From: syzbot <syzbot+72fceb8393e04ce876d9@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
timo.joannin@gmail.com
Subject: Re: [syzbot] possible deadlock in wg_ratelimiter_uninit
Date: Tue, 10 Nov 2026 13:40:03 -0800 [thread overview]
Message-ID: <6af38f33.17ff5aea.1b027f.019c.GAE@google.com> (raw)
In-Reply-To: <20261110171412.287522-1-timo.joannin@gmail.com>
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
possible deadlock in inet_shutdown
block nbd0: Receive control failed (result -32)
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u9:0/53 is trying to acquire lock:
ffff888079910fa0 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1717 [inline]
ffff888079910fa0 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:911
but task is already holding lock:
ffff88807468d668 (&nsock->tx_lock){+.+.}-{4:4}, at: recv_work+0x1cff/0x1e30 drivers/block/nbd.c:1029
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #6 (&nsock->tx_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821
nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
nbd_queue_rq+0x373/0xff0 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2141
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_work_fn+0x167/0x2f0 block/blk-mq.c:2556
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
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
-> #5 (&cmd->lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821
nbd_queue_rq+0xc1/0xff0 drivers/block/nbd.c:1199
blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2141
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_work_fn+0x167/0x2f0 block/blk-mq.c:2556
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
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
-> #4 (set->srcu){.+.+}-{0:0}:
srcu_lock_sync include/linux/srcu.h:261 [inline]
__synchronize_srcu+0xca/0x2f0 kernel/rcu/srcutree.c:1662
elevator_switch+0x1e8/0x7b0 block/elevator.c:576
elevator_change+0x2fa/0x480 block/elevator.c:681
elevator_set_default+0x375/0x440 block/elevator.c:754
blk_register_queue+0x404/0x4f0 block/blk-sysfs.c:992
__add_disk+0x6b8/0xdb0 block/genhd.c:531
add_disk_fwnode+0x100/0x3a0 block/genhd.c:600
add_disk include/linux/blkdev.h:799 [inline]
nbd_dev_add+0x733/0xb60 drivers/block/nbd.c:2026
nbd_init+0x168/0x1f0 drivers/block/nbd.c:2743
do_one_initcall+0x250/0x870 init/main.c:1419
do_initcall_level+0x10a/0x1a0 init/main.c:1481
Tested on:
commit: 067c5c24 Merge tag 'page_alloc-for-7.4-rc2' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=119221a1580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d44b06612b68f56
dashboard link: https://syzkaller.appspot.com/bug?extid=72fceb8393e04ce876d9
compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
patch: https://syzkaller.appspot.com/x/patch.diff?x=113f2fa5580000
next parent reply other threads:[~2026-11-10 21:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20261110171412.287522-1-timo.joannin@gmail.com>
2026-11-10 21:40 ` syzbot [this message]
[not found] <20261111113252.307157-1-timo.joannin@gmail.com>
2026-11-11 20:17 ` [syzbot] possible deadlock in wg_ratelimiter_uninit syzbot
2026-11-05 20:31 syzbot
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