[....] 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. [ 29.496318] kauditd_printk_skb: 8 callbacks suppressed [ 29.496329] audit: type=1800 audit(1542140225.145:29): pid=5889 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 [ 29.524487] audit: type=1800 audit(1542140225.145:30): pid=5889 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 '10.128.0.77' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 65.064243] ------------[ cut here ]------------ [ 65.069088] DEBUG_LOCKS_WARN_ON(depth <= 0) [ 65.069171] WARNING: CPU: 0 PID: 6054 at kernel/locking/lockdep.c:3595 lock_release+0x740/0xa10 [ 65.082301] Kernel panic - not syncing: panic_on_warn set ... [ 65.088224] CPU: 0 PID: 6054 Comm: syz-executor329 Not tainted 4.20.0-rc1-next-20181109+ #110 [ 65.096944] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.106363] Call Trace: [ 65.108947] dump_stack+0x244/0x39d [ 65.112563] ? dump_stack_print_info.cold.1+0x20/0x20 [ 65.117749] panic+0x2ad/0x55c [ 65.121057] ? add_taint.cold.5+0x16/0x16 [ 65.125192] ? __warn.cold.8+0x5/0x45 [ 65.128976] ? __warn+0xe8/0x1d0 [ 65.132328] ? lock_release+0x740/0xa10 [ 65.136287] __warn.cold.8+0x20/0x45 [ 65.140099] ? lock_release+0x740/0xa10 [ 65.144062] report_bug+0x254/0x2d0 [ 65.147728] do_error_trap+0x11b/0x200 [ 65.151609] do_invalid_op+0x36/0x40 [ 65.155306] ? lock_release+0x740/0xa10 [ 65.159278] invalid_op+0x14/0x20 [ 65.162717] RIP: 0010:lock_release+0x740/0xa10 [ 65.167290] 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 [ 65.186283] RSP: 0018:ffff8801d836f868 EFLAGS: 00010086 [ 65.191741] RAX: 0000000000000000 RBX: 1ffff1003b06df12 RCX: 0000000000000000 [ 65.199104] RDX: 0000000000000000 RSI: ffffffff8165ba15 RDI: 0000000000000006 [ 65.206368] RBP: ffff8801d836f998 R08: ffff8801bebfe400 R09: fffffbfff12b2254 [ 65.213626] R10: fffffbfff12b2254 R11: ffffffff895912a3 R12: ffffffff8b0e27a0 [ 65.220935] R13: ffff8801d836f970 R14: ffff8801bebfe400 R15: ffff8801d836f8b0 [ 65.228212] ? vprintk_func+0x85/0x181 [ 65.232088] ? lock_release+0x740/0xa10 [ 65.236150] ? loop_control_ioctl+0xf5/0x4e0 [ 65.240554] ? lock_downgrade+0x900/0x900 [ 65.244687] ? __radix_tree_lookup+0x3a7/0x500 [ 65.249259] ? radix_tree_insert+0x870/0x870 [ 65.253663] ? find_held_lock+0x36/0x1c0 [ 65.257713] __mutex_unlock_slowpath+0x102/0x8c0 [ 65.262452] ? __fget+0x4aa/0x740 [ 65.265887] ? wait_for_completion+0x8a0/0x8a0 [ 65.270462] ? check_preemption_disabled+0x48/0x280 [ 65.275465] ? radix_tree_lookup+0x21/0x30 [ 65.279682] ? idr_find+0x44/0x50 [ 65.283124] ? loop_lookup+0x105/0x230 [ 65.286998] ? loop_exit_cb+0x20/0x20 [ 65.290783] mutex_unlock+0xd/0x10 [ 65.294318] loop_control_ioctl+0xf5/0x4e0 [ 65.298587] ? loop_add+0xa20/0xa20 [ 65.302213] ? trace_hardirqs_off+0xb8/0x310 [ 65.306608] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 65.312133] ? loop_add+0xa20/0xa20 [ 65.315773] do_vfs_ioctl+0x1de/0x1790 [ 65.319654] ? rcu_lockdep_current_cpu_online+0x1a4/0x210 [ 65.325184] ? ioctl_preallocate+0x300/0x300 [ 65.329578] ? __fget_light+0x2e9/0x430 [ 65.333535] ? fget_raw+0x20/0x20 [ 65.336964] ? putname+0xf2/0x130 [ 65.340403] ? rcu_read_lock_sched_held+0x14f/0x180 [ 65.345407] ? kmem_cache_free+0x24f/0x290 [ 65.349630] ? __x64_sys_futex+0x47f/0x6a0 [ 65.353851] ? do_syscall_64+0x9a/0x820 [ 65.357805] ? do_syscall_64+0x9a/0x820 [ 65.361766] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 65.366339] ? security_file_ioctl+0x94/0xc0 [ 65.370726] ksys_ioctl+0xa9/0xd0 [ 65.374160] __x64_sys_ioctl+0x73/0xb0 [ 65.378028] do_syscall_64+0x1b9/0x820 [ 65.381897] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 65.387307] ? syscall_return_slowpath+0x5e0/0x5e0 [ 65.392225] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 65.397050] ? trace_hardirqs_on_caller+0x310/0x310 [ 65.402093] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 65.407096] ? prepare_exit_to_usermode+0x291/0x3b0 [ 65.412096] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 65.416921] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 65.422093] RIP: 0033:0x446239 [ 65.425277] 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 [ 65.444166] RSP: 002b:00007f60433dfda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 65.451860] RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000446239 [ 65.459178] RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 [ 65.466434] RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 [ 65.473688] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac2c [ 65.480944] R13: 6f72746e6f632d70 R14: 6f6f6c2f7665642f R15: 00000000006dad2c [ 65.489029] Kernel Offset: disabled [ 65.492648] Rebooting in 86400 seconds..