[   39.258296] audit: type=1800 audit(1572685881.119:31): pid=7445 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0
[   39.280482] audit: type=1800 audit(1572685881.119:32): pid=7445 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2450 res=0
Starting mcstransd: 
[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

Warning: Permanently added '10.128.0.44' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   47.480195] kauditd_printk_skb: 3 callbacks suppressed
[   47.480210] audit: type=1400 audit(1572685889.399:36): avc:  denied  { map } for  pid=7632 comm="syz-executor957" path="/root/syz-executor957245890" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
[   47.483453] 
[   47.513532] =============================
[   47.517659] WARNING: suspicious RCU usage
[   47.521791] 4.19.81 #0 Not tainted
[   47.525313] -----------------------------
[   47.529533] include/linux/radix-tree.h:241 suspicious rcu_dereference_check() usage!
[   47.537520] 
[   47.537520] other info that might help us debug this:
[   47.537520] 
[   47.546105] 
[   47.546105] rcu_scheduler_active = 2, debug_locks = 1
[   47.552859] 2 locks held by syz-executor957/7632:
[   47.557682]  #0: 0000000035a203a2 (&sb->s_type->i_mutex_key#12){+.+.}, at: memfd_fcntl+0x235/0x1750
[   47.566885]  #1: 000000006ab08fd8 (&(&(&mapping->i_pages)->xa_lock)->rlock){-...}, at: memfd_fcntl+0x4bc/0x1750
[   47.577123] 
[   47.577123] stack backtrace:
[   47.581615] CPU: 1 PID: 7632 Comm: syz-executor957 Not tainted 4.19.81 #0
[   47.588621] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   47.597965] Call Trace:
[   47.600572]  dump_stack+0x172/0x1f0
[   47.604972]  lockdep_rcu_suspicious+0x153/0x15d
[   47.609646]  memfd_fcntl+0xfdf/0x1750
[   47.613449]  ? vfs_write+0x2f0/0x560
[   47.617161]  ? find_held_lock+0x35/0x130
[   47.621224]  ? vfs_write+0x2f0/0x560
[   47.624945]  ? memfd_file_seals_ptr+0x160/0x160
[   47.629616]  ? check_preemption_disabled+0x48/0x290
[   47.634624]  do_fcntl+0x200/0x1020
[   47.638152]  ? f_getown+0xc0/0xc0
[   47.641592]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   47.647116]  ? ksys_write+0x1f1/0x2d0
[   47.650905]  ? __sanitizer_cov_trace_switch+0x49/0x80
[   47.656111]  ? selinux_file_fcntl+0x74/0x140
[   47.660514]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   47.666038]  ? security_file_fcntl+0x8d/0xc0
[   47.670437]  __x64_sys_fcntl+0x16d/0x1e0
[   47.674509]  do_syscall_64+0xfd/0x620
[   47.678325]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   47.683614] RIP: 0033:0x440169
[   47.686792] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
[   47.705703] RSP: 002b:00007fff3661e7d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000048
[   47.713667] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440169
[   47.720924] RDX: 0000000000000008 RSI: 0000000000000409 RDI: 0000000000000003
[   47.728205] RBP: 00000000006ca018