AI Trajectory

null

{
  "EnableConfigs": [
    "INET_PSP"
  ],
  "FocusSymbols": [
    "psp_nl_multicast_per_ns",
    "psp_nl_dev_set_doit",
    "psp_nl_key_rotate_doit",
    "psp_nl_dev_assoc_doit",
    "psp_nl_dev_disassoc_doit"
  ],
  "Reasoning": "The patch fixes netns lifetime management in `psp_nl_multicast_per_ns` by adding `maybe_get_net` and `put_net`. This is functional and reachable via PSP netlink commands.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 02f0e4722f595e27a866e7dfd1c919296c73af03\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Fri Jul 3 12:21:49 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/psp/psp_nl.c b/net/psp/psp_nl.c\nindex 9610d8c456ff55..24ab626a9e8a10 100644\n--- a/net/psp/psp_nl.c\n+++ b/net/psp/psp_nl.c\n@@ -62,36 +62,45 @@ psp_nl_multicast_per_ns(struct psp_dev *psd, unsigned int group,\n \tstruct net *main_net;\n \tstruct sk_buff *ntf;\n \n-\tmain_net = dev_net(psd-\u003emain_netdev);\n+\tmain_net = maybe_get_net(dev_net(psd-\u003emain_netdev));\n+\tif (!main_net)\n+\t\treturn;\n+\n \txa_init(\u0026sent_nets);\n \n \tlist_for_each_entry(entry, \u0026psd-\u003eassoc_dev_list, dev_list) {\n \t\tstruct net *assoc_net = dev_net(entry-\u003eassoc_dev);\n+\t\tstruct net *net;\n \t\tint ret;\n \n \t\tif (net_eq(assoc_net, main_net))\n \t\t\tcontinue;\n \n-\t\tret = xa_insert(\u0026sent_nets, (unsigned long)assoc_net, assoc_net,\n-\t\t\t\tGFP_KERNEL);\n-\t\tif (ret == -EBUSY)\n+\t\tnet = maybe_get_net(assoc_net);\n+\t\tif (!net)\n \t\t\tcontinue;\n \n-\t\tntf = build_ntf(psd, assoc_net, ctx);\n-\t\tif (!ntf)\n+\t\tret = xa_insert(\u0026sent_nets, (unsigned long)assoc_net, assoc_net,\n+\t\t\t\tGFP_KERNEL);\n+\t\tif (ret == -EBUSY) {\n+\t\t\tput_net(net);\n \t\t\tcontinue;\n+\t\t}\n \n-\t\tgenlmsg_multicast_netns(\u0026psp_nl_family, assoc_net, ntf, 0,\n-\t\t\t\t\tgroup, GFP_KERNEL);\n+\t\tntf = build_ntf(psd, net, ctx);\n+\t\tif (ntf)\n+\t\t\tgenlmsg_multicast_netns(\u0026psp_nl_family, net, ntf, 0,\n+\t\t\t\t\t\tgroup, GFP_KERNEL);\n+\t\tput_net(net);\n \t}\n \txa_destroy(\u0026sent_nets);\n \n \t/* Send to main device netns */\n \tntf = build_ntf(psd, main_net, ctx);\n-\tif (!ntf)\n-\t\treturn;\n-\tgenlmsg_multicast_netns(\u0026psp_nl_family, main_net, ntf, 0, group,\n-\t\t\t\tGFP_KERNEL);\n+\tif (ntf)\n+\t\tgenlmsg_multicast_netns(\u0026psp_nl_family, main_net, ntf, 0, group,\n+\t\t\t\t\tGFP_KERNEL);\n+\tput_net(main_net);\n }\n \n static struct sk_buff *psp_nl_clone_ntf(struct psp_dev *psd, struct net *net,\n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": [
    "INET_PSP"
  ],
  "FocusSymbols": [
    "psp_nl_multicast_per_ns",
    "psp_nl_dev_set_doit",
    "psp_nl_key_rotate_doit",
    "psp_nl_dev_assoc_doit",
    "psp_nl_dev_disassoc_doit"
  ],
  "Reasoning": "The patch fixes netns lifetime management in `psp_nl_multicast_per_ns` by adding `maybe_get_net` and `put_net`. This is functional and reachable via PSP netlink commands.",
  "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).

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.
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.
   Do not list too generic configs (we already have them enabled). Only list those that
   specifically cover the modified code. 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 02f0e4722f595e27a866e7dfd1c919296c73af03
Author: syz-cluster <triage@syzkaller.com>
Date:   Fri Jul 3 12:21:49 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/psp/psp_nl.c b/net/psp/psp_nl.c
index 9610d8c456ff55..24ab626a9e8a10 100644
--- a/net/psp/psp_nl.c
+++ b/net/psp/psp_nl.c
@@ -62,36 +62,45 @@ psp_nl_multicast_per_ns(struct psp_dev *psd, unsigned int group,
 	struct net *main_net;
 	struct sk_buff *ntf;
 
-	main_net = dev_net(psd->main_netdev);
+	main_net = maybe_get_net(dev_net(psd->main_netdev));
+	if (!main_net)
+		return;
+
 	xa_init(&sent_nets);
 
 	list_for_each_entry(entry, &psd->assoc_dev_list, dev_list) {
 		struct net *assoc_net = dev_net(entry->assoc_dev);
+		struct net *net;
 		int ret;
 
 		if (net_eq(assoc_net, main_net))
 			continue;
 
-		ret = xa_insert(&sent_nets, (unsigned long)assoc_net, assoc_net,
-				GFP_KERNEL);
-		if (ret == -EBUSY)
+		net = maybe_get_net(assoc_net);
+		if (!net)
 			continue;
 
-		ntf = build_ntf(psd, assoc_net, ctx);
-		if (!ntf)
+		ret = xa_insert(&sent_nets, (unsigned long)assoc_net, assoc_net,
+				GFP_KERNEL);
+		if (ret == -EBUSY) {
+			put_net(net);
 			continue;
+		}
 
-		genlmsg_multicast_netns(&psp_nl_family, assoc_net, ntf, 0,
-					group, GFP_KERNEL);
+		ntf = build_ntf(psd, net, ctx);
+		if (ntf)
+			genlmsg_multicast_netns(&psp_nl_family, net, ntf, 0,
+						group, GFP_KERNEL);
+		put_net(net);
 	}
 	xa_destroy(&sent_nets);
 
 	/* Send to main device netns */
 	ntf = build_ntf(psd, main_net, ctx);
-	if (!ntf)
-		return;
-	genlmsg_multicast_netns(&psp_nl_family, main_net, ntf, 0, group,
-				GFP_KERNEL);
+	if (ntf)
+		genlmsg_multicast_netns(&psp_nl_family, main_net, ntf, 0, group,
+					GFP_KERNEL);
+	put_net(main_net);
 }
 
 static struct sk_buff *psp_nl_clone_ntf(struct psp_dev *psd, struct net *net,

gemini-3.1-pro-preview

null

null

							input: 2403
							output: 34
							thoughts: 97
						

**Analyzing the Network Namespace Management in `net/psp/psp_nl.c`**

Okay, so there's a patch in `net/psp/psp_nl.c` and it's dealing with the function `psp_nl_multicast_per_ns`. The core of the change seems to be around how we're handling `struct net` pointers – specifically, the introduction of `maybe_get_net` and `put_net`.  This immediately tells me we were likely having lifetime management issues with the network namespaces. My immediate thought is to delve into `net/psp/psp_nl.c` itself. I need to understand what `psp_nl_multicast_per_ns` is *supposed* to be doing within the context of the PSP subsystem.  What kind of network configuration is this feature even tied to?  The underlying config options will be critical to understanding the scope and potential impact of this change. I need to see the dependencies. We should check the config settings which enable `psp_nl_multicast_per_ns`. The specific use case and configuration options will determine the severity. I suspect that there was a memory issue with the lifetime of the `net` struct.

