[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 54.707349][ T26] audit: type=1800 audit(1574831358.701:25): pid=8550 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 54.745145][ T26] audit: type=1800 audit(1574831358.701:26): pid=8550 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 54.779425][ T26] audit: type=1800 audit(1574831358.711:27): pid=8550 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.32' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 70.200676][ T8703] [drm:drm_calc_timestamping_constants] *ERROR* crtc 32: Can't calculate constants, dotclock = 0! [ 70.212115][ C1] ------------[ cut here ]------------ [ 70.217768][ C1] WARNING: CPU: 1 PID: 8703 at drivers/gpu/drm/vkms/vkms_crtc.c:23 vkms_vblank_simulate+0x33a/0x3c0 [ 70.228605][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 70.235175][ C1] CPU: 1 PID: 8703 Comm: syz-executor278 Not tainted 5.4.0-syzkaller #0 [ 70.243492][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 70.253646][ C1] Call Trace: [ 70.256917][ C1] [ 70.259755][ C1] dump_stack+0x197/0x210 [ 70.264067][ C1] ? vkms_vblank_simulate+0x270/0x3c0 [ 70.269420][ C1] panic+0x2e3/0x75c [ 70.273314][ C1] ? add_taint.cold+0x16/0x16 [ 70.277972][ C1] ? printk+0xba/0xed [ 70.281946][ C1] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 70.287381][ C1] ? __warn.cold+0x14/0x35 [ 70.291778][ C1] ? __warn+0xd9/0x1d0 [ 70.295840][ C1] ? vkms_vblank_simulate+0x33a/0x3c0 [ 70.301202][ C1] __warn.cold+0x2f/0x35 [ 70.305439][ C1] ? report_bug.cold+0x63/0xad [ 70.310193][ C1] ? vkms_vblank_simulate+0x33a/0x3c0 [ 70.315543][ C1] report_bug+0x289/0x300 [ 70.319868][ C1] do_error_trap+0x11b/0x200 [ 70.324436][ C1] do_invalid_op+0x37/0x50 [ 70.328833][ C1] ? vkms_vblank_simulate+0x33a/0x3c0 [ 70.334182][ C1] invalid_op+0x23/0x30 [ 70.338316][ C1] RIP: 0010:vkms_vblank_simulate+0x33a/0x3c0 [ 70.344273][ C1] Code: a1 00 00 00 49 8b 94 24 50 02 00 00 4c 89 f1 bf 02 00 00 00 48 c7 c6 a0 a4 03 88 e8 50 89 b5 ff e9 dd fe ff ff e8 b6 6c 7c fd <0f> 0b e9 7e fd ff ff e8 4a aa b8 fd e9 f4 fd ff ff 48 8b 7d d0 e8 [ 70.363854][ C1] RSP: 0018:ffff8880ae909dd0 EFLAGS: 00010006 [ 70.369896][ C1] RAX: ffff8880a85ba080 RBX: ffff8880a38296e8 RCX: ffffffff83f7a145 [ 70.377848][ C1] RDX: 0000000000010000 RSI: ffffffff83f7a3ca RDI: 0000000000000007 [ 70.385799][ C1] RBP: ffff8880ae909e08 R08: ffff8880a85ba080 R09: ffff8880a85ba910 [ 70.393748][ C1] R10: fffffbfff138ed40 R11: ffffffff89c76a07 R12: 0000000000034591 [ 70.401710][ C1] R13: ffff8880a3829740 R14: ffff8880a3828be8 R15: 0000000000000000 [ 70.409690][ C1] ? vkms_vblank_simulate+0xb5/0x3c0 [ 70.414969][ C1] ? vkms_vblank_simulate+0x33a/0x3c0 [ 70.420508][ C1] __hrtimer_run_queues+0x364/0xe40 [ 70.425699][ C1] ? vkms_disable_vblank+0x20/0x20 [ 70.430793][ C1] ? hrtimer_init+0x330/0x330 [ 70.435460][ C1] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 70.441167][ C1] ? ktime_get_update_offsets_now+0x2d3/0x440 [ 70.447218][ C1] hrtimer_interrupt+0x314/0x770 [ 70.452155][ C1] smp_apic_timer_interrupt+0x160/0x610 [ 