Re: [syzbot] [net?] WARNING: locking bug in tcp_tsq_handler

From: syzbot

Date: Wed Aug 26 2026 - 23:01:10 EST


Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in tcp_tsq_handler

------------[ cut here ]------------
!lockdep_sock_is_held(sk) && debug_locks
WARNING: ./include/net/sock.h:1799 at sock_owned_by_me include/net/sock.h:1799 [inline], CPU#0: kworker/0:0/9
WARNING: ./include/net/sock.h:1799 at sock_owned_by_user include/net/sock.h:1812 [inline], CPU#0: kworker/0:0/9
WARNING: ./include/net/sock.h:1799 at tcp_tsq_handler+0x1a6/0x200 net/ipv4/tcp_output.c:1292, CPU#0: kworker/0:0/9
Modules linked in:
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: wg-crypt-wg0 wg_packet_tx_worker
RIP: 0010:sock_owned_by_me include/net/sock.h:1799 [inline]
RIP: 0010:sock_owned_by_user include/net/sock.h:1812 [inline]
RIP: 0010:tcp_tsq_handler+0x1a6/0x200 net/ipv4/tcp_output.c:1292
Code: 00 97 96 01 e8 fb 15 79 f7 be 02 00 00 00 eb 0a e8 ef 15 79 f7 be 01 00 00 00 4c 89 ff e8 a2 7f 8e fa eb d0 e8 db 15 79 f7 90 <0f> 0b 90 e9 fd fe ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 07
RSP: 0018:ffffc90000007bb0 EFLAGS: 00010246
RAX: ffffffff8a4e9ad5 RBX: ffff88805ab935d0 RCX: ffff88801defddc0
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000100 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f64 R12: dffffc0000000000
R13: ffffc90000007c20 R14: ffff88805ab93400 R15: ffff88805ab93400
FS: 0000000000000000(0000) GS:ffff888124ce0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe3b037048 CR3: 000000000eb48000 CR4: 00000000003526f0
Call Trace:
<IRQ>
tcp_tsq_workfn+0x384/0x410 net/ipv4/tcp_output.c:1325
process_one_work kernel/workqueue.c:3387 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
bh_worker+0x451/0x870 kernel/workqueue.c:3773
tasklet_action+0xc/0x70 kernel/softirq.c:997
handle_softirqs+0x226/0x860 kernel/softirq.c:645
do_softirq+0x77/0xd0 kernel/softirq.c:546
</IRQ>
<TASK>
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
wg_socket_send_skb_to_peer+0x16b/0x1d0 drivers/net/wireguard/socket.c:183
wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
wg_packet_tx_worker+0x1c8/0x7e0 drivers/net/wireguard/send.c:276
process_one_work kernel/workqueue.c:3387 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
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>


Tested on:

commit: 73e3f071 Merge tag 'nfs-for-7.3-1' of git://git.linux-..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15425625580000
kernel config: https://syzkaller.appspot.com/x/.config?x=22381429a4c2735a
dashboard link: https://syzkaller.appspot.com/bug?extid=2d770620059281e225a4
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
patch: https://syzkaller.appspot.com/x/patch.diff?x=10bb399e580000