[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 67.857549][ T27] audit: type=1800 audit(1576667059.447:25): pid=9251 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 67.879229][ T27] audit: type=1800 audit(1576667059.447:26): pid=9251 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 67.938319][ T27] audit: type=1800 audit(1576667059.447:27): pid=9251 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 '10.128.0.251' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 78.257059][ T9404] ------------[ cut here ]------------ [ 78.262556][ T9404] WARNING: CPU: 1 PID: 9404 at drivers/gpu/drm/vkms/vkms_gem.c:37 vkms_gem_free_object+0x92/0xb0 [ 78.273046][ T9404] Kernel panic - not syncing: panic_on_warn set ... [ 78.279618][ T9404] CPU: 1 PID: 9404 Comm: syz-executor903 Not tainted 5.5.0-rc2-next-20191218-syzkaller #0 [ 78.289500][ T9404] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 78.299552][ T9404] Call Trace: [ 78.302849][ T9404] dump_stack+0x197/0x210 [ 78.307165][ T9404] ? __vkms_gem_create+0xb0/0x100 [ 78.312187][ T9404] panic+0x2e3/0x75c [ 78.317158][ T9404] ? add_taint.cold+0x16/0x16 [ 78.321840][ T9404] ? printk+0xba/0xed [ 78.325812][ T9404] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 78.331275][ T9404] ? __warn.cold+0x14/0x3e [ 78.335685][ T9404] ? __warn+0xd9/0x1cf [ 78.339741][ T9404] ? vkms_gem_free_object+0x92/0xb0 [ 78.344919][ T9404] __warn.cold+0x2f/0x3e [ 78.349141][ T9404] ? report_bug.cold+0x63/0xb2 [ 78.353884][ T9404] ? vkms_gem_free_object+0x92/0xb0 [ 78.359080][ T9404] report_bug+0x289/0x300 [ 78.363395][ T9404] do_error_trap+0x11b/0x200 [ 78.367981][ T9404] do_invalid_op+0x37/0x50 [ 78.372377][ T9404] ? vkms_gem_free_object+0x92/0xb0 [ 78.377574][ T9404] invalid_op+0x23/0x30 [ 78.381713][ T9404] RIP: 0010:vkms_gem_free_object+0x92/0xb0 [ 78.387511][ T9404] Code: a4 08 24 fd 49 8d bc 24 00 02 00 00 e8 d7 c6 08 fd 4c 89 e7 e8 5f 0d aa ff 4c 89 e7 e8 27 a3 61 fd 41 5c 5d c3 e8 7e 08 24 fd <0f> 0b eb a2 e8 75 08 24 fd 0f 0b eb c8 e8 7c f2 61 fd eb b6 e8 75 [ 78.407109][ T9404] RSP: 0018:ffffc90001f979f0 EFLAGS: 00010293 [ 78.413159][ T9404] RAX: ffff8880a6468440 RBX: ffffffff8a00c540 RCX: ffffffff83fb6567 [ 78.421112][ T9404] RDX: 0000000000000000 RSI: ffffffff845144e2 RDI: ffff8880a0121280 [ 78.429084][ T9404] RBP: ffffc90001f979f8 R08: ffff8880a6468440 R09: ffffed1014024201 [ 78.437036][ T9404] R10: ffffed1014024200 R11: ffff8880a0121003 R12: ffff8880a0121000 [ 78.445012][ T9404] R13: ffff8880a271c000 R14: ffffffff84514450 R15: ffff8880a271c020 [ 78.452977][ T9404] ? __vkms_gem_create+0x100/0x100 [ 78.458074][ T9404] ? drm_gem_object_put_unlocked+0x127/0x1c0 [ 78.464047][ T9404] ? vkms_gem_free_object+0x92/0xb0 [ 78.469231][ T9404] drm_gem_object_free+0x100/0x220 [ 78.474336][ T9404] drm_gem_object_put_unlocked+0x196/0x1c0 [ 78.480125][ T9404] drm_gem_object_handle_put_unlocked+0x1ad/0x2d0 [ 78.486618][ T9404] drm_gem_object_release_handle+0x102/0x1c0 [ 78.492629][ T9404] idr_for_each+0x138/0x250 [ 78.497157][ T9404] ? drm_gem_object_handle_put_unlocked+0x2d0/0x2d0 [ 78.503770][ T9404] ? idr_find+0x60/0x60 [ 78.507908][ T9404] ? drm_file_free.part.0+0x5c9/0xc00 [ 78.513267][ T9404] drm_gem_release+0x27/0x40 [ 78.517838][ T9404] drm_file_free.part.0+0x7f4/0xc00 [ 78.523032][ T9404] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 78.529257][ T9404] drm_release+0x286/0x3f0 [ 78.533754][ T9404] ? ima_file_free+0xc9/0x430 [ 78.540089][ T9404] __fput+0x2ff/0x890 [ 78.544061][ T9404] ? drm_lastclose+0xa0/0xa0 [ 78.548671][ T9404] ____fput+0x16/0x20 [ 78.552640][ T9404] task_work_run+0x145/0x1c0 [ 78.557253][ T9404] do_exit+0x909/0x2f20 [ 78.561418][ T9404] ? find_held_lock+0x35/0x130 [ 78.566175][ T9404] ? __fd_install+0x1bc/0x640 [ 78.570837][ T9404] ? mm_update_next_owner+0x7c0/0x7c0 [ 78.576202][ T9404] ? lock_downgrade+0x920/0x920 [ 78.581038][ T9404] ? tomoyo_file_ioctl+0x23/0x30 [ 78.585968][ T9404] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 78.592203][ T9404] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 78.597654][ T9404] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 78.603098][ T9404] do_group_exit+0x135/0x360 [ 78.607686][ T9404] __x64_sys_exit_group+0x44/0x50 [ 78.612693][ T9404] do_syscall_64+0xfa/0x790 [ 78.617189][ T9404] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 78.623063][ T9404] RIP: 0033:0x442bb8 [ 78.626945][ T9404] Code: Bad RIP value. [ 78.631001][ T9404] RSP: 002b:00007ffc6a0e9a68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 78.639395][ T9404] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442bb8 [ 78.647360][ T9404] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 78.655328][ T9404] RBP: 00000000004c24c8 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 78.663296][ T9404] R10: 00000000004002e0 R11: 0000000000000246 R12: 0000000000000001 [ 78.671251][ T9404] R13: 00000000006d41a0 R14: 0000000000000000 R15: 0000000000000000 [ 78.680678][ T9404] Kernel Offset: disabled [ 78.685087][ T9404] Rebooting in 86400 seconds..