch/parisc/kernel/unwind.c=149=unwind_table_add(const char *name, unsigned long base_addr, \n--\narch/parisc/kernel/unwind.c-159-\narch/parisc/kernel/unwind.c:160:\ttable = kmalloc_obj(struct unwind_table, GFP_USER);\narch/parisc/kernel/unwind.c-161-\tif (table == NULL)\n--\narch/parisc/kernel/unwind.c=406=void unwind_frame_init_from_blocked_task(struct unwind_frame_info *info, struct task_struct *t)\n--\narch/parisc/kernel/unwind.c-410-\narch/parisc/kernel/unwind.c:411:\tr2 = kmalloc_obj(struct pt_regs, GFP_ATOMIC);\narch/parisc/kernel/unwind.c-412-\tif (!r2)\n--\narch/powerpc/kernel/nvram_64.c=984=int __init nvram_scan_partitions(void)\n--\narch/powerpc/kernel/nvram_64.c-1032-\t\t}\narch/powerpc/kernel/nvram_64.c:1033:\t\ttmp_part = kmalloc_obj(*tmp_part);\narch/powerpc/kernel/nvram_64.c-1034-\t\terr = -ENOMEM;\n--\narch/powerpc/kvm/e500_mmu.c=731=int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,\n--\narch/powerpc/kvm/e500_mmu.c-774-\t\t    cfg-\u003earray / PAGE_SIZE;\narch/powerpc/kvm/e500_mmu.c:775:\tpages = kmalloc_objs(*pages, num_pages);\narch/powerpc/kvm/e500_mmu.c-776-\tif (!pages)\n--\narch/powerpc/kvm/e500_mmu.c=898=int kvmppc_e500_tlb_init(struct kvmppc_vcpu_e500 *vcpu_e500)\n--\narch/powerpc/kvm/e500_mmu.c-914-\narch/powerpc/kvm/e500_mmu.c:915:\tvcpu_e500-\u003egtlb_arch = kmalloc_objs(*vcpu_e500-\u003egtlb_arch,\narch/powerpc/kvm/e500_mmu.c-916-\t\t\t\t\t    KVM_E500_TLB0_SIZE + KVM_E500_TLB1_SIZE);\n--\narch/powerpc/lib/rheap.c=45=static int grow(rh_info_t * info, int max_blocks)\n--\narch/powerpc/lib/rheap.c-56-\narch/powerpc/lib/rheap.c:57:\tblock = kmalloc_objs(rh_block_t, max_blocks, GFP_ATOMIC);\narch/powerpc/lib/rheap.c-58-\tif (block == NULL)\n--\narch/powerpc/lib/rheap.c=253=rh_info_t *rh_create(unsigned int alignment)\n--\narch/powerpc/lib/rheap.c-260-\narch/powerpc/lib/rheap.c:261:\tinfo = kmalloc_obj(*info, GFP_ATOMIC);\narch/powerpc/lib/rheap.c-262-\tif (info == NULL)\n--\narch/powerpc/mm/book3s64/mmu_context.c=95=static int hash__init_new_context(struct mm_struct *mm)\n--\narch/powerpc/mm/book3s64/mmu_context.c-98-\narch/powerpc/mm/book3s64/mmu_context.c:99:\tmm-\u003econtext.hash_context = kmalloc_obj(struct hash_mm_context);\narch/powerpc/mm/book3s64/mmu_context.c-100-\tif (!mm-\u003econtext.hash_context)\n--\narch/powerpc/mm/book3s64/mmu_context.c-125-\t\tif (current-\u003emm-\u003econtext.hash_context-\u003espt) {\narch/powerpc/mm/book3s64/mmu_context.c:126:\t\t\tmm-\u003econtext.hash_context-\u003espt = kmalloc_obj(struct subpage_prot_table);\narch/powerpc/mm/book3s64/mmu_context.c-127-\t\t\tif (!mm-\u003econtext.hash_context-\u003espt) {\n--\narch/powerpc/perf/hv-24x7.c=623=static int event_uniq_add(struct rb_root *root, const char *name, int nl,\n--\narch/powerpc/perf/hv-24x7.c-650-\narch/powerpc/perf/hv-24x7.c:651:\tdata = kmalloc_obj(*data);\narch/powerpc/perf/hv-24x7.c-652-\tif (!data)\n--\narch/powerpc/perf/hv-24x7.c=755=static int create_events_from_catalog(struct attribute ***events_,\n--\narch/powerpc/perf/hv-24x7.c-908-\narch/powerpc/perf/hv-24x7.c:909:\tevents = kmalloc_objs(*events, attr_max + 1);\narch/powerpc/perf/hv-24x7.c-910-\tif (!events) {\n--\narch/powerpc/perf/hv-24x7.c-914-\narch/powerpc/perf/hv-24x7.c:915:\tevent_descs = kmalloc_objs(*event_descs, event_idx + 1);\narch/powerpc/perf/hv-24x7.c-916-\tif (!event_descs) {\n--\narch/powerpc/perf/hv-24x7.c-920-\narch/powerpc/perf/hv-24x7.c:921:\tevent_long_descs = kmalloc_objs(*event_long_descs, event_idx + 1);\narch/powerpc/perf/hv-24x7.c-922-\tif (!event_long_descs) {\n--\narch/powerpc/platforms/44x/hsta_msi.c=122=static int hsta_msi_probe(struct platform_device *pdev)\n--\narch/powerpc/platforms/44x/hsta_msi.c-153-\narch/powerpc/platforms/44x/hsta_msi.c:154:\tppc4xx_hsta_msi.irq_map = kmalloc_objs(int, irq_count);\narch/powerpc/platforms/44x/hsta_msi.c-155-\tif (!ppc4xx_hsta_msi.irq_map) {\n--\narch/powerpc/platforms/cell/spufs/file.c=44=static int spufs_attr_open(struct inode *inode, struct file *file,\n--\narch/powerpc/platforms/cell/spufs/file.c-49-\narch/powerpc/platforms/cell/spufs/file.c:50:\tattr = kmalloc_obj(*attr);\narch/powerpc/platforms/cell/spufs/file.c-51-\tif (!attr)\n--\narch/powerpc/platforms/pseries/dlpar.c=628=void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog)\n--\narch/powerpc/platforms/pseries/dlpar.c-636-\narch/powerpc/platforms/pseries/dlpar.c:637:\twork = kmalloc_obj(struct pseries_hp_work, GFP_ATOMIC);\narch/powerpc/platforms/pseries/dlpar.c-638-\tif (work) {\n--\narch/powerpc/platforms/pseries/hvcserver.c=119=int hvcs_get_partner_info(uint32_t unit_address, struct list_head *head,\n--\narch/powerpc/platforms/pseries/hvcserver.c-162-\t\t * hvcs_free_partner_info(). */\narch/powerpc/platforms/pseries/hvcserver.c:163:\t\tnext_partner_info = kmalloc_obj(struct hvcs_partner_info,\narch/powerpc/platforms/pseries/hvcserver.c-164-\t\t\t\t\t\tGFP_ATOMIC);\n--\narch/powerpc/platforms/pseries/lparcfg.c=144=static void show_gpci_data(struct seq_file *m)\n--\narch/powerpc/platforms/pseries/lparcfg.c-149-\narch/powerpc/platforms/pseries/lparcfg.c:150:\tbuf = kmalloc_obj(*buf);\narch/powerpc/platforms/pseries/lparcfg.c-151-\tif (buf == NULL)\n--\narch/powerpc/platforms/pseries/msi.c=435=static int pseries_msi_ops_prepare(struct