------------[ cut here ]------------ WARNING: CPU: 0 PID: 7624 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: 7624 Comm: syz.1.378 Not tainted 6.15.0-rc4-syzkaller-00208-g00b827f0cffa #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:vkms_get_vblank_timestamp+0x167/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:97 Code: c6 fb e8 ac 6e b4 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 3a 89 c6 fb 90 <0f> 0b 90 eb b5 e8 4f 0b 2b fc e9 dc fe ff ff e8 d5 0b 2b fc e9 14 RSP: 0018:ffffc90003177290 EFLAGS: 00010287 RAX: 0000000000000c99 RBX: ffff888023930028 RCX: ffffc90027849000 RDX: 0000000000080000 RSI: ffffffff85f42396 RDI: 0000000000000006 RBP: 0000002b1ff6c90e R08: 0000000000000006 R09: 0000002b1ff6c90e R10: 0000002b1ff6c90e R11: 0000000000000000 R12: ffffc900031773f8 R13: 0000002b1ff6c90e R14: 0000000000004e20 R15: ffffffff85f42230 FS: 0000000000000000(0000) GS:ffff8880977ec000(0063) knlGS:00000000f50b4b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000080202000 CR3: 0000000028db3000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1208 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:237 [inline] __drm_fb_helper_restore_fbdev_mode_unlocked+0x19f/0x200 drivers/gpu/drm/drm_fb_helper.c:216 drm_fb_helper_set_par+0xd8/0x120 drivers/gpu/drm/drm_fb_helper.c:1359 fb_set_var+0x838/0x11f0 drivers/video/fbdev/core/fbmem.c:312 do_fb_ioctl+0x745/0x7e0 drivers/video/fbdev/core/fb_chrdev.c:90 fb_compat_ioctl+0x55e/0x670 drivers/video/fbdev/core/fb_chrdev.c:293 __do_compat_sys_ioctl fs/ioctl.c:1004 [inline] __se_compat_sys_ioctl fs/ioctl.c:947 [inline] __ia32_compat_sys_ioctl+0x24c/0x360 fs/ioctl.c:947 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fd6579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f50b455c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000004601 RDX: 0000000080000380 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi