------------[ cut here ]------------
WARNING: CPU: 0 PID: 13367 at drivers/gpu/drm/vkms/vkms_crtc.c:97 vkms_get_vblank_timestamp+0x137/0x160 drivers/gpu/drm/vkms/vkms_crtc.c:97
Modules linked in:
CPU: 0 UID: 0 PID: 13367 Comm: syz.4.2010 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:vkms_get_vblank_timestamp+0x137/0x160 drivers/gpu/drm/vkms/vkms_crtc.c:97
Code: 42 80 3c 28 00 74 08 48 89 df e8 74 6c 66 fc 4c 89 33 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d e9 80 38 8a 05 cc e8 8a a7 00 fc 90 <0f> 0b 90 eb e3 44 89 e1 80 e1 07 38 c1 0f 8c ff fe ff ff 4c 89 e7
RSP: 0018:ffffc9000f5ff6a8 EFLAGS: 00010293
RAX: ffffffff85bf5c26 RBX: ffffc9000f5ff820 RCX: ffff88802fca3c80
RDX: 0000000000000000 RSI: 000000ac4fd39f34 RDI: 000000ac4fd39f34
RBP: 1ffff92001ebff04 R08: ffffc90003aa9000 R09: 0000000000000000
R10: ffffc90003aa9000 R11: ffffffff85bf5af0 R12: 000000ac4fd39f34
R13: dffffc0000000000 R14: ffff888141f98028 R15: 000000ac4fd39f34
FS:  0000000000000000(0000) GS:ffff888126138000(0063) knlGS:0000000057de1440
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7fe55c0 CR3: 000000005233c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 drm_crtc_get_last_vbltimestamp drivers/gpu/drm/drm_vblank.c:879 [inline]
 drm_crtc_next_vblank_start+0x226/0x470 drivers/gpu/drm/drm_vblank.c:1013
 set_fence_deadline drivers/gpu/drm/drm_atomic_helper.c:1718 [inline]
 drm_atomic_helper_wait_for_fences+0x265/0x8c0 drivers/gpu/drm/drm_atomic_helper.c:1765
 drm_atomic_helper_commit+0x5c7/0xb10 drivers/gpu/drm/drm_atomic_helper.c:2194
 drm_atomic_commit+0x262/0x2c0 drivers/gpu/drm/drm_atomic.c:1577
 drm_client_modeset_commit_atomic+0x620/0x760 drivers/gpu/drm/drm_client_modeset.c:1103
 drm_client_modeset_commit_locked+0xcb/0x4d0 drivers/gpu/drm/drm_client_modeset.c:1206
 drm_client_modeset_commit+0x4a/0x70 drivers/gpu/drm/drm_client_modeset.c:1232
 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:236 [inline]
 drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:266 [inline]
 drm_fb_helper_lastclose+0xa4/0x1c0 drivers/gpu/drm/drm_fb_helper.c:1972
 drm_fbdev_client_restore+0x34/0x40 drivers/gpu/drm/clients/drm_fbdev_client.c:31
 drm_client_dev_restore+0x13c/0x270 drivers/gpu/drm/drm_client_event.c:117
 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
 drm_release+0x318/0x3f0 drivers/gpu/drm/drm_file.c:441
 __fput+0x44c/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 __do_fast_syscall_32+0x1f4/0x2b0 arch/x86/entry/syscall_32.c:309
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf702d539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f751faec EFLAGS: 00000206 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   4:	10 07                	adc    %al,(%rdi)
   6:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   a:	10 08                	adc    %cl,(%rax)
   c:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  20:	00 51 52             	add    %dl,0x52(%rcx)
  23:	55                   	push   %rbp
  24:	89 e5                	mov    %esp,%ebp
  26:	0f 34                	sysenter
  28:	cd 80                	int    $0x80
* 2a:	5d                   	pop    %rbp <-- trapping instruction
  2b:	5a                   	pop    %rdx
  2c:	59                   	pop    %rcx
  2d:	c3                   	ret
  2e:	90                   	nop
  2f:	90                   	nop
  30:	90                   	nop
  31:	90                   	nop
  32:	90                   	nop
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop