[....] 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. [ 28.441127] kauditd_printk_skb: 7 callbacks suppressed [ 28.441139] audit: type=1800 audit(1544125440.279:29): pid=5832 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 [ 28.466278] audit: type=1800 audit(1544125440.279:30): pid=5832 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 '10.128.15.223' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 48.629320] ------------[ cut here ]------------ [ 48.634236] DEBUG_LOCKS_WARN_ON(depth <= 0) [ 48.634306] WARNING: CPU: 1 PID: 6394 at kernel/locking/lockdep.c:3595 lock_release+0x740/0xa10 [ 48.647409] Kernel panic - not syncing: panic_on_warn set ... [ 48.653276] CPU: 1 PID: 6394 Comm: syz-executor828 Not tainted 4.20.0-rc1-next-20181109+ #110 [ 48.661914] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.671355] Call Trace: [ 48.673928] dump_stack+0x244/0x39d [ 48.677538] ? dump_stack_print_info.cold.1+0x20/0x20 [ 48.682738] panic+0x2ad/0x55c [ 48.685911] ? add_taint.cold.5+0x16/0x16 [ 48.690039] ? __warn.cold.8+0x5/0x45 [ 48.693816] ? __warn+0xe8/0x1d0 [ 48.697162] ? lock_release+0x740/0xa10 [ 48.701116] __warn.cold.8+0x20/0x45 [ 48.704808] ? lock_release+0x740/0xa10 [ 48.708779] report_bug+0x254/0x2d0 [ 48.712383] do_error_trap+0x11b/0x200 [ 48.716246] do_invalid_op+0x36/0x40 [ 48.719937] ? lock_release+0x740/0xa10 [ 48.723890] invalid_op+0x14/0x20 [ 48.727323] RIP: 0010:lock_release+0x740/0xa10 [ 48.731883] 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 [ 48.750762] RSP: 0018:ffff8801bb807868 EFLAGS: 00010086 [ 48.756102] RAX: 0000000000000000 RBX: 1ffff10037700f12 RCX: 0000000000000000 [ 48.763349] RDX: 0000000000000000 RSI: ffffffff8165ba15 RDI: 0000000000000006 [ 48.770598] RBP: ffff8801bb807998 R08: ffff8801ba208700 R09: fffffbfff12b2254 [ 48.777846] R10: fffffbfff12b2254 R11: ffffffff895912a3 R12: ffffffff8b0e27a0 [ 48.785198] R13: ffff8801bb807970 R14: ffff8801ba208700 R15: ffff8801bb8078b0 [ 48.792463] ? vprintk_func+0x85/0x181 [ 48.796334] ? lock_release+0x740/0xa10 [ 48.800289] ? loop_control_ioctl+0xf5/0x4e0 [ 48.804679] ? lock_downgrade+0x900/0x900 [ 48.808807] ? __radix_tree_lookup+0x3a7/0x500 [ 48.813367] ? radix_tree_insert+0x870/0x870 [ 48.817773] ? find_held_lock+0x36/0x1c0 [ 48.821833] __mutex_unlock_slowpath+0x102/0x8c0 [ 48.826570] ? __fget+0x4aa/0x740 [ 48.830001] ? wait_for_completion+0x8a0/0x8a0 [ 48.834562] ? check_preemption_disabled+0x48/0x280 [ 48.839555] ? radix_tree_lookup+0x21/0x30 [ 48.843772] ? idr_find+0x44/0x50 [ 48.847206] ? loop_lookup+0x105/0x230 [ 48.851070] ? loop_exit_cb+0x20/0x20 [ 48.854851] mutex_unlock+0xd/0x10 [ 48.858373] loop_control_ioctl+0xf5/0x4e0 [ 48.862585] ? loop_add+0xa20/0xa20 [ 48.866190] ? trace_hardirqs_off+0xb8/0x310 [ 48.870593] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 48.876107] ? loop_add+0xa20/0xa20 [ 48.879715] do_vfs_ioctl+0x1de/0x1790 [ 48.883598] ? rcu_lockdep_current_cpu_online+0x1a4/0x210 [ 48.889120] ? ioctl_preallocate+0x300/0x300 [ 48.893508] ? __fget_light+0x2e9/0x430 [ 48.897460] ? fget_raw+0x20/0x20 [ 48.900895] ? putname+0xf2/0x130 [ 48.904354] ? rcu_read_lock_sched_held+0x14f/0x180 [ 48.909352] ? kmem_cache_free+0x24f/0x290 [ 48.913568] ? __x64_sys_futex+0x47f/0x6a0 [ 48.917783] ? do_syscall_64+0x9a/0x820 [ 48.921754] ? do_syscall_64+0x9a/0x820 [ 48.925734] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 48.930312] ? security_file_ioctl+0x94/0xc0 [ 48.934699] ksys_ioctl+0xa9/0xd0 [ 48.938136] __x64_sys_ioctl+0x73/0xb0 [ 48.942001] do_syscall_64+0x1b9/0x820 [ 48.945902] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 48.951251] ? syscall_return_slowpath+0x5e0/0x5e0 [ 48.956157] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.960977] ? trace_hardirqs_on_caller+0x310/0x310 [ 48.965971] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 48.970967] ? prepare_exit_to_usermode+0x291/0x3b0 [ 48.975965] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.980790] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.985958] RIP: 0033:0x446369 [ 48.989129] Code: e8 1c b4 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 [ 49.008013] RSP: 002b:00007f39ea554ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 49.015700] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446369 [ 49.022955] RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 [ 49.030205] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 49.037456] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 49.044729] R13: 00007ffce5cb1cdf R14: 00007f39ea5559c0 R15: 00000000006dbd2c [ 49.052875] Kernel Offset: disabled [ 49.056504] Rebooting in 86400 seconds..