[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 61.457910][ T26] audit: type=1800 audit(1570855723.799:25): pid=8888 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 61.503159][ T26] audit: type=1800 audit(1570855723.799:26): pid=8888 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 61.546322][ T26] audit: type=1800 audit(1570855723.809:27): pid=8888 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 '10.128.0.183' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 71.619409][ T9040] ------------[ cut here ]------------ [ 71.625058][ T9040] WARNING: CPU: 1 PID: 9040 at drivers/gpu/drm/vkms/vkms_gem.c:37 vkms_gem_free_object+0x92/0xb0 [ 71.635536][ T9040] Kernel panic - not syncing: panic_on_warn set ... [ 71.643384][ T9040] CPU: 1 PID: 9040 Comm: syz-executor028 Not tainted 5.4.0-rc2-next-20191011 #0 [ 71.652388][ T9040] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.662435][ T9040] Call Trace: [ 71.665776][ T9040] dump_stack+0x172/0x1f0 [ 71.670149][ T9040] ? vkms_gem_free_object+0x90/0xb0 [ 71.675501][ T9040] panic+0x2e3/0x75c [ 71.679395][ T9040] ? add_taint.cold+0x16/0x16 [ 71.684099][ T9040] ? printk+0xba/0xed [ 71.688081][ T9040] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 71.693698][ T9040] ? __warn.cold+0x14/0x35 [ 71.698116][ T9040] ? __warn+0xd9/0x1d0 [ 71.702260][ T9040] ? vkms_gem_free_object+0x92/0xb0 [ 71.707438][ T9040] __warn.cold+0x2f/0x35 [ 71.711672][ T9040] ? report_bug.cold+0x63/0xb2 [ 71.716436][ T9040] ? vkms_gem_free_object+0x92/0xb0 [ 71.721651][ T9040] report_bug+0x289/0x300 [ 71.725971][ T9040] do_error_trap+0x11b/0x200 [ 71.730713][ T9040] do_invalid_op+0x37/0x50 [ 71.735122][ T9040] ? vkms_gem_free_object+0x92/0xb0 [ 71.740303][ T9040] invalid_op+0x23/0x30 [ 71.744470][ T9040] RIP: 0010:vkms_gem_free_object+0x92/0xb0 [ 71.750277][ T9040] Code: 44 68 7f fd 49 8d bc 24 f8 01 00 00 e8 c7 8d 64 fd 4c 89 e7 e8 3f 39 ae ff 4c 89 e7 e8 f7 9a ba fd 41 5c 5d c3 e8 1e 68 7f fd <0f> 0b eb a2 e8 15 68 7f fd 0f 0b eb c8 e8 2c e7 ba fd eb b6 e8 25 [ 71.770479][ T9040] RSP: 0018:ffff8880971df9e8 EFLAGS: 00010293 [ 71.776532][ T9040] RAX: ffff8880989c2200 RBX: ffffffff894e5000 RCX: ffffffff83a1eda6 [ 71.784541][ T9040] RDX: 0000000000000000 RSI: ffffffff83f3ab02 RDI: ffff8880a8c4fa78 [ 71.792632][ T9040] RBP: ffff8880971df9f0 R08: ffff8880989c2200 R09: ffffed1012e3bf36 [ 71.800603][ T9040] R10: ffffed1012e3bf35 R11: 0000000000000003 R12: ffff8880a8c4f800 [ 71.808561][ T9040] R13: ffff8880a3ab8000 R14: ffffffff83f3aa70 R15: ffff8880a3ab8020 [ 71.816532][ T9040] ? __vkms_gem_create+0x100/0x100 [ 71.821658][ T9040] ? drm_gem_object_put_unlocked+0x116/0x170 [ 71.827649][ T9040] ? vkms_gem_free_object+0x92/0xb0 [ 71.832840][ T9040] ? vkms_gem_free_object+0x92/0xb0 [ 71.838142][ T9040] drm_gem_object_free+0x100/0x220 [ 71.843245][ T9040] drm_gem_object_put_unlocked+0x127/0x170 [ 71.849149][ T9040] drm_gem_object_handle_put_unlocked+0x1ad/0x2d0 [ 71.855710][ T9040] drm_gem_object_release_handle+0x102/0x1c0 [ 71.861693][ T9040] idr_for_each+0x138/0x250 [ 71.866402][ T9040] ? drm_gem_object_handle_put_unlocked+0x2d0/0x2d0 [ 71.873096][ T9040] ? idr_find+0x60/0x60 [ 71.877247][ T9040] ? drm_file_free.part.0+0x5c9/0xc00 [ 71.883024][ T9040] drm_gem_release+0x27/0x40 [ 71.887608][ T9040] drm_file_free.part.0+0x7f4/0xc00 [ 71.892800][ T9040] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 71.899059][ T9040] drm_release+0x286/0x3f0 [ 71.903467][ T9040] ? ima_file_free+0xc9/0x430 [ 71.908132][ T9040] __fput+0x2ff/0x890 [ 71.912532][ T9040] ? drm_lastclose+0xa0/0xa0 [ 71.917110][ T9040] ____fput+0x16/0x20 [ 71.921213][ T9040] task_work_run+0x145/0x1c0 [ 71.925881][ T9040] do_exit+0x904/0x2e60 [ 71.930025][ T9040] ? mm_update_next_owner+0x640/0x640 [ 71.935407][ T9040] ? tomoyo_file_ioctl+0x23/0x30 [ 71.940336][ T9040] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 71.946579][ T9040] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 71.952271][ T9040] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 71.957735][ T9040] do_group_exit+0x135/0x360 [ 71.962353][ T9040] __x64_sys_exit_group+0x44/0x50 [ 71.967382][ T9040] do_syscall_64+0xfa/0x760 [ 71.971899][ T9040] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.977887][ T9040] RIP: 0033:0x442bb8 [ 71.981781][ T9040] Code: Bad RIP value. [ 71.985928][ T9040] RSP: 002b:00007ffd8fdc0b98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 71.994502][ T9040] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442bb8 [ 72.002629][ T9040] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 72.010600][ T9040] RBP: 00000000004c24c8 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 72.018575][ T9040] R10: 00000000004002e0 R11: 0000000000000246 R12: 0000000000000001 [ 72.026782][ T9040] R13: 00000000006d41a0 R14: 0000000000000000 R15: 0000000000000000 [ 72.037313][ T9040] Kernel Offset: disabled [ 72.041845][ T9040] Rebooting in 86400 seconds..