[....] 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. [ 28.889012] kauditd_printk_skb: 7 callbacks suppressed [ 28.889024] audit: type=1800 audit(1543652964.513:29): pid=5871 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 [ 28.918227] audit: type=1800 audit(1543652964.513:30): pid=5871 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 '10.128.10.61' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program syzkaller login: [ 109.840615] ------------[ cut here ]------------ [ 109.845387] DEBUG_LOCKS_WARN_ON(depth <= 0) [ 109.845456] WARNING: CPU: 0 PID: 6044 at kernel/locking/lockdep.c:3595 lock_release+0x740/0xa10 [ 109.858557] Kernel panic - not syncing: panic_on_warn set ... [ 109.864437] CPU: 0 PID: 6044 Comm: syz-executor719 Not tainted 4.20.0-rc1-next-20181109+ #110 [ 109.873117] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 109.882459] Call Trace: [ 109.885027] dump_stack+0x244/0x39d [ 109.888646] ? dump_stack_print_info.cold.1+0x20/0x20 [ 109.893817] panic+0x2ad/0x55c [ 109.896988] ? add_taint.cold.5+0x16/0x16 [ 109.901115] ? __warn.cold.8+0x5/0x45 [ 109.904893] ? __warn+0xe8/0x1d0 [ 109.908298] ? lock_release+0x740/0xa10 [ 109.912258] __warn.cold.8+0x20/0x45 [ 109.915953] ? lock_release+0x740/0xa10 [ 109.919905] report_bug+0x254/0x2d0 [ 109.923512] do_error_trap+0x11b/0x200 [ 109.927376] do_invalid_op+0x36/0x40 [ 109.931068] ? lock_release+0x740/0xa10 [ 109.935021] invalid_op+0x14/0x20 [ 109.938456] RIP: 0010:lock_release+0x740/0xa10 [ 109.943019] 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 [ 109.961902] RSP: 0018:ffff8801c0ebf868 EFLAGS: 00010086 [ 109.967249] RAX: 0000000000000000 RBX: 1ffff100381d7f12 RCX: 0000000000000000 [ 109.974502] RDX: 0000000000000000 RSI: ffffffff8165ba15 RDI: 0000000000000006 [ 109.981751] RBP: ffff8801c0ebf998 R08: ffff8801c0e5a4c0 R09: fffffbfff12b2254 [ 109.988997] R10: fffffbfff12b2254 R11: ffffffff895912a3 R12: ffffffff8b0e27a0 [ 109.996283] R13: ffff8801c0ebf970 R14: ffff8801c0e5a4c0 R15: ffff8801c0ebf8b0 [ 110.003547] ? vprintk_func+0x85/0x181 [ 110.007416] ? lock_release+0x740/0xa10 [ 110.011475] ? loop_control_ioctl+0xf5/0x4e0 [ 110.015928] ? lock_downgrade+0x900/0x900 [ 110.020063] ? __radix_tree_lookup+0x3a7/0x500 [ 110.024625] ? radix_tree_insert+0x870/0x870 [ 110.029014] ? find_held_lock+0x36/0x1c0 [ 110.033057] __mutex_unlock_slowpath+0x102/0x8c0 [ 110.037791] ? __fget+0x4aa/0x740 [ 110.041223] ? wait_for_completion+0x8a0/0x8a0 [ 110.045837] ? check_preemption_disabled+0x48/0x280 [ 110.050843] ? radix_tree_lookup+0x21/0x30 [ 110.055057] ? idr_find+0x44/0x50 [ 110.058492] ? loop_lookup+0x105/0x230 [ 110.062358] ? loop_exit_cb+0x20/0x20 [ 110.066138] mutex_unlock+0xd/0x10 [ 110.069658] loop_control_ioctl+0xf5/0x4e0 [ 110.073869] ? loop_add+0xa20/0xa20 [ 110.077478] ? trace_hardirqs_off+0xb8/0x310 [ 110.081874] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 110.087391] ? loop_add+0xa20/0xa20 [ 110.090998] do_vfs_ioctl+0x1de/0x1790 [ 110.094873] ? rcu_lockdep_current_cpu_online+0x1a4/0x210 [ 110.100392] ? ioctl_preallocate+0x300/0x300 [ 110.104788] ? __fget_light+0x2e9/0x430 [ 110.108746] ? fget_raw+0x20/0x20 [ 110.112179] ? putname+0xf2/0x130 [ 110.115611] ? rcu_read_lock_sched_held+0x14f/0x180 [ 110.120605] ? kmem_cache_free+0x24f/0x290 [ 110.124824] ? __x64_sys_futex+0x47f/0x6a0 [ 110.129040] ? do_syscall_64+0x9a/0x820 [ 110.132999] ? do_syscall_64+0x9a/0x820 [ 110.136956] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 110.142449] ? security_file_ioctl+0x94/0xc0 [ 110.146843] ksys_ioctl+0xa9/0xd0 [ 110.150276] __x64_sys_ioctl+0x73/0xb0 [ 110.154146] do_syscall_64+0x1b9/0x820 [ 110.158014] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 110.163354] ? syscall_return_slowpath+0x5e0/0x5e0 [ 110.168337] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 110.173165] ? trace_hardirqs_on_caller+0x310/0x310 [ 110.178172] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 110.183166] ? prepare_exit_to_usermode+0x291/0x3b0 [ 110.188160] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 110.192985] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 110.198151] RIP: 0033:0x446719 [ 110.201323] Code: e8 bc b9 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 fb 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 110.220206] RSP: 002b:00007fbcc62b1da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 110.227892] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446719 [ 110.235140] RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 [ 110.242386] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 110.249634] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 110.256890] R13: 6f72746e6f632d70 R14: 6f6f6c2f7665642f R15: 00000000006dbd2c [ 110.265002] Kernel Offset: disabled [ 110.268622] Rebooting in 86400 seconds..