[syzbot] [net?] [nfc?] WARNING: locking bug in nci_close_device (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: dbf8fe85a16a Merge tag 'net-6.19-rc4' of git://git.kernel...
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=109dffb4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=a94030c847137a18
dashboard link: https://syzkaller.appspot.com/bug?extid=f9c5fd1a0874f9069dce
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/9dc5ccb3a40b/disk-dbf8fe85.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7b9d75d2c0c2/vmlinux-dbf8fe85.xz
kernel image: https://storage.googleapis.com/syzbot-assets/37f71f0365c9/bzImage-dbf8fe85.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f9c5fd...@syzkaller.appspotmail.com

Bluetooth: hci1: Opcode 0x0c1a failed: -4
Bluetooth: hci1: Error when powering off device on rfkill (-4)
Bluetooth: hci2: Opcode 0x0c1a failed: -4
Bluetooth: hci2: Error when powering off device on rfkill (-4)
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#1: syz.6.5778/26216
WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU#1: syz.6.5778/26216
WARNING: kernel/locking/lockdep.c:238 at __lock_acquire+0x39e/0x2cf0 kernel/locking/lockdep.c:5187, CPU#1: syz.6.5778/26216
Modules linked in:
CPU: 1 UID: 0 PID: 26216 Comm: syz.6.5778 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:238 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4854 [inline]
RIP: 0010:__lock_acquire+0x3a5/0x2cf0 kernel/locking/lockdep.c:5187
Code: 17 00 4c 8b 74 24 08 75 27 90 e8 e6 94 ec 02 85 c0 74 1c 83 3d 2f 5d e4 0d 00 75 13 48 8d 3d 42 72 e7 0d 48 c7 c6 3a 0c 87 8d <67> 48 0f b9 3a 90 31 c0 0f b6 98 c4 00 00 00 41 8b 45 20 25 ff 1f
RSP: 0018:ffffc9000c037680 EFLAGS: 00010046
RAX: 0000000000000001 RBX: 0000000000040000 RCX: 0000000000080000
RDX: ffffc90004e52000 RSI: ffffffff8d870c3a RDI: ffffffff8f8567c0
RBP: 0000000000000003 R08: ffffffff8f8252a3 R09: 1ffffffff1f04a54
R10: dffffc0000000000 R11: fffffbfff1f04a55 R12: 00000000000011bb
R13: ffff888052a6aa28 R14: ffff888052a69e80 R15: ffff888052a6a9b0
FS: 00007f462b1636c0(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000028c0 CR3: 00000000765dc000 CR4: 00000000003526f0
Call Trace:
<TASK>
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:3940
__flush_workqueue+0x121/0x14b0 kernel/workqueue.c:3982
nci_close_device+0x2e5/0x610 net/nfc/nci/core.c:567
nci_dev_down+0x3b/0x50 net/nfc/nci/core.c:639
nfc_dev_down+0x152/0x290 net/nfc/core.c:161
nfc_rfkill_set_block+0x2d/0x100 net/nfc/core.c:179
rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346
rfkill_fop_write+0x44b/0x570 net/rfkill/core.c:1301
vfs_write+0x27e/0xb30 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f462a38f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f462b163038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f462a5e6090 RCX: 00007f462a38f749
RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000006
RBP: 00007f462a413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f462a5e6128 R14: 00007f462a5e6090 R15: 00007ffea1921d88
</TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 00 4c 8b 74 add %cl,0x74(%rbx,%rcx,4)
4: 24 08 and $0x8,%al
6: 75 27 jne 0x2f
8: 90 nop
9: e8 e6 94 ec 02 call 0x2ec94f4
e: 85 c0 test %eax,%eax
10: 74 1c je 0x2e
12: 83 3d 2f 5d e4 0d 00 cmpl $0x0,0xde45d2f(%rip) # 0xde45d48
19: 75 13 jne 0x2e
1b: 48 8d 3d 42 72 e7 0d lea 0xde77242(%rip),%rdi # 0xde77264
22: 48 c7 c6 3a 0c 87 8d mov $0xffffffff8d870c3a,%rsi
* 29: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2e: 90 nop
2f: 31 c0 xor %eax,%eax
31: 0f b6 98 c4 00 00 00 movzbl 0xc4(%rax),%ebx
38: 41 8b 45 20 mov 0x20(%r13),%eax
3c: 25 .byte 0x25
3d: ff 1f lcall *(%rdi)


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