[....] 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. [ 29.270942] kauditd_printk_skb: 7 callbacks suppressed [ 29.270954] audit: type=1800 audit(1543613339.843:29): pid=5864 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 [ 29.298076] audit: type=1800 audit(1543613339.843:30): pid=5864 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 syzkaller login: [ 33.768278] sshd (6003) used greatest stack depth: 15744 bytes left Warning: Permanently added '10.128.10.47' (ECDSA) to the list of known hosts. executing program [ 40.266820] [ 40.268489] ==================================== [ 40.273479] WARNING: syz-executor533/6020 still has locks held! [ 40.279548] 4.20.0-rc4+ #356 Not tainted [ 40.283859] ------------------------------------ [ 40.288637] 1 lock held by syz-executor533/6020: [ 40.293421] #0: 00000000798b7d90 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds+0x53/0x120 [ 40.302665] [ 40.302665] stack backtrace: [ 40.307256] CPU: 1 PID: 6020 Comm: syz-executor533 Not tainted 4.20.0-rc4+ #356 [ 40.314701] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.324044] Call Trace: [ 40.326626] dump_stack+0x244/0x39d [ 40.330257] ? dump_stack_print_info.cold.1+0x20/0x20 [ 40.335445] ? vprintk_func+0x85/0x181 [ 40.339330] debug_check_no_locks_held.cold.49+0x93/0x9f [ 40.344775] flush_old_exec+0x1ea2/0x2480 [ 40.348918] ? save_stack+0x43/0xd0 [ 40.352540] ? __kmalloc+0x15b/0x760 [ 40.356250] ? copy_strings_kernel+0x110/0x110 [ 40.360823] ? iov_iter_init+0xe5/0x210 [ 40.364792] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 40.370321] ? __vfs_read+0x11f/0x9b0 [ 40.374114] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.379665] ? fsnotify+0x50e/0xef0 [ 40.383286] ? fsnotify+0xef0/0xef0 [ 40.386905] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.392440] ? fsnotify_first_mark+0x350/0x350 [ 40.397015] ? __fsnotify_parent+0xcc/0x430 [ 40.401328] ? fsnotify+0xef0/0xef0 [ 40.404951] ? rw_verify_area+0x118/0x360 [ 40.409089] ? vfs_read+0x1ce/0x3c0 [ 40.412710] ? kernel_read+0xab/0x120 [ 40.416499] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 40.421506] ? load_elf_phdrs+0x1cd/0x260 [ 40.425643] ? writenote+0x3d0/0x3d0 [ 40.429361] ? refcount_inc_not_zero_checked+0x2f0/0x2f0 [ 40.434814] load_elf_binary+0xa39/0x5620 [ 40.438952] ? find_held_lock+0x36/0x1c0 [ 40.443009] ? notesize.isra.6+0x80/0x80 [ 40.447062] ? ima_file_mmap+0x160/0x160 [ 40.451114] ? lock_downgrade+0x900/0x900 [ 40.455281] ? kasan_check_write+0x14/0x20 [ 40.459510] search_binary_handler+0x17d/0x570 [ 40.464088] __do_execve_file.isra.33+0x1661/0x25d0 [ 40.469167] ? prepare_bprm_creds+0x120/0x120 [ 40.473666] ? usercopy_warn+0x110/0x110 [ 40.477729] ? kmem_cache_alloc+0x58f/0x730 [ 40.482046] ? check_preemption_disabled+0x48/0x280 [ 40.487107] ? rcu_lockdep_current_cpu_online+0x1a4/0x210 [ 40.492641] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 40.498190] ? strncpy_from_user+0x411/0x5a0 [ 40.502596] ? digsig_verify+0x1530/0x1530 [ 40.506848] ? kmem_cache_alloc+0x33a/0x730 [ 40.511182] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.516713] __x64_sys_execveat+0xed/0x130 [ 40.520945] do_syscall_64+0x1b9/0x820 [ 40.524825] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 40.530192] ? syscall_return_slowpath+0x5e0/0x5e0 [ 40.535115] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.539971] ? trace_hardirqs_on_caller+0x310/0x310 [ 40.544984] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 40.549991] ? prepare_exit_to_usermode+0x291/0x3b0 [ 40.555002] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.559838] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.565017] RIP: 0033:0x4456c9 [ 40.568203] Code: e8 6c b6 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 [ 40.587095] RSP: 002b:00007f38ac3a5db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000142 [ 40.594908] RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 00000000004456c9 [ 40.602185] RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 [ 40.609447] RBP: 00000000006dac20 R08: 0000000000001000 R09: 0000000000000000 [ 40.616708] R10: