[moderation] [arm?] BUG: workqueue leaked atomic, lock or RCU: kworker/u8:NUM[NUM] (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2a4c0c11c019 Merge tag 's390-7.1-1' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16c831ba580000
kernel config: https://syzkaller.appspot.com/x/.config?x=985a509dd8c890d0
dashboard link: https://syzkaller.appspot.com/bug?extid=1c62954c54045eda50cb
compiler: arm-linux-gnueabi-gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: arm
CC: [linux-ar...@lists.infradead.org linux-...@vger.kernel.org li...@armlinux.org.uk]

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/98a89b9f34e4/non_bootable_disk-2a4c0c11.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f56d56b72d87/vmlinux-2a4c0c11.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6d3df722c520/zImage-2a4c0c11.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1c6295...@syzkaller.appspotmail.com

BUG: workqueue leaked atomic, lock or RCU: kworker/u8:7[957]
preempt=0x00000000 lock=0->0 RCU=0->124 workfn=wb_workfn
CPU: 1 UID: 0 PID: 957 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT
Hardware name: ARM-Versatile Express
Workqueue: writeback wb_workfn (flush-253:0)
Call trace:
[<80201a14>] (dump_backtrace) from [<80201b08>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
r7:60000013 r6:60000013 r5:8231c0d0 r4:00000000
[<80201af0>] (show_stack) from [<8021e320>] (__dump_stack lib/dump_stack.c:94 [inline])
[<80201af0>] (show_stack) from [<8021e320>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120)
[<8021e2c4>] (dump_stack_lvl) from [<8021e34c>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
r7:83012a00 r6:83801200 r5:84265554 r4:84127a00
[<8021e334>] (dump_stack) from [<802766a8>] (process_one_work+0x510/0x5a0 kernel/workqueue.c:3323)
[<80276198>] (process_one_work) from [<80277124>] (process_scheduled_works kernel/workqueue.c:3385 [inline])
[<80276198>] (process_one_work) from [<80277124>] (worker_thread+0x16c/0x318 kernel/workqueue.c:3466)
r10:00000000 r9:84127a30 r8:833de200 r7:82a03d80 r6:83012a20 r5:83012a00
r4:84127a00
[<80276fb8>] (worker_thread) from [<8028117c>] (kthread+0x11c/0x154 kernel/kthread.c:436)
r10:00000000 r9:df849e88 r8:844da480 r7:84127a00 r6:80276fb8 r5:833de200
r4:84131f40
[<80281060>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137)
Exception stack(0xe0449fb0 to 0xe0449ff8)
9fa0: 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80281060 r4:84131f40
------------[ cut here ]------------
WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x4ac/0x638 kernel/rcu/tree_plugin.h:332, CPU#1: kworker/u8:7/957
Voluntary context switch within RCU read-side critical section!
Modules linked in:


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