[syzbot] [nfc?] kernel panic: kernel: panic_on_warn set ... (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f9a2394a2348 Merge tag 'mm-hotfixes-stable-2026-08-06-18-4..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11a1be49580000
kernel config: https://syzkaller.appspot.com/x/.config?x=30772517ee66ef58
dashboard link: https://syzkaller.appspot.com/bug?extid=fe5ea83cdd7fc263f452
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ebec1b22682a/disk-f9a2394a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5c88db273365/vmlinux-f9a2394a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/43600cc1b90a/bzImage-f9a2394a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fe5ea8...@syzkaller.appspotmail.com

Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 0 UID: 0 PID: 7451 Comm: kworker/u8:11 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: iou_exit io_ring_exit_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
vpanic+0x552/0x970 kernel/panic.c:651
panic+0xd1/0xe0 kernel/panic.c:788
check_panic_on_warn kernel/panic.c:525 [inline]
check_panic_on_warn.cold+0x19/0x34 kernel/panic.c:520
__warn.cold+0x191/0x318 kernel/panic.c:1104
__report_bug+0x30f/0x440 lib/bug.c:254
report_bug+0xb2/0x220 lib/bug.c:286
handle_bug+0x16a/0x2a0 arch/x86/kernel/traps.c:436
exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:490
asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:593
RIP: 0010:io_ring_exit_work+0x479/0xd7a io_uring/io_uring.c:2365
Code: 8e e8 ab 8c 44 01 48 8b 05 24 97 4b 0d 4c 8b 7c 24 38 31 ff 49 29 c7 4c 89 fe e8 f2 f2 d4 00 4d 85 ff 79 12 e8 48 f8 d4 00 90 <0f> 0b 90 48 c7 44 24 20 70 17 00 00 e8 36 f8 d4 00 48 8b 74 24 20
RSP: 0018:ffffc900047b7aa0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888052290710 RCX: ffffffff81355b6e
RDX: ffff888052140000 RSI: ffffffff81355b78 RDI: ffff888052140000
RBP: ffffc900047b7c38 R08: 0000000000000007 R09: 0000000000000000
R10: fffffffffffffffc R11: 0000000000000000 R12: ffff888052290000
R13: dffffc0000000000 R14: 0000000052290700 R15: fffffffffffffffc
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..


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