[....] 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. [ 85.282363][ T27] kauditd_printk_skb: 4 callbacks suppressed [ 85.282373][ T27] audit: type=1800 audit(1584239646.413:29): pid=9781 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 [ 85.329860][ T27] audit: type=1800 audit(1584239646.413:30): pid=9781 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 '10.128.1.56' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 95.058054][ T9935] [ 95.060889][ T9935] ===================================== [ 95.066526][ T9935] WARNING: bad unlock balance detected! [ 95.072679][ T9935] 5.6.0-rc3-next-20200228-syzkaller #0 Not tainted [ 95.079343][ T9935] ------------------------------------- [ 95.084874][ T9935] syz-executor166/9935 is trying to release lock (&ovl_i_lock_key[depth]) at: [ 95.093735][ T9935] [] ovl_llseek+0x250/0x350 [ 95.099804][ T9935] but there are no more locks to release! [ 95.105507][ T9935] [ 95.105507][ T9935] other info that might help us debug this: [ 95.114534][ T9935] 1 lock held by syz-executor166/9935: [ 95.120437][ T9935] #0: ffff88809a5221a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 [ 95.129028][ T9935] [ 95.129028][ T9935] stack backtrace: [ 95.135745][ T9935] CPU: 1 PID: 9935 Comm: syz-executor166 Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 [ 95.145756][ T9935] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 95.156098][ T9935] Call Trace: [ 95.159388][ T9935] dump_stack+0x188/0x20d [ 95.163703][ T9935] ? ovl_llseek+0x250/0x350 [ 95.168215][ T9935] lock_release+0x586/0x7c0 [ 95.172718][ T9935] ? lock_downgrade+0x7f0/0x7f0 [ 95.177751][ T9935] ? lock_acquire+0x197/0x420 [ 95.182520][ T9935] ? ext4_llseek+0x1fc/0x2e0 [ 95.187140][ T9935] __mutex_unlock_slowpath+0x81/0x660 [ 95.192527][ T9935] ? wait_for_completion+0x3c0/0x3c0 [ 95.197821][ T9935] ? vfs_setpos+0xb8/0x140 [ 95.204202][ T9935] ovl_llseek+0x250/0x350 [ 95.208549][ T9935] ? ovl_aio_rw_complete+0x80/0x80 [ 95.213673][ T9935] ? ovl_aio_rw_complete+0x80/0x80 [ 95.218782][ T9935] ksys_lseek+0x10b/0x1a0 [ 95.223113][ T9935] do_syscall_64+0xf6/0x790 [ 95.227626][ T9935] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 95.233687][ T9935] RIP: 0033:0x4459b9 [ 95.237565][ T9935] Code: e8 bc b7 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 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 95.257458][ T9