{
  "Expression": "psp_nl_multicast_per_ns",
  "PathPrefix": "net/psp/"
}

{
  "Output": "net/psp/psp_nl.c=34=static int psp_nl_reply_send(struct sk_buff *rsp, struct genl_info *info)\n--\nnet/psp/psp_nl.c-42-/**\nnet/psp/psp_nl.c:43: * psp_nl_multicast_per_ns() - multicast a notification to each unique netns\nnet/psp/psp_nl.c-44- * @psd: PSP device (must be locked)\n--\nnet/psp/psp_nl.c=53=static void\nnet/psp/psp_nl.c:54:psp_nl_multicast_per_ns(struct psp_dev *psd, unsigned int group,\nnet/psp/psp_nl.c-55-\t\t\tstruct sk_buff *(*build_ntf)(struct psp_dev *,\n--\nnet/psp/psp_nl.c=112=static void psp_nl_multicast_all_ns(struct psp_dev *psd, struct sk_buff *ntf,\n--\nnet/psp/psp_nl.c-114-{\nnet/psp/psp_nl.c:115:\tpsp_nl_multicast_per_ns(psd, group, psp_nl_clone_ntf, ntf);\nnet/psp/psp_nl.c-116-\tnlmsg_consume(ntf);\n--\nnet/psp/psp_nl.c=352=void psp_nl_notify_dev(struct psp_dev *psd, u32 cmd)\nnet/psp/psp_nl.c-353-{\nnet/psp/psp_nl.c:354:\tpsp_nl_multicast_per_ns(psd, PSP_NLGRP_MGMT,\nnet/psp/psp_nl.c-355-\t\t\t\tpsp_nl_build_dev_ntf, \u0026cmd);\n"
}

gemini-3.1-pro-preview

null

null

							input: 3268
							output: 22
							thoughts: 13
						

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

**Investigating `net/psp/` Configuration**

Okay, so I need to figure out which configuration options are enabling `net/psp/`. This probably means I'm looking at a kernel configuration, but I need to be more precise. The question is, which specific config options are directly or indirectly responsible for enabling this module or feature? I might start by using a tool like `grep` or `find` to search the configuration files, likely looking in the `defconfig` or `*_defconfig` files for the relevant architecture or kernel version. My mental checklist includes keywords such as "PSP," "net," or potentially, more generic terms like "networking," "security," or specific protocols that might relate to what `net/psp/` does. I'm also considering the possibility that it's enabled by some *other* configuration that indirectly causes a dependency to be satisfied. I need to be aware of dependencies. A good understanding of the kernel's Kconfig syntax is essential here; I need to quickly differentiate between direct assignments (`=y`, `=m`) and indirect dependencies (e.g., `if` statements, `depends on`). I'll need to trace those relationships if I'm not immediately seeing a direct match. The goal is to quickly pinpoint the controlling configuration options and understand their implications for the system's behavior, particularly if this relates to a security context.

{
  "Dir": "net/psp/"
}

{
  "Files": [
    "psp-nl-gen.c",
    "psp-nl-gen.h",
    "psp.h",
    "psp_main.c",
    "psp_nl.c",
    "psp_sock.c"
  ],
  "Subdirs": null
}

gemini-3.1-pro-preview

null

null

							input: 3673
							output: 24
							thoughts: 25
						

Here's a summary of my thought process:

**Kconfig Location Dilemma**

Okay, I need to figure out where the relevant configuration options are defined for this networking component. My first instinct is to check the usual suspects for Kconfig files within the networking subsystem. I'll start by looking at `net/psp/Kconfig`. If that doesn't pan out, I'll broaden the search and try `net/Kconfig` directly. Failing both of those, there's always the possibility that the build system handles the configuration in a different way. That means I’d better also take a look at `net/Makefile` to see if there's any clever logic there that sets things up. Hopefully, the information I need is in one of these locations!

{
  "Expression": "psp",
  "PathPrefix": "net/Makefile"
}

{
  "Output": "net/Makefile=20=obj-$(CONFIG_UNIX)\t\t+= unix/\nnet/Makefile:21:obj-$(CONFIG_INET_PSP)\t\t+= psp/\nnet/Makefile-22-obj-y\t\t\t\t+= ipv6/\n"
}

gemini-3.1-pro-preview

null

null

							input: 3955
							output: 27
							thoughts: 30
						

Okay, here's my take on those thoughts, framed as my own:

**Analyzing the Configuration Dependency**

Alright, so the key configuration option we're looking at here is `CONFIG_INET_PSP`. The immediate question is, is this a standalone option, or does it depend on others? We need to establish its context within the broader configuration landscape. My immediate priority is to determine if `CONFIG_INET_PSP` is the *only* factor, or if there are other, related options we must also consider. Is it a prerequisite for some other feature? Does it have any implications that are contingent on other settings? It all hinges on if it's dependent on any other configurations, or if it can be enabled independently.

