[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 28.665632] kauditd_printk_skb: 7 callbacks suppressed [ 28.665644] audit: type=1800 audit(1543863711.607:29): pid=5856 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 28.692815] audit: type=1800 audit(1543863711.607:30): pid=5856 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.110' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 43.742069] ------------[ cut here ]------------ [ 43.746891] DEBUG_LOCKS_WARN_ON(depth <= 0) [ 43.746997] WARNING: CPU: 1 PID: 6030 at kernel/locking/lockdep.c:3595 lock_release+0x740/0xa10 [ 43.760152] Kernel panic - not syncing: panic_on_warn set ... [ 43.766038] CPU: 1 PID: 6030 Comm: syz-executor325 Not tainted 4.20.0-rc1-next-20181109+ #110 [ 43.774819] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.784261] Call Trace: [ 43.786837] dump_stack+0x244/0x39d [ 43.790454] ? dump_stack_print_info.cold.1+0x20/0x20 [ 43.795636] panic+0x2ad/0x55c [ 43.798824] ? add_taint.cold.5+0x16/0x16 [ 43.802956] ? __warn.cold.8+0x5/0x45 [ 43.806744] ? __warn+0xe8/0x1d0 [ 43.810097] ? lock_release+0x740/0xa10 [ 43.814062] __warn.cold.8+0x20/0x45 [ 43.817844] ? lock_release+0x740/0xa10 [ 43.821812] report_bug+0x254/0x2d0 [ 43.825426] do_error_trap+0x11b/0x200 [ 43.829301] do_invalid_op+0x36/0x40 [ 43.832999] ? lock_release+0x740/0xa10 [ 43.836961] invalid_op+0x14/0x20 [ 43.840411] RIP: 0010:lock_release+0x740/0xa10 [ 43.844985] Code: 03 38 d0 7c 08 84 d2 0f 85 da 02 00 00 8b 35 a7 95 b3 08 85 f6 75 15 48 c7 c6 20 66 2b 88 48 c7 c7 c0 33 2b 88 e8 10 36 e7 ff <0f> 0b 48 8b 95 e8 fe ff ff 4c 89 f7 48 8b b5 f0 fe ff ff e8 e8 58 [ 43.864054] RSP: 0018:ffff8801b8037868 EFLAGS: 00010086 [ 43.869476] RAX: 0000000000000000 RBX: 1ffff10037006f12 RCX: 0000000000000000 [ 43.876741] RDX: 0000000000000000 RSI: ffffffff8165ba15 RDI: 0000000000000006 [ 43.883994] RBP: ffff8801b8037998 R08: ffff8801c161c700 R09: fffffbfff12b2254 [ 43.891244] R10: fffffbfff12b2254 R11: ffffffff895912a3 R12: ffffffff8b0e27a0 [ 43.898496] R13: ffff8801b8037970 R14: ffff8801c161c700 R15: ffff8801b80378b0 [ 43.905763] ? vprintk_func+0x85/0x181 [ 43.909635] ? lock_release+0x740/0xa10 [ 43.913595] ? loop_control_ioctl+0xf5/0x4e0 [ 43.917998] ? lock_downgrade+0x900/0x900 [ 43.922132] ? __radix_tree_lookup+0x3a7/0x500 [ 43.926698] ? radix_tree_insert+0x870/0x870 [ 43.931099] ? find_held_lock+0x36/0x1c0 [ 43.935148] __mutex_unlock_slowpath+0x102/0x8c0 [ 43.939892] ? __fget+0x4aa/0x740 [ 43.943329] ? wait_for_completion+0x8a0/0x8a0 [ 43.947896] ? check_preemption_disabled+0x48/0x280 [ 43.952894] ? radix_tree_lookup+0x21/0x30 [ 43.957117] ? idr_find+0x44/0x50 [ 43.960554] ? loop_lookup+0x105/0x230 [ 43.964425] ? loop_exit_cb+0x20/0x20 [ 43.968208] mutex_unlock+0xd/0x10 [ 43.971736] loop_control_ioctl+0xf5/0x4e0 [ 43.975955] ? loop_add+0xa20/0xa20 [ 43.979571] ? trace_hardirqs_off+0xb8/0x310 [ 43.983969] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 43.989487] ? loop_add+0xa20/0xa20 [ 43.993234] do_vfs_ioctl+0x1de/0x1790 [ 43.997113] ? rcu_lockdep_current_cpu_online+0x1a4/0x210 [ 44.002633] ? ioctl_preallocate+0x300/0x300 [ 44.007027] ? __fget_light+0x2e9/0x430 [ 44.010985] ? fget_raw+0x20/0x20 [ 44.014421] ? putname+0xf2/0x130 [ 44.017857] ? rcu_read_lock_sched_held+0x14f/0x180 [ 44.022859] ? kmem_cache_free+0x24f/0x290 [ 44.027093] ? __x64_sys_futex+0x47f/0x6a0 [ 44.031311] ? do_syscall_64+0x9a/0x820 [ 44.035267] ? do_syscall_64+0x9a/0x820 [ 44.039227] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 44.043906] ? security_file_ioctl+0x94/0xc0 [ 44.048302] ksys_ioctl+0xa9/0xd0 [ 44.051742] __x64_sys_ioctl+0x73/0xb0 [ 44.055620] do_syscall_64+0x1b9/0x820 [ 44.059496] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 44.064904] ? syscall_return_slowpath+0x5e0/0x5e0 [ 44.069827] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.074654] ? trace_hardirqs_on_caller+0x310/0x310 [ 44.079656] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 44.084655] ? prepare_exit_to_usermode+0x291/0x3b0 [ 44.089654] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.094485] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.099664] RIP: 0033:0x446239 [ 44.102842] Code: e8 2c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 2b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 44.121737] RSP: 002b:00007fdad78c0da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 44.129429] RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000446239 [ 44.136680] RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 [ 44.143931] RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 [ 44.151185] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac2c [ 44.158437] R13: 6f72746e6f632d70 R14: 6f6f6c2f7665642f R15: 00000000006dad2c [ 44.166760] Kernel Offset: disabled [ 44.170382] Rebooting in 86400 seconds..