[....] Starting OpenBSD Secure Shell server: sshd[ 12.230919] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.969629] random: sshd: uninitialized urandom read (32 bytes read) [ 17.236747] audit: type=1400 audit(1572742172.553:6): avc: denied { map } for pid=1760 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 17.301573] random: sshd: uninitialized urandom read (32 bytes read) [ 17.834450] random: sshd: uninitialized urandom read (32 bytes read) [ 17.990904] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.30' (ECDSA) to the list of known hosts. [ 23.438730] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 23.532836] audit: type=1400 audit(1572742178.853:7): avc: denied { map } for pid=1778 comm="syz-executor259" path="/root/syz-executor259677610" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 23.534587] [ 23.560735] ============================= [ 23.564866] WARNING: suspicious RCU usage [ 23.568988] 4.14.151+ #0 Not tainted [ 23.572676] ----------------------------- [ 23.576799] ./include/linux/radix-tree.h:238 suspicious rcu_dereference_check() usage! [ 23.584826] [ 23.584826] other info that might help us debug this: [ 23.584826] [ 23.592977] [ 23.592977] rcu_scheduler_active = 2, debug_locks = 1 [ 23.599617] 2 locks held by syz-executor259/1778: [ 23.604432] #0: (&sb->s_type->i_mutex_key#10){+.+.}, at: [< (ptrval)>] shmem_add_seals+0x12b/0xf80 [ 23.614318] #1: (&(&mapping->tree_lock)->rlock){-...}, at: [< (ptrval)>] shmem_add_seals+0x2e1/0xf80 [ 23.624371] [ 23.624371] stack backtrace: [ 23.628856] CPU: 1 PID: 1778 Comm: syz-executor259 Not tainted 4.14.151+ #0 [ 23.636017] Call Trace: [ 23.638596] dump_stack+0xca/0x134 [ 23.642118] shmem_add_seals+0x9d2/0xf80 [ 23.646164] ? shmem_file_llseek+0x220/0x220 [ 23.650552] ? vfs_write+0x35d/0x4d0 [ 23.654243] ? check_preemption_disabled+0x35/0x1f0 [ 23.659252] shmem_fcntl+0xea/0x120 [ 23.662858] do_fcntl+0x5c8/0xd20 [ 23.666301] ? f_getown+0xa0/0xa0 [ 23.669742] ? vfs_write+0x319/0x4d0 [ 23.673438] ? selinux_file_fcntl+0x86/0x140 [ 23.677829] SyS_fcntl+0xc6/0x100 [ 23.681259] ? do_fcntl+0xd20/0xd20 [ 23.684876] do_syscall_64+0x19b/0x520 [ 23.688758] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 23.693925] RIP: 0033:0x440189 [ 23.697091] RSP: 002b:00007fff24d032c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000048 [ 23.704775] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440189 [ 23.712021] RDX: 0000000000000008 RSI: 0000000000000409 RDI: 0000000000000003 [ 23.719268] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 [ 23.726520] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a10