{
  "Expression": "config INET_PSP",
  "PathPrefix": "net/"
}

{
  "Output": "net/psp/Kconfig-4-#\nnet/psp/Kconfig:5:config INET_PSP\nnet/psp/Kconfig-6-\tbool \"PSP Security Protocol support\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 4220
							output: 33
							thoughts: 20
						

Okay, let's dive into this. Here's my thought process on this:

**Checking for Dependencies in `net/psp/Kconfig`**

Alright, I need to get to the bottom of this. I've got a feeling there might be some underlying dependencies I'm missing. Given the context of what I'm working on, my gut tells me the `net/psp/Kconfig` file is the place to start looking for those. Kconfig files are the cornerstone of the kernel configuration system, and they often define relationships between different features and modules. So, my next logical step is to check that file and see what other components or settings it might be tied to. I'm expecting to find conditional dependencies, maybe some default values, and possibly some hidden implications that aren't immediately obvious. It's a quick and targeted check to ensure I have a complete picture. Let's see what `net/psp/Kconfig` reveals.

{
  "File": "net/psp/Kconfig",
  "FirstLine": 1,
  "LineCount": 100
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\t#\n   3:\t# PSP configuration\n   4:\t#\n   5:\tconfig INET_PSP\n   6:\t\tbool \"PSP Security Protocol support\"\n   7:\t\tdepends on INET\n   8:\t\tselect SKB_DECRYPTED\n   9:\t\tselect SKB_EXTENSIONS\n  10:\t\tselect SOCK_VALIDATE_XMIT\n  11:\t\thelp\n  12:\t\tEnable kernel support for the PSP Security Protocol (PSP).\n  13:\t\tFor more information see:\n  14:\t\t  https://raw.githubusercontent.com/google/psp/main/doc/PSP_Arch_Spec.pdf\n  15:\t\n  16:\t\tIf unsure, say N.\n"
}

gemini-3.1-pro-preview

null

null

							input: 4679
							output: 42
							thoughts: 93
						

**Analyzing the PSP Multicast Configuration**

Okay, so I'm looking at this patch and it's keyed into `INET_PSP`, which means we're dealing with the Packet Scheduling Policy. I see the main modification is to `psp_nl_multicast_per_ns`, but of course, I need to understand the implications of that. This function is called by both `psp_nl_multicast_all_ns` and `psp_nl_notify_dev`. Since these are reachable, my next logical step is to trace back the call chain of these two functions, `psp_nl_notify_dev` and `psp_nl_multicast_all_ns`, to understand *where* they're being used within the system. That should give me a good picture of the potential impact of this change.

{
  "Expression": "psp_nl_notify_dev|psp_nl_multicast_all_ns",
  "PathPrefix": "net/psp/"
}

