------------[ cut here ]------------
WARNING: CPU: 1 PID: 10842 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: 10842 Comm: syz.4.1316 Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #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: c4 fb e8 dc ae 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 da e3 c4 fb 90 <0f> 0b 90 eb b5 e8 df 5e 2a fc e9 dc fe ff ff e8 65 5f 2a fc e9 14
RSP: 0018:ffffc900038670b8 EFLAGS: 00010283
RAX: 0000000000040c64 RBX: ffff888143398028 RCX: ffffc9000ed13000
RDX: 0000000000080000 RSI: ffffffff85f66c16 RDI: 0000000000000006
RBP: 00000071c4385f1c R08: 0000000000000006 R09: 00000071c4385f1c
R10: 00000071c4385f1c R11: 0000000000000000 R12: ffffc90003867220
R13: 00000071c4385f1c R14: 0000000000004e20 R15: ffffffff85f66ab0
FS:  00007f0c369456c0(0000) GS:ffff888124ab2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b301e8ff8 CR3: 0000000021afc000 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_client_modeset_commit_atomic+0x69d/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1079
 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1182
 pan_display_atomic drivers/gpu/drm/drm_fb_helper.c:1387 [inline]
 drm_fb_helper_pan_display+0x32d/0xa40 drivers/gpu/drm/drm_fb_helper.c:1447
 fb_pan_display+0x479/0x7d0 drivers/video/fbdev/core/fbmem.c:191
 fb_set_var+0x860/0x11f0 drivers/video/fbdev/core/fbmem.c:323
 fbcon_blank+0x674/0xd20 drivers/video/fbdev/core/fbcon.c:2235
 do_unblank_screen+0x27b/0x4c0 drivers/tty/vt/vt.c:4561
 vt_kdsetmode drivers/tty/vt/vt_ioctl.c:276 [inline]
 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:381 [inline]
 vt_ioctl+0x1229/0x2f50 drivers/tty/vt/vt_ioctl.c:751
 tty_ioctl+0x65a/0x1610 drivers/tty/tty_io.c:2802
 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: 0033:0x7f0c35b8e969
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:00007f0c36945038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0c35db6160 RCX: 00007f0c35b8e969
RDX: 0000000000000002 RSI: 0000000000004b3a RDI: 000000000000000c
RBP: 00007f0c35c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0c35db6160 R15: 00007ffd4a7b9898
 </TASK>