Hello, syzbot found the following issue on: HEAD commit: d2b6f8a1 Merge tag 'xfs-5.13-merge-3' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12c5b2c3d00000 kernel config: https://syzkaller.appspot.com/x/.config?x=65c207250bba4efe dashboard link: https://syzkaller.appspot.com/bug?extid=6f7fe2dbc479dca0ed17 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6f7fe2dbc479dca0ed17@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ platform vkms: vblank wait timed out on crtc 0 WARNING: CPU: 0 PID: 11785 at drivers/gpu/drm/drm_vblank.c:1269 drm_wait_one_vblank+0x2be/0x500 drivers/gpu/drm/drm_vblank.c:1269 Modules linked in: CPU: 0 PID: 11785 Comm: syz-executor.0 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:drm_wait_one_vblank+0x2be/0x500 drivers/gpu/drm/drm_vblank.c:1269 Code: 85 f6 0f 84 a3 01 00 00 e8 6f f0 32 fd 4c 89 ef e8 97 68 13 00 44 89 e1 4c 89 f2 48 c7 c7 e0 eb d6 89 48 89 c6 e8 57 35 86 04 <0f> 0b e9 87 fe ff ff e8 46 f0 32 fd 31 ff 4c 89 ee e8 5c f8 32 fd RSP: 0018:ffffc90008f7fb40 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 00000000000038f8 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815c7bd5 RDI: fffff520011eff5a RBP: ffff8881437b0000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815c1a3e R11: 0000000000000000 R12: 0000000000000000 R13: ffff88801a1c4010 R14: ffff8880161746b8 R15: ffff888142ddc830 FS: 00007f8eba6e2700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000014a53ad CR3: 0000000021583000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: drm_fb_helper_ioctl+0x159/0x1a0 drivers/gpu/drm/drm_fb_helper.c:1197 do_fb_ioctl+0x1d5/0x690 drivers/video/fbdev/core/fbmem.c:1171 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8eba6e2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000040044620 RDI: 0000000000000006 RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 0000000000a9fb1f R14: 00007f8eba6e2300 R15: 0000000000022000 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.