------------[ cut here ]------------
WARNING: CPU: 0 PID: 19738 at drivers/gpu/drm/vkms/vkms_crtc.c:97 vkms_get_vblank_timestamp+0x167/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:97
Modules linked in:
CPU: 0 UID: 0 PID: 19738 Comm: syz.7.2368 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:vkms_get_vblank_timestamp+0x167/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:97
Code: ee fb e8 fc 06 dc fb 4c 89 e1 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 75 43 49 89 04 24 eb c0 e8 4a b0 ee fb 90 <0f> 0b 90 eb b5 e8 6f 31 56 fc e9 dc fe ff ff e8 f5 31 56 fc e9 14
RSP: 0018:ffffc900035077e8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888142340028 RCX: ffffffff85cc621e
RDX: ffff888044f18000 RSI: ffffffff85cc6296 RDI: 0000000000000006
RBP: 000001728239aa7a R08: 0000000000000006 R09: 000001728239aa7a
R10: 000001728239aa7a R11: 0000000000000000 R12: ffffc90003507950
R13: 000001728239aa7a R14: 0000000000004e20 R15: ffffffff85cc6130
FS:  000055558a86e500(0000) GS:ffff888124e6a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa2dacc87d0 CR3: 0000000063e17000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 drm_crtc_get_last_vbltimestamp+0x105/0x1b0 drivers/gpu/drm/drm_vblank.c:879
 drm_crtc_next_vblank_start+0x182/0x300 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+0x203/0x830 drivers/gpu/drm/drm_atomic_helper.c:1765
 drm_atomic_helper_commit+0x1cf/0x380 drivers/gpu/drm/drm_atomic_helper.c:2194
 drm_atomic_commit+0x234/0x300 drivers/gpu/drm/drm_atomic.c:1577
 drm_client_modeset_commit_atomic+0x69d/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1103
 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1206
 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1232
 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:238 [inline]
 __drm_fb_helper_restore_fbdev_mode_unlocked+0x19f/0x200 drivers/gpu/drm/drm_fb_helper.c:217
 drm_fbdev_client_restore+0x2c/0x40 drivers/gpu/drm/clients/drm_fbdev_client.c:31
 drm_client_dev_restore+0x1f6/0x2a0 drivers/gpu/drm/drm_client_event.c:117
 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
 drm_release+0x2c4/0x360 drivers/gpu/drm/drm_file.c:441
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/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_syscall_64+0x419/0x4e0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3d5058eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd3b61d568 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f3d507e7da0 RCX: 00007f3d5058eec9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f3d507e7da0 R08: 0000000000000a78 R09: 000000163b61d85f
R10: 00007f3d507e7cb0 R11: 0000000000000246 R12: 000000000018469a
R13: 00007f3d507e6090 R14: ffffffffffffffff R15: 00007ffd3b61d680
 </TASK>