irq_domain *domain, struct device *dev,\n--\narch/powerpc/platforms/pseries/msi.c-443-\tstruct pseries_msi_device *pseries_dev __free(kfree)\narch/powerpc/platforms/pseries/msi.c:444:\t\t= kmalloc_obj(*pseries_dev);\narch/powerpc/platforms/pseries/msi.c-445-\tif (!pseries_dev)\n--\narch/powerpc/platforms/pseries/pci.c=120=static int pseries_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)\n--\narch/powerpc/platforms/pseries/pci.c-143-\tpdn = pci_get_pdn(pdev);\narch/powerpc/platforms/pseries/pci.c:144:\tpdn-\u003epe_num_map = kmalloc_objs(*pdn-\u003epe_num_map, num_vfs);\narch/powerpc/platforms/pseries/pci.c-145-\tif (!pdn-\u003epe_num_map)\n--\narch/powerpc/platforms/pseries/vas.c=1076=static int __init pseries_vas_init(void)\n--\narch/powerpc/platforms/pseries/vas.c-1089-\narch/powerpc/platforms/pseries/vas.c:1090:\thv_caps = kmalloc_obj(*hv_caps);\narch/powerpc/platforms/pseries/vas.c-1091-\tif (!hv_caps)\n--\narch/powerpc/platforms/pseries/vio.c=705=static int vio_cmo_bus_probe(struct vio_dev *viodev)\n--\narch/powerpc/platforms/pseries/vio.c-747-\narch/powerpc/platforms/pseries/vio.c:748:\t\tdev_ent = kmalloc_obj(struct vio_cmo_dev_entry);\narch/powerpc/platforms/pseries/vio.c-749-\t\tif (!dev_ent)\n--\narch/powerpc/sysdev/fsl_lbc.c=352=static int fsl_lbc_syscore_suspend(void *data)\n--\narch/powerpc/sysdev/fsl_lbc.c-364-\narch/powerpc/sysdev/fsl_lbc.c:365:\tctrl-\u003esaved_regs = kmalloc_obj(struct fsl_lbc_regs);\narch/powerpc/sysdev/fsl_lbc.c-366-\tif (!ctrl-\u003esaved_regs)\n--\narch/powerpc/sysdev/mpic.c=1549=void __init mpic_init(struct mpic *mpic)\n--\narch/powerpc/sysdev/mpic.c-1641-\t/* allocate memory to save mpic state */\narch/powerpc/sysdev/mpic.c:1642:\tmpic-\u003esave_data = kmalloc_objs(*mpic-\u003esave_data, mpic-\u003enum_sources);\narch/powerpc/sysdev/mpic.c-1643-\tBUG_ON(mpic-\u003esave_data == NULL);\n--\narch/powerpc/sysdev/of_rtc.c=23=void __init of_instantiate_rtc(void)\n--\narch/powerpc/sysdev/of_rtc.c-35-\narch/powerpc/sysdev/of_rtc.c:36:\t\t\tres = kmalloc_obj(*res);\narch/powerpc/sysdev/of_rtc.c-37-\t\t\tif (!res) {\n--\narch/riscv/kernel/module.c=654=static int add_relocation_to_accumulate(struct module *me, int type,\n--\narch/riscv/kernel/module.c-665-\narch/riscv/kernel/module.c:666:\tentry = kmalloc_obj(*entry);\narch/riscv/kernel/module.c-667-\n--\narch/riscv/kernel/module.c-699-\tif (!found) {\narch/riscv/kernel/module.c:700:\t\trel_head = kmalloc_obj(*rel_head);\narch/riscv/kernel/module.c-701-\n--\narch/riscv/kernel/module.c-711-\t\t\tbucket =\narch/riscv/kernel/module.c:712:\t\t\t\tkmalloc_obj(struct used_bucket);\n\n"
}

gemini-3.1-pro-preview

null

null

							input: 26009
							output: 256
							thoughts: 1949
						

**Analysis of the TLS Record Fragmentation Bug**

Okay, let's break this down. It seems we're dealing with a potential out-of-bounds write in the TLS offload code. `kmalloc_obj`... right, it allocates memory for a `tls_record_info` struct. Crucially, it doesn't zero it, unlike `kzalloc`. The code in `tls_create_new_record` allocates the struct, initializes the first fragment, and sets `num_frags` to 1. The key point here is that the rest of the `frags` array within `tls_record_info` *isn't* initialized initially.

`tls_append_frag` is responsible for adding subsequent fragments. It updates the fragment descriptor before incrementing `num_frags`, which is good. Important: `end_seq` and `list` are initialized later in `tls_push_record`.

The potential vulnerability is pretty clear. If `num_frags` somehow exceeds `MAX_SKB_FRAGS`, the code will write beyond the bounds of the `frags` array. Specifically, the write is to `&record->frags[record->num_frags]`, which will be `record->frags[MAX_SKB_FRAGS]` if `num_frags` has the maximum possible value. There's also a potential out-of-bounds read in the `tls_append_frag` function, when checking if a new fragment should be appended to the current one. It reads memory past the end of the `frags` array.

Now, does this lead to uninitialized memory being *used* or leaked? The record itself is internal to the kernel, so there's no direct exposure to userspace. The fragments point to pages holding the data, and that data is *copied* from userspace. So no uninitialized data leaking.

The bug is an out-of-bounds read/write on the `frags` array. The fix addresses this problem.

KASAN will detect the out-of-bounds access. KMSAN is for uninitialized reads. In this case, KASAN will catch the fundamental problem: writing to `record->frags[MAX_SKB_FRAGS]`. Even if the accessed memory has uninitialized data or data from a neighboring slab object, it's irrelevant, because the KASAN will detect the access. KMSAN is not needed because the underlying problem is not about reading uninitialized variables.

Let's do a quick review. Is `num_frags` uninitialized? No. `len`? No. The individual fragment elements of `frags`? No, because `frags[0]` is initialized and the rest is initialized before incrementing `num_frags`.

So the only issue is the out-of-bounds access, which KASAN is built to handle. Thus, `NeedsKMSAN = false`.

Now, the rules!

We should set `NeedsKMSAN = true` if the patch involves:
1.  Kernel structures sent to user space with uninitialized fields.
2.  Conditional logic based on uninitialized variables.
3.  Allocation of complex data structures with uninitialized fields.
4.  Bounds checks and potential access of uninitialized bytes.

We set `NeedsKMSAN = false` if the primary risk is out-of-bounds access, array overflows, NULL pointer dereferences, locking deadlocks, or use-after-free bugs.

This patch fixes an array overflow/out-of-bounds access on `record->frags`. So, `NeedsKMSAN = false`.

The reasoning is as follows. The patch modifies the condition in `tls_push_data` to prevent a TLS record being left open if its fragment count (`num_frags`) has reached `MAX_SKB_FRAGS - 1`. The original code could leave the record open if `size == 0` and `MSG_MORE` was set, even if `num_frags` was already at its maximum. Subsequently, on the next call to `tls_push_data`, `tls_append_frag` could be called, which would increment `num_frags` past `MAX_SKB_FRAGS`, causing an out-of-bounds read and write on the `record->frags` array. This is an array overflow vulnerability, which KASAN detects. There's no uninitialized memory being directly exposed to userspace; no information is leaked. A KMSAN fuzzing session is not necessary.

{
  "KMSANReasoning": "The patch modifies the condition in `tls_push_data` to prevent leaving a TLS record open if its fragment count (`num_frags`) has reached `MAX_SKB_FRAGS - 1`. Prior to this patch, if `size == 0` and `MSG_MORE` was set, the code would break out of the loop and leave the record open, even if `num_frags` was already at the maximum allowed value. On the next call to `tls_push_data`, `tls_append_frag` could be called on this open record, which would increment `num_frags` beyond `MAX_SKB_FRAGS` and cause an out-of-bounds read and write on the `record-\u003efrags` array.\n\nThis is a classic array overflow / out-of-bounds access bug. KASAN is specifically designed to detect out-of-bounds accesses and will reliably catch this bug. There is no uninitialized memory usage or information leak to user space involved here. Therefore, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false
}

{
  "KMSANReasoning": "The patch modifies the condition in `tls_push_data` to prevent leaving a TLS record open if its fragment count (`num_frags`) has reached `MAX_SKB_FRAGS - 1`. Prior to this patch, if `size == 0` and `MSG_MORE` was set, the code would break out of the loop and leave the record open, even if `num_frags` was already at the maximum allowed value. On the next call to `tls_push_data`, `tls_append_frag` could be called on this open record, which would increment `num_frags` beyond `MAX_SKB_FRAGS` and cause an out-of-bounds read and write on the `record-\u003efrags` array.\n\nThis is a classic array overflow / out-of-bounds access bug. KASAN is specifically designed to detect out-of-bounds accesses and will reliably catch this bug. There is no uninitialized memory usage or information leak to user space involved here. Therefore, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false
}