70.457681][ C1] apic_timer_interrupt+0xf/0x20 [ 70.462589][ C1] [ 70.465512][ C1] RIP: 0010:_raw_spin_unlock_irqrestore+0x95/0xe0 [ 70.471904][ C1] Code: 48 c7 c0 60 2f f3 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d 62 8a 9c 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 9c 58 f9 f9 65 8b 05 ed 58 ab 78 [ 70.491485][ C1] RSP: 0018:ffff888095c47920 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 [ 70.499875][ C1] RAX: 1ffffffff11e65ec RBX: 0000000000000286 RCX: 0000000000000000 [ 70.507839][ C1] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: 0000000000000286 [ 70.515791][ C1] RBP: ffff888095c47930 R08: ffff8880a85ba080 R09: 0000000000000000 [ 70.523742][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a38282f0 [ 70.531690][ C1] R13: 0000000000000000 R14: ffff8880a38282f0 R15: ffff8880a3fad508 [ 70.539659][ C1] drm_vblank_get+0x150/0x1e0 [ 70.544314][ C1] drm_wait_vblank_ioctl+0x51a/0x1990 [ 70.549665][ C1] ? drm_dev_exit+0x22/0x60 [ 70.554150][ C1] ? drm_legacy_modeset_ctl_ioctl+0x4a0/0x4a0 [ 70.560193][ C1] ? lock_downgrade+0x920/0x920 [ 70.565029][ C1] ? lock_acquire+0x190/0x410 [ 70.569693][ C1] ? drm_dev_alloc+0xd0/0xd0 [ 70.576089][ C1] drm_ioctl_kernel+0x244/0x300 [ 70.580916][ C1] ? drm_legacy_modeset_ctl_ioctl+0x4a0/0x4a0 [ 70.586962][ C1] ? drm_setversion+0x8c0/0x8c0 [ 70.591792][ C1] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 70.598013][ C1] ? _copy_from_user+0x12c/0x1a0 [ 70.602930][ C1] drm_ioctl+0x54e/0xa60 [ 70.607167][ C1] ? drm_legacy_modeset_ctl_ioctl+0x4a0/0x4a0 [ 70.613212][ C1] ? drm_ioctl_kernel+0x300/0x300 [ 70.618213][ C1] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 70.624022][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 70.630261][ C1] ? drm_ioctl_kernel+0x300/0x300 [ 70.635271][ C1] do_vfs_ioctl+0xdb6/0x13e0 [ 70.639847][ C1] ? ioctl_preallocate+0x210/0x210 [ 70.645108][ C1] ? kmem_cache_free+0x26b/0x320 [ 70.650250][ C1] ? putname+0xf4/0x130 [ 70.654391][ C1] ? do_sys_open+0x31d/0x5d0 [ 70.658966][ C1] ? tomoyo_file_ioctl+0x23/0x30 [ 70.663906][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 70.670129][ C1] ? security_file_ioctl+0x8d/0xc0 [ 70.675224][ C1] ksys_ioctl+0xab/0xd0 [ 70.679360][ C1] __x64_sys_ioctl+0x73/0xb0 [ 70.683934][ C1] do_syscall_64+0xfa/0x760 [ 70.688430][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.694296][ C1] RIP: 0033:0x443e29 [ 70.698172][ C1] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 70.717751][ C1] RSP: 002b:00007fff60217db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 70.726150][ C1] RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443e29 [ 70.734106][ C1] RDX: 0000000020000100 RSI: 00000000c018643a RDI: 0000000000000003 [ 70.742054][ C1] RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0 [ 70.750001][ C1] R10: 000000000000000f R11: 0000000000000246 R12: 0000000000401b30 [ 70.757952][ C1] R13: 0000000000401bc0 R14: 0000000000000000 R15: 0000000000000000 [ 70.767307][ C1] Kernel Offset: disabled [ 70.771705][ C1] Rebooting in 86400 seconds..