[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 31.059149] random: sshd: uninitialized urandom read (32 bytes read) [ 31.256557] kauditd_printk_skb: 10 callbacks suppressed [ 31.256606] audit: type=1400 audit(1582348857.077:35): avc: denied { map } for pid=7200 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 [ 31.312686] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 32.010167] random: sshd: uninitialized urandom read (32 bytes read) [ 32.198921] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.128' (ECDSA) to the list of known hosts. [ 37.798809] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 37.913672] audit: type=1400 audit(1582348863.737:36): avc: denied { map } for pid=7214 comm="syz-executor130" path="/root/syz-executor130548078" 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 [ 37.916766] [ 37.941913] ============================= [ 37.946046] WARNING: suspicious RCU usage [ 37.950808] 4.14.171-syzkaller #0 Not tainted [ 37.955299] ----------------------------- [ 37.959515] net/sched/act_sample.c:95 suspicious rcu_dereference_protected() usage! [ 37.967608] [ 37.967608] other info that might help us debug this: [ 37.967608] [ 37.976104] [ 37.976104] rcu_scheduler_active = 2, debug_locks = 1 [ 37.982871] 1 lock held by syz-executor130/7214: [ 37.987767] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x339/0xb70 [ 37.996514] [ 37.996514] stack backtrace: [ 38.001123] CPU: 1 PID: 7214 Comm: syz-executor130 Not tainted 4.14.171-syzkaller #0 [ 38.009001] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.018345] Call Trace: [ 38.020920] dump_stack+0x142/0x197 [ 38.024529] ? e1000_netpoll+0x480/0x580 [ 38.028609] lockdep_rcu_suspicious+0x153/0x15d [ 38.033279] tcf_sample_init+0x783/0x960 [ 38.037337] ? tcf_sample_act+0x9f0/0x9f0 [ 38.041542] ? rcu_read_lock_sched_held+0x110/0x130 [ 38.046634] ? _raw_read_unlock+0x2d/0x50 [ 38.050784] tcf_action_init_1+0x53c/0xaa0 [ 38.055070] ? tcf_action_dump_old+0x80/0x80 [ 38.059461] ? lock_downgrade+0x740/0x740 [ 38.063605] ? nla_parse+0x186/0x240 [ 38.067305] tcf_action_init+0x2ab/0x480 [ 38.071368] ? tcf_action_init_1+0xaa0/0xaa0 [ 38.075781] ? memset+0x32/0x40 [ 38.079070] ? nla_parse