{
  "Output": "net/psp/psp.h=19=int psp_attach_netdev_notifier(void);\nnet/psp/psp.h-20-\nnet/psp/psp.h:21:void psp_nl_notify_dev(struct psp_dev *psd, u32 cmd);\nnet/psp/psp.h-22-\n--\nnet/psp/psp_main.c=59=psp_dev_create(struct net_device *netdev,\n--\nnet/psp/psp_main.c-106-\t */\nnet/psp/psp_main.c:107:\tpsp_nl_notify_dev(psd, PSP_CMD_DEV_ADD_NTF);\nnet/psp/psp_main.c-108-\n--\nnet/psp/psp_main.c=131=void psp_dev_unregister(struct psp_dev *psd)\n--\nnet/psp/psp_main.c-138-\nnet/psp/psp_main.c:139:\tpsp_nl_notify_dev(psd, PSP_CMD_DEV_DEL_NTF);\nnet/psp/psp_main.c-140-\n--\nnet/psp/psp_main.c=424=static int psp_netdev_event(struct notifier_block *nb, unsigned long event,\n--\nnet/psp/psp_main.c-438-\t\tif (psp_dev_is_registered(psd))\nnet/psp/psp_main.c:439:\t\t\tpsp_nl_notify_dev(psd, PSP_CMD_DEV_CHANGE_NTF);\nnet/psp/psp_main.c-440-\t\tpsp_dev_disassoc_one(psd, dev);\n--\nnet/psp/psp_nl.c=106=static struct sk_buff *psp_nl_clone_ntf(struct psp_dev *psd, struct net *net,\n--\nnet/psp/psp_nl.c-111-\nnet/psp/psp_nl.c:112:static void psp_nl_multicast_all_ns(struct psp_dev *psd, struct sk_buff *ntf,\nnet/psp/psp_nl.c-113-\t\t\t\t    unsigned int group)\n--\nnet/psp/psp_nl.c=328=static struct sk_buff *psp_nl_build_dev_ntf(struct psp_dev *psd,\n--\nnet/psp/psp_nl.c-351-\nnet/psp/psp_nl.c:352:void psp_nl_notify_dev(struct psp_dev *psd, u32 cmd)\nnet/psp/psp_nl.c-353-{\n--\nnet/psp/psp_nl.c=407=int psp_nl_dev_set_doit(struct sk_buff *skb, struct genl_info *info)\n--\nnet/psp/psp_nl.c-439-\nnet/psp/psp_nl.c:440:\tpsp_nl_notify_dev(psd, PSP_CMD_DEV_CHANGE_NTF);\nnet/psp/psp_nl.c-441-\n--\nnet/psp/psp_nl.c=449=int psp_nl_key_rotate_doit(struct sk_buff *skb, struct genl_info *info)\n--\nnet/psp/psp_nl.c-489-\nnet/psp/psp_nl.c:490:\tpsp_nl_multicast_all_ns(psd, ntf, PSP_NLGRP_USE);\nnet/psp/psp_nl.c-491-\n--\nnet/psp/psp_nl.c=501=int psp_nl_dev_assoc_doit(struct sk_buff *skb, struct genl_info *info)\n--\nnet/psp/psp_nl.c-569-\nnet/psp/psp_nl.c:570:\tpsp_nl_notify_dev(psd, PSP_CMD_DEV_CHANGE_NTF);\nnet/psp/psp_nl.c-571-\n--\nnet/psp/psp_nl.c=586=int psp_nl_dev_disassoc_doit(struct sk_buff *skb, struct genl_info *info)\n--\nnet/psp/psp_nl.c-625-\t */\nnet/psp/psp_nl.c:626:\tpsp_nl_notify_dev(psd, PSP_CMD_DEV_CHANGE_NTF);\nnet/psp/psp_nl.c-627-\n"
}

gemini-3.1-pro-preview

null

null

							input: 6142
							output: 147
							thoughts: 243
						

**Analyzing the Patch's Impact on Netlink and Namespaces**

Okay, so I'm looking at this patch and immediately, the key is `psp_nl_multicast_per_ns`. That's where the modification sits. And it's reachable through a handful of netlink commands – these are clearly the focus points I need to investigate. Let's make sure I've got a good list for reference:

*   `psp_nl_dev_set_doit`
*   `psp_nl_key_rotate_doit`
*   `psp_nl_dev_assoc_doit`
*   `psp_nl_dev_disassoc_doit`
*   `psp_nl_multicast_per_ns`

The relevant configuration appears to be `INET_PSP`, which simplifies the scope a little bit. I'll quickly double-check that this is the only relevant config, just to be thorough. Okay, good. It looks like `INET_PSP` is sufficient.

My reasoning is that the patch addresses some netns lifetime management issues, specifically around how `psp_nl_multicast_per_ns` behaves. The fix involves adding `maybe_get_net` and `put_net` calls, which is a good standard approach. This functionality is directly accessible through these PSP netlink commands. Now I should move on to looking at the results that should have been set, based on this change.

{
  "EnableConfigs": [
    "INET_PSP"
  ],
  "FocusSymbols": [
    "psp_nl_multicast_per_ns",
    "psp_nl_dev_set_doit",
    "psp_nl_key_rotate_doit",
    "psp_nl_dev_assoc_doit",
    "psp_nl_dev_disassoc_doit"
  ],
  "Reasoning": "The patch fixes netns lifetime management in `psp_nl_multicast_per_ns` by adding `maybe_get_net` and `put_net`. This is functional and reachable via PSP netlink commands.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "INET_PSP"
  ],
  "FocusSymbols": [
    "psp_nl_multicast_per_ns",
    "psp_nl_dev_set_doit",
    "psp_nl_key_rotate_doit",
    "psp_nl_dev_assoc_doit",
    "psp_nl_dev_disassoc_doit"
  ],
  "Reasoning": "The patch fixes netns lifetime management in `psp_nl_multicast_per_ns` by adding `maybe_get_net` and `put_net`. This is functional and reachable via PSP netlink commands.",
  "WorthFuzzing": true
}