[syzbot] WARNING in alloc_workqueue

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    1d67c8d993ba Merge tag 'soc-fixes-5.14-1' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11766c5a300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4743a765b066cc1c
dashboard link: https://syzkaller.appspot.com/bug?extid=1e80b07ec236d945017f

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1e80b07ec236d945017f@xxxxxxxxxxxxxxxxxxxxxxxxx

RBP: 0000000000000005 R08: 0000000000000000 R09: ffffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000004 R14: 0000000020000300 R15: 0000000000000000
------------[ cut here ]------------
WARNING: CPU: 0 PID: 13508 at kernel/locking/lockdep.c:6305 lockdep_unregister_key+0x19a/0x250 kernel/locking/lockdep.c:6305
Modules linked in:
CPU: 0 PID: 13508 Comm: syz-executor.0 Not tainted 5.14.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:lockdep_unregister_key+0x19a/0x250 kernel/locking/lockdep.c:6305
Code: 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 8f 00 00 00 4d 89 7d 08 48 b8 22 01 00 00 00 00 ad de 48 89 43 08 eb 02 <0f> 0b 4c 89 f7 ba 01 00 00 00 48 89 ee e8 44 fd ff ff 4c 89 f7 e8
RSP: 0018:ffffc90001bc78e0 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffffffff1ad8795
RDX: 1ffffffff1fcb30e RSI: 0000000000000004 RDI: ffffffff8fe59870
RBP: ffff88801db52928 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52000378f12 R11: 0000000000000000 R12: 0000000000000246
R13: dffffc0000000000 R14: ffffffff8fcd0868 R15: ffff88801db52820
FS:  00007f7d4ceaa700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7d4cea9f78 CR3: 0000000078c46000 CR4: 0000000000150ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 wq_unregister_lockdep kernel/workqueue.c:3468 [inline]
 alloc_workqueue+0xb31/0xef0 kernel/workqueue.c:4337
 loop_configure+0x4d8/0x1580 drivers/block/loop.c:1199
 lo_ioctl+0x403/0x1600 drivers/block/loop.c:1773
 blkdev_ioctl+0x2a1/0x6d0 block/ioctl.c:585
 block_ioctl+0xf9/0x140 fs/block_dev.c:1602
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x466397
Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 48 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7d4cea9f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004afcc0 RCX: 0000000000466397
RDX: 0000000000000004 RSI: 0000000000004c00 RDI: 0000000000000005
RBP: 0000000000000005 R08: 0000000000000000 R09: ffffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000004 R14: 0000000020000300 R15: 0000000000000000


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