------------[ cut here ]------------
WARNING: CPU: 1 PID: 9504 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: 1 UID: 0 PID: 9504 Comm: syz.2.942 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:vkms_get_vblank_timestamp+0x167/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:97
Code: c5 fb e8 4c e7 b2 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 9a 1b c5 fb 90 <0f> 0b 90 eb b5 e8 6f 81 2a fc e9 dc fe ff ff e8 f5 81 2a fc e9 14
RSP: 0018:ffffc9000b9cf760 EFLAGS: 00010246
RAX: 0000000000080000 RBX: ffff888143740028 RCX: ffffc9000ce3a000
RDX: 0000000000080000 RSI: ffffffff85f62226 RDI: 0000000000000006
RBP: 00000040f34b2a45 R08: 0000000000000006 R09: 00000040f34b2a45
R10: 00000040f34b2a45 R11: 0000000000000000 R12: ffffc9000b9cf8c8
R13: 00000040f34b2a45 R14: 0000000000004e20 R15: ffffffff85f620c0
FS:  00007f6119eb96c0(0000) GS:ffff888124ab3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f06da4d56c0 CR3: 000000002b480000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drm_crtc_get_last_vbltimestamp+0x102/0x1b0 drivers/gpu/drm/drm_vblank.c:878
 drm_crtc_next_vblank_start+0x182/0x300 drivers/gpu/drm/drm_vblank.c:1012
 set_fence_deadline drivers/gpu/drm/drm_atomic_helper.c:1596 [inline]
 drm_atomic_helper_wait_for_fences+0x203/0x830 drivers/gpu/drm/drm_atomic_helper.c:1643
 drm_atomic_helper_commit+0x1cf/0x380 drivers/gpu/drm/drm_atomic_helper.c:2072
 drm_atomic_commit+0x231/0x300 drivers/gpu/drm/drm_atomic.c:1518
 drm_mode_atomic_ioctl+0x1c4e/0x25f0 drivers/gpu/drm/drm_atomic_uapi.c:1540
 drm_ioctl_kernel+0x1f1/0x3e0 drivers/gpu/drm/drm_ioctl.c:796
 drm_ioctl+0x5c9/0xc30 drivers/gpu/drm/drm_ioctl.c:893
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl fs/ioctl.c:892 [inline]
 __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6118f8d169
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:00007f6119eb9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f61191a5fa0 RCX: 00007f6118f8d169
RDX: 0000200000000380 RSI: 00000000c03864bc RDI: 0000000000000005
RBP: 00007f611900e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f61191a5fa0 R15: 00007fff0d3509b8
 </TASK>