Hello,
syzbot found the following issue on:
HEAD commit: c53f467229a7 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output:
https://syzkaller.appspot.com/x/log.txt?x=16e65b92580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=1f2b6fe1fdf1a00b
dashboard link:
https://syzkaller.appspot.com/bug?extid=16210d09509730207241
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/d09cbe6bb078/disk-c53f4672.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/83e2a6822b1d/vmlinux-c53f4672.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/9eff6dd4ff63/bzImage-c53f4672.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+16210d...@syzkaller.appspotmail.com
------------[ cut here ]------------
rtmutex deadlock detected
WARNING: kernel/locking/rtmutex.c:1674 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674, CPU#0: syz.7.2908/15923
Modules linked in:
CPU: 0 UID: 0 PID: 15923 Comm: syz.7.2908 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674
Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 86 00 00 00 48 89 f7 e8 a6 39 01 00 48 8d 3d af 7c 0a 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1c 25 08 10 b3 91 4c
RSP: 0018:ffffc90004617710 EFLAGS: 00010286
RAX: 0000000080000000 RBX: ffffc900046177a0 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff8ce0bbf9 RDI: ffffffff8ede5760
RBP: ffffc900046178c0 R08: ffffffff8edb3477 R09: 1ffffffff1db668e
R10: dffffc0000000000 R11: fffffbfff1db668f R12: 1ffff920008c2ef0
R13: ffffffff8ad3d599 R14: ffffffff8eb910e0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056422df5abe0 CR3: 000000005929c000 CR4: 00000000003526f0
Call Trace:
<TASK>
__rt_mutex_slowlock kernel/locking/rtmutex.c:1734 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x666/0x6b0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:552
rfkill_unregister+0xd1/0x230 net/rfkill/core.c:1145
nfc_unregister_device+0x96/0x300 net/nfc/core.c:1167
virtual_ncidev_close+0x59/0x90 drivers/nfc/virtual_ncidev.c:172
__fput+0x45b/0xa80 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x694/0x22f0 kernel/exit.c:971
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x125d/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2e7f9af749
Code: Unable to access opcode bytes at 0x7f2e7f9af71f.
RSP: 002b:00007f2e7dc0e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: 0000000000000008 RBX: 00007f2e7fc05fa0 RCX: 00007f2e7f9af749
RDX: 0000000000000002 RSI: 0000200000000500 RDI: ffffffffffffff9c
RBP: 00007f2e7fa33f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2e7fc06038 R14: 00007f2e7fc05fa0 R15: 00007fff5a2e50f8
</TASK>
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 41 57 push %r15
b: 41 56 push %r14
d: 41 55 push %r13
f: 41 54 push %r12
11: 53 push %rbx
12: 83 ff dd cmp $0xffffffdd,%edi
15: 0f 85 86 00 00 00 jne 0xa1
1b: 48 89 f7 mov %rsi,%rdi
1e: e8 a6 39 01 00 call 0x139c9
23: 48 8d 3d af 7c 0a 04 lea 0x40a7caf(%rip),%rdi # 0x40a7cd9
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 4c 8d 3d 00 00 00 00 lea 0x0(%rip),%r15 # 0x36
36: 65 48 8b 1c 25 08 10 mov %gs:0xffffffff91b31008,%rbx
3d: b3 91
3f: 4c rex.WR
---
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