------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline], CPU#2: kworker/2:1/151
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x944/0x1bd0 kernel/locking/mutex.c:821, CPU#2: kworker/2:1/151
Modules linked in:
CPU: 2 UID: 0 PID: 151 Comm: kworker/2:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events delayed_fput
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x94b/0x1bd0 kernel/locking/mutex.c:821
Code: 0f b6 14 11 38 d0 7c 08 84 d2 0f 85 c0 10 00 00 44 8b 05 88 3f 73 05 45 85 c0 75 13 48 8d 3d 8c 4a 76 05 48 c7 c6 c0 f4 ef 8b <67> 48 0f b9 3a 90 e9 1b f8 ff ff 4d 8d a7 f0 0a 00 00 4c 89 e7 e8
RSP: 0018:ffffc90002737900 EFLAGS: 00010246
RAX: 0000000000000003 RBX: ffff888037f151c0 RCX: 1ffffffff228a8a0
RDX: 0000000000000000 RSI: ffffffff8beff4c0 RDI: ffffffff91485010
RBP: ffffc90002737a70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000762b R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888027d92b60
FS:  0000000000000000(0000) GS:ffff8880d5d5d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2745c2 CR3: 0000000035d51000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 virtio_gpu_remove_from_restore_list drivers/gpu/drm/virtio/virtgpu_object.c:70 [inline]
 virtio_gpu_free_object+0xec/0x280 drivers/gpu/drm/virtio/virtgpu_object.c:106
 drm_gem_object_free+0x60/0xa0 drivers/gpu/drm/drm_gem.c:1164
 kref_put include/linux/kref.h:65 [inline]
 __drm_gem_object_put include/drm/drm_gem.h:562 [inline]
 drm_gem_object_put include/drm/drm_gem.h:575 [inline]
 drm_gem_object_put include/drm/drm_gem.h:572 [inline]
 drm_gem_dmabuf_release+0xd1/0xf0 drivers/gpu/drm/drm_prime.c:272
 dma_buf_release+0x159/0x2d0 drivers/dma-buf/dma-buf.c:183
 dentry_kill+0x2ce/0xc20 fs/dcache.c:831
 finish_dput fs/dcache.c:1001 [inline]
 dput.part.0+0xd7/0x240 fs/dcache.c:1042
 dput+0x1f/0x30 fs/dcache.c:1037
 __fput+0x519/0xb50 fs/file_table.c:520
 delayed_fput+0x72/0x90 fs/file_table.c:535
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	0f b6 14 11          	movzbl (%rcx,%rdx,1),%edx
   4:	38 d0                	cmp    %dl,%al
   6:	7c 08                	jl     0x10
   8:	84 d2                	test   %dl,%dl
   a:	0f 85 c0 10 00 00    	jne    0x10d0
  10:	44 8b 05 88 3f 73 05 	mov    0x5733f88(%rip),%r8d        # 0x5733f9f
  17:	45 85 c0             	test   %r8d,%r8d
  1a:	75 13                	jne    0x2f
  1c:	48 8d 3d 8c 4a 76 05 	lea    0x5764a8c(%rip),%rdi        # 0x5764aaf
  23:	48 c7 c6 c0 f4 ef 8b 	mov    $0xffffffff8beff4c0,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	e9 1b f8 ff ff       	jmp    0xfffff850
  35:	4d 8d a7 f0 0a 00 00 	lea    0xaf0(%r15),%r12
  3c:	4c 89 e7             	mov    %r12,%rdi
  3f:	e8                   	.byte 0xe8