------------[ cut here ]------------
[CRTC:37:crtc-0] vblank wait timed out
WARNING: drivers/gpu/drm/drm_atomic_helper.c:1927 at drm_atomic_helper_wait_for_vblanks.part.0+0x733/0x890 drivers/gpu/drm/drm_atomic_helper.c:1927, CPU#3: syz.2.543/7538
Modules linked in:
CPU: 3 UID: 0 PID: 7538 Comm: syz.2.543 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:drm_atomic_helper_wait_for_vblanks.part.0+0x739/0x890 drivers/gpu/drm/drm_atomic_helper.c:1927
Code: 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 04 01 84 c0 74 08 3c 03 0f 8e 44 01 00 00 48 8d 3d 0d 06 8a 0c 8b b3 d0 00 00 00 <67> 48 0f b9 3a e9 e1 fc ff ff e8 78 5d 21 fc e9 7c fe ff ff e8 3e
RSP: 0000:ffffc9000c47f690 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888027ac1368 RCX: 1ffff11004f58287
RDX: ffff888027447cc0 RSI: 0000000000000025 RDI: ffffffff927684a0
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880271cd600
FS:  0000000000000000(0000) GS:ffff888095579000(0063) knlGS:00000000f53b6b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f731c080 CR3: 00000000729db000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 drm_atomic_helper_wait_for_vblanks drivers/gpu/drm/drm_atomic_helper.c:1901 [inline]
 drm_atomic_helper_commit_tail+0xff/0x130 drivers/gpu/drm/drm_atomic_helper.c:2003
 commit_tail.isra.0+0x33e/0x420 drivers/gpu/drm/drm_atomic_helper.c:2080
 drm_atomic_helper_commit+0x303/0x380 drivers/gpu/drm/drm_atomic_helper.c:2318
 drm_atomic_commit+0x230/0x300 drivers/gpu/drm/drm_atomic.c:1883
 drm_atomic_helper_set_config+0x13a/0x190 drivers/gpu/drm/drm_atomic_helper.c:3529
 drm_mode_setcrtc+0xeca/0x1d50 drivers/gpu/drm/drm_crtc.c:891
 drm_ioctl_kernel+0x1f3/0x3e0 drivers/gpu/drm/drm_ioctl.c:817
 drm_ioctl+0x5e6/0xc60 drivers/gpu/drm/drm_ioctl.c:914
 drm_compat_ioctl+0x386/0x4c0 drivers/gpu/drm/drm_ioc32.c:381
 __do_compat_sys_ioctl fs/ioctl.c:695 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:638 [inline]
 __ia32_compat_sys_ioctl+0x2cf/0x360 fs/ioctl.c:638
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f08fbc
Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8
RSP: 002b:00000000f53b650c EFLAGS: 00000292 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000c06864a2
RDX: 0000000080000700 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 fc                	add    %bh,%ah
   4:	ff                   	lcall  (bad)
   5:	df 48 89             	fisttps -0x77(%rax)
   8:	f9                   	stc
   9:	48 c1 e9 03          	shr    $0x3,%rcx
   d:	0f b6 04 01          	movzbl (%rcx,%rax,1),%eax
  11:	84 c0                	test   %al,%al
  13:	74 08                	je     0x1d
  15:	3c 03                	cmp    $0x3,%al
  17:	0f 8e 44 01 00 00    	jle    0x161
  1d:	48 8d 3d 0d 06 8a 0c 	lea    0xc8a060d(%rip),%rdi        # 0xc8a0631
  24:	8b b3 d0 00 00 00    	mov    0xd0(%rbx),%esi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 e1 fc ff ff       	jmp    0xfffffd15
  34:	e8 78 5d 21 fc       	call   0xfc215db1
  39:	e9 7c fe ff ff       	jmp    0xfffffeba
  3e:	e8                   	.byte 0xe8
  3f:	3e                   	ds