From: syzbot <syzbot+521f7e7e2b974abde99a@syzkaller.appspotmail.com>
To: coreteam@netfilter.org, davem@davemloft.net, edumazet@google.com,
edumazet@kernel.org, fw@strlen.de, horms@kernel.org,
kuba@kernel.org, linux-kernel@vger.kernel.org,
mike.michalo@gmail.com, netdev@vger.kernel.org,
netfilter-devel@vger.kernel.org, pabeni@redhat.com,
pablo@netfilter.org, phil@nwl.cc, stable@vger.kernel.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [netfilter?] WARNING in nf_flow_table_extend_ct_timeout
Date: Thu, 22 Oct 2026 09:44:50 -0700 [thread overview]
Message-ID: <6ada3d82.d1c214cc.659fa.00db.GAE@google.com> (raw)
In-Reply-To: <6aa9c7f8.a211d2ce.1a5198.02b5.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: abeacca61eea Merge branch 'net-mlx5-hws-fix-modify-header-..
git tree: net
console+strace: https://syzkaller.appspot.com/x/log.txt?x=111f4d0d580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c4b098695335c89f
dashboard link: https://syzkaller.appspot.com/bug?extid=521f7e7e2b974abde99a
compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1491e029580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=157d410d580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/22930d0e9391/disk-abeacca6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d2e18d51f288/vmlinux-abeacca6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/69879bb16225/bzImage-abeacca6.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+521f7e7e2b974abde99a@syzkaller.appspotmail.com
------------[ cut here ]------------
1
WARNING: net/netfilter/nf_flow_table_core.c:553 at nf_flow_table_extend_ct_timeout+0x1ee/0x2f0 net/netfilter/nf_flow_table_core.c:553, CPU#1: kworker/1:2/123
Modules linked in:
CPU: 1 UID: 0 PID: 123 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: events_power_efficient nf_flow_offload_work_gc
RIP: 0010:nf_flow_table_extend_ct_timeout+0x1ee/0x2f0 net/netfilter/nf_flow_table_core.c:553
Code: 00 00 00 41 83 ff 06 0f 84 9a 00 00 00 41 83 ff 05 0f 85 b0 00 00 00 e8 e0 10 a9 f7 41 bf 30 75 00 00 eb 0f e8 d3 10 a9 f7 90 <0f> 0b 90 41 bf 01 00 00 00 48 c7 c0 80 f2 a0 8f 48 c1 e8 03 42 80
RSP: 0018:ffffc90002dcf930 EFLAGS: 00010293
RAX: ffffffff8a1effad RBX: ffff888027a52900 RCX: ffff88801ffa1f40
RDX: 0000000000000000 RSI: ffffffff912fa640 RDI: 000000000000002f
RBP: 0000000000000737 R08: ffff88801ffa1f40 R09: 0000000000000002
R10: 0000000000000011 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff11004f4a538 R14: ffff888027a52948 R15: 000000000000002f
FS: 0000000000000000(0000) GS:ffff888123bbd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f926bd5bd3c CR3: 000000000fb48000 CR4: 00000000003526f0
Call Trace:
<TASK>
nf_flow_offload_gc_step+0x5aa/0x840 net/netfilter/nf_flow_table_core.c:593
nf_flow_table_iterate+0x13c/0x1f0 net/netfilter/nf_flow_table_core.c:459
nf_flow_table_gc_run net/netfilter/nf_flow_table_core.c:616 [inline]
nf_flow_offload_work_gc+0x22/0x70 net/netfilter/nf_flow_table_core.c:624
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
next prev parent reply other threads:[~2026-10-22 16:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-15 22:34 syzbot
2026-10-22 16:44 ` syzbot [this message]
2026-10-22 17:02 ` mixalhs
2026-10-22 17:20 ` syzbot
2026-10-22 17:24 ` Forwarded: " syzbot
2026-10-22 17:29 ` syzbot
[not found] <CAO+rqLihzHZx5kUUdR7mcC=yApCUP_20OEh7KZOQhHY5_+KLYQ@mail.gmail.com>
2026-10-22 17:26 ` syzbot
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