syzbot

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WARNING: CPU: 0 PID: 4512 at drivers/gpu/drm/vkms/vkms_crtc.c:103 vkms_get_vblank_timestamp+0x184/0x1d0 drivers/gpu/drm/vkms/vkms_crtc.c:103
Modules linked in:
CPU: 0 PID: 4512 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:vkms_get_vblank_timestamp+0x184/0x1d0 drivers/gpu/drm/vkms/vkms_crtc.c:103
Code: 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 e1 7c d3 fc 4c 89 33 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 fc 4a 83 fc <0f> 0b eb ea 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c ba fe ff ff 4c
RSP: 0018:ffffc900038274e8 EFLAGS: 00010093
RAX: ffffffff84fd94d4 RBX: ffffc90003827590 RCX: ffff888026a8d940
RDX: 0000000000000000 RSI: 0000001753f9aa34 RDI: 0000001753f9aa34
RBP: 1ffff92000704eb2 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000704ea0 R11: 1ffff92000704ea0 R12: 0000001753f9aa34
R13: dffffc0000000000 R14: ffff888142ff0000 R15: 0000001753f9aa34
FS:  0000555587709500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000011c0 CR3: 000000002447f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drm_get_last_vbltimestamp drivers/gpu/drm/drm_vblank.c:881 [inline]
 drm_update_vblank_count+0x28b/0x910 drivers/gpu/drm/drm_vblank.c:303
 drm_crtc_accurate_vblank_count+0x109/0x360 drivers/gpu/drm/drm_vblank.c:416
 drm_crtc_arm_vblank_event+0xbf/0x210 drivers/gpu/drm/drm_vblank.c:1066
 vkms_crtc_atomic_flush+0x112/0x1c0 drivers/gpu/drm/vkms/vkms_crtc.c:259
 drm_atomic_helper_commit_planes+0x888/0x990 drivers/gpu/drm/drm_atomic_helper.c:2760
 vkms_atomic_commit_tail+0x5a/0x200 drivers/gpu/drm/vkms/vkms_drv.c:73
 commit_tail+0x27a/0x390 drivers/gpu/drm/drm_atomic_helper.c:1831
 drm_atomic_helper_commit+0x6d3/0x730 drivers/gpu/drm/drm_atomic_helper.c:2071
 drm_atomic_commit+0x248/0x2a0 drivers/gpu/drm/drm_atomic.c:1452
 drm_atomic_helper_set_config+0xde/0x150 drivers/gpu/drm/drm_atomic_helper.c:3204
 drm_mode_setcrtc+0x934/0x15f0 drivers/gpu/drm/drm_crtc.c:886
 drm_ioctl_kernel+0x34d/0x4b0 drivers/gpu/drm/drm_ioctl.c:788
 drm_ioctl+0x610/0x990 drivers/gpu/drm/drm_ioctl.c:891
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5cf0d8f749
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:00007ffd9ba9c628 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5cf0fe5fa0 RCX: 00007f5cf0d8f749
RDX: 00002000000011c0 RSI: 00000000c06864a2 RDI: 0000000000000004
RBP: 00007f5cf0e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5cf0fe5fa0 R14: 00007f5cf0fe5fa0 R15: 0000000000000003
 </TASK>