[moderation] [batman?] BUG: workqueue leaked atomic, lock or RCU: kworker/u8:NUM[NUM]

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d7b8f8e20813 Linux 6.16-rc5
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=122f9582580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f51185bd4f40ad44
dashboard link: https://syzkaller.appspot.com/bug?extid=cdeea8f7401cc1df85ee
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
CC: [ant...@mandelbit.com b.a.t...@lists.open-mesh.org da...@davemloft.net edum...@google.com ho...@kernel.org ku...@kernel.org linux-...@vger.kernel.org marek....@mailbox.org net...@vger.kernel.org pab...@redhat.com sv...@narfation.org s...@simonwunderlich.de]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f933e0e4a6c5/disk-d7b8f8e2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a82be954c91b/vmlinux-d7b8f8e2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/66dbc3de1264/bzImage-d7b8f8e2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cdeea8...@syzkaller.appspotmail.com

BUG: workqueue leaked atomic, lock or RCU: kworker/u8:19[16055]
preempt=0x00000101 lock=2->0 RCU=0->0 workfn=usb_giveback_urb_bh
INFO: lockdep is turned off.
CPU: 1 UID: 0 PID: 16055 Comm: kworker/u8:19 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
process_one_work+0x11f5/0x1b70 kernel/workqueue.c:3259
process_scheduled_works kernel/workqueue.c:3321 [inline]
bh_worker+0x5a4/0x8a0 kernel/workqueue.c:3581
workqueue_softirq_action+0x143/0x1a0 kernel/workqueue.c:3608
tasklet_action+0x14/0x70 kernel/softirq.c:854
handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
do_softirq kernel/softirq.c:480 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:467
</IRQ>
<TASK>
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x1d4/0x3a0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x921/0x1030 net/batman-adv/network-coding.c:720
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.