[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.128083] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.868997] random: sshd: uninitialized urandom read (32 bytes read) [ 23.161255] random: sshd: uninitialized urandom read (32 bytes read) [ 24.017517] random: sshd: uninitialized urandom read (32 bytes read) [ 241.120925] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.13' (ECDSA) to the list of known hosts. [ 246.640517] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 304.766400] random: crng init done executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 310.002258] bpfilter: read fail -512 [ 310.006144] [ 310.007798] ============================= [ 310.011989] WARNING: suspicious RCU usage [ 310.016233] 4.18.0-rc2+ #117 Not tainted [ 310.020302] ----------------------------- [ 310.024495] kernel/pid.c:323 suspicious rcu_dereference_check() usage! [ 310.031259] [ 310.031259] other info that might help us debug this: [ 310.031259] [ 310.039430] [ 310.039430] rcu_scheduler_active = 2, debug_locks = 1 [ 310.046095] 1 lock held by syz-executor106/7744: [ 310.050885] #0: 00000000bee82115 (bpfilter_lock){+.+.}, at: __bpfilter_process_sockopt+0x1c5/0x39b [ 310.060375] [ 310.060375] stack backtrace: [ 310.064923] CPU: 1 PID: 7744 Comm: syz-executor106 Not tainted 4.18.0-rc2+ #117 [ 310.072372] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 310.081778] Call Trace: [ 310.084397] dump_stack+0x1c9/0x2b4 [ 310.088095] ? dump_stack_print_info.cold.2+0x52/0x52 [ 310.093328] ? vprintk_func+0x81/0xe7 [ 310.097140] lockdep_rcu_suspicious+0x14a/0x153 [ 310.101830] pid_task+0x1ce/0x200 [ 310.105312] ? find_vpid+0xf0/0xf0 [ 310.108880] ? radix_tree_lookup+0x21/0x30 [ 310.113120] ? idr_find+0x44/0x50 [ 310.116579] shutdown_umh.constprop.0+0x33/0x7c [ 310.121250] __bpfilter_process_sockopt.cold.1+0x9b/0xa0 [ 310.126699] ? ipv6_mc_check_mld+0xf70/0xf70 [ 310.131098] ? do_raw_spin_unlock+0xa7/0x2f0 [ 310.135496] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 310.140063] ? __fget_light+0x2f7/0x440 [ 310.144017] ? ipv6_mc_check_mld+0xf70/0xf70 [ 310.148441] bpfilter_mbox_request+0x4d/0xb0 [ 310.152835] bpfilter_ip_set_sockopt+0x33/0x40 [ 310.157438] ip_setsockopt+0x124/0x140 [ 310.161336] dccp_setsockopt+0x96/0xf0 [ 310.165226] sock_common_setsockopt+0x9a/0xe0 [ 310.169837] __sys_setsockopt+0x1c5/0x3b0 [ 310.173983] ? kernel_accept+0x310/0x310 [ 310.178030] ? do_futex+0x27d0/0x27d0 [ 310.182234] __x64_sys_setsockopt+0xbe/0x150 [ 310.186644] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 310.191660] do_syscall_64+0x1b9/0x820 [ 310.195545] ? finish_task_switch+0x1d3/0x890 [ 310.200024] ? syscall_return_slowpath+0x5e0/0x5e0 [ 310.204933] ? syscall_return_slowpath+0x31d/0x5e0 [ 310.209882] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 310.215230] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 310.220059] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 310.225237] RIP: 0033:0x44cdb9 [ 310.228406] Code: e8 6c bd 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 cb d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 executing program [ 310.247695] RSP: 002b:00007f63b04a8d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 310.255399] RAX: ffffffffffffffda RBX: 00000000006dfce4 RCX: 000000000044cdb9 [ 310.262671] RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000027 [ 310.269930] RBP: 00000000006dfce0 R08: 0000000000000000 R09: 65732f636f72702f [ 310.277182] R10: 0000000020000000 R11: 0000000000000246 R12: 00007f63b04a8d20 [ 310.284431] R13: 0100000000000000 R14: 6273752f7665642f R15: 0000000000000034 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program