------------[ 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#0: syz.0.0/5322 WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12e2/0x1550 kernel/locking/mutex.c:821, CPU#0: syz.0.0/5322 Modules linked in: CPU: 0 UID: 0 PID: 5322 Comm: syz.0.0 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 RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:625 [inline] RIP: 0010:__mutex_lock+0x12e9/0x1550 kernel/locking/mutex.c:821 Code: 73 7a 90 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 47 02 00 00 83 3d ab 32 92 04 00 75 13 48 8d 3d ae 2e 95 04 48 c7 c6 60 10 0d 8c <67> 48 0f b9 3a 90 e9 6b ee ff ff 90 0f 0b 90 e9 3e f2 ff ff 90 0f RSP: 0018:ffffc9000e097ae0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff88803ef34b00 RDX: 0000000000000000 RSI: ffffffff8c0d1060 RDI: ffffffff907d6f90 RBP: ffffc9000e097c80 R08: ffffffff907a7383 R09: 1ffffffff20f4e70 R10: dffffc0000000000 R11: fffffbfff20f4e71 R12: ffff888034e751c0 R13: 0000000000000000 R14: 1ffff92001c12f70 R15: 0000000000000000 FS: 0000555582ed7540(0000) GS:ffff88808c2ca000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f23503909c0 CR3: 000000003fd1f000 CR4: 0000000000352ef0 Call Trace: virtio_gpu_remove_from_restore_list drivers/gpu/drm/virtio/virtgpu_object.c:70 [inline] virtio_gpu_free_object+0x90/0x1d0 drivers/gpu/drm/virtio/virtgpu_object.c:106 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_client_buffer_delete+0x183/0x2d0 drivers/gpu/drm/drm_client.c:201 drm_fbdev_shmem_fb_destroy+0xb5/0xe0 drivers/gpu/drm/drm_fbdev_shmem.c:67 fb_release+0x11d/0x140 drivers/video/fbdev/core/fb_chrdev.c:381 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f83b379e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff07aabc18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f83b3a27da0 RCX: 00007f83b379e159 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f83b3a27da0 R08: 00007f83b3a26038 R09: 0000000000000000 R10: 0000000000ddcf40 R11: 0000000000000246 R12: 000000000001a316 R13: 00007f83b3a2609c R14: 000000000001978f R15: 00007f83b3a26090 ---------------- Code disassembly (best guess): 0: 73 7a jae 0x7c 2: 90 nop 3: 48 c1 e8 03 shr $0x3,%rax 7: 0f b6 04 18 movzbl (%rax,%rbx,1),%eax b: 84 c0 test %al,%al d: 0f 85 47 02 00 00 jne 0x25a 13: 83 3d ab 32 92 04 00 cmpl $0x0,0x49232ab(%rip) # 0x49232c5 1a: 75 13 jne 0x2f 1c: 48 8d 3d ae 2e 95 04 lea 0x4952eae(%rip),%rdi # 0x4952ed1 23: 48 c7 c6 60 10 0d 8c mov $0xffffffff8c0d1060,%rsi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 90 nop 30: e9 6b ee ff ff jmp 0xffffeea0 35: 90 nop 36: 0f 0b ud2 38: 90 nop 39: e9 3e f2 ff ff jmp 0xfffff27c 3e: 90 nop 3f: 0f .byte 0xf