------------[ cut here ]------------
WARNING: CPU: 1 PID: 8373 at drivers/gpu/drm/vkms/vkms_crtc.c:97 vkms_get_vblank_timestamp+0x104/0x15c drivers/gpu/drm/vkms/vkms_crtc.c:97
Modules linked in:
CPU: 1 UID: 0 PID: 8373 Comm: syz.4.350 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : vkms_get_vblank_timestamp+0x104/0x15c drivers/gpu/drm/vkms/vkms_crtc.c:97
lr : vkms_get_vblank_timestamp+0x104/0x15c drivers/gpu/drm/vkms/vkms_crtc.c:97
sp : ffff8000a3337580
x29: ffff8000a3337580 x28: 1fffe00018da1c38 x27: ffff0000c6d0e080
x26: ffff8000a33375c0 x25: 1ffff00014666eb8 x24: 1ffff00014666edc
x23: dfff800000000000 x22: 00000011157f82ea x21: 00000011157f82ea
x20: ffff0000ca370080 x19: ffff8000a33376e0 x18: 1fffe000337dfe90
x17: ffff80008f57e000 x16: ffff800082de95c8 x15: 0000000000000002
x14: 1fffe0001ebce721 x13: 0000000000000000 x12: ffff80009ff59000
x11: 0000000000080000 x10: 00000000000161d0 x9 : ffff8000a79a7000
x8 : 00000000000161d1 x7 : 0000000000000000 x6 : ffff80009ff59000
x5 : ffff0000f5e73918 x4 : ffff0000f5e738d8 x3 : 0000000000000000
x2 : ffff8000a33376e0 x1 : 00000011157f82ea x0 : 00000011157f82ea
Call trace:
 vkms_get_vblank_timestamp+0x104/0x15c drivers/gpu/drm/vkms/vkms_crtc.c:97 (P)
 drm_crtc_get_last_vbltimestamp drivers/gpu/drm/drm_vblank.c:879 [inline]
 drm_crtc_next_vblank_start+0x1b8/0x380 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+0x1a0/0x78c drivers/gpu/drm/drm_atomic_helper.c:1765
 drm_atomic_helper_commit+0x4d0/0x8cc drivers/gpu/drm/drm_atomic_helper.c:2194
 drm_atomic_commit+0x204/0x25c drivers/gpu/drm/drm_atomic.c:1577
 drm_client_modeset_commit_atomic+0x524/0x6ac drivers/gpu/drm/drm_client_modeset.c:1103
 drm_client_modeset_commit_locked+0xd0/0x4a0 drivers/gpu/drm/drm_client_modeset.c:1206
 drm_client_modeset_commit+0x50/0x7c 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 drivers/gpu/drm/drm_fb_helper.c:268 [inline]
 drm_fb_helper_lastclose+0x90/0x188 drivers/gpu/drm/drm_fb_helper.c:1986
 drm_fbdev_client_restore+0x3c/0x50 drivers/gpu/drm/clients/drm_fbdev_client.c:31
 drm_client_dev_restore+0x120/0x238 drivers/gpu/drm/drm_client_event.c:117
 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
 drm_release+0x2f8/0x3e0 drivers/gpu/drm/drm_file.c:441
 __fput+0x340/0x75c fs/file_table.c:468
 ____fput+0x20/0x58 fs/file_table.c:496
 task_work_run+0x1dc/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xfc/0x178 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
 el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
irq event stamp: 9538
hardirqs last  enabled at (9537): [<ffff80008adef224>] irqentry_exit+0xd8/0x108 kernel/entry/common.c:214
hardirqs last disabled at (9538): [<ffff80008ade9670>] el1_brk64+0x20/0x54 arch/arm64/kernel/entry-common.c:434
softirqs last  enabled at (8504): [<ffff8000801f95fc>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (8502): [<ffff8000801f95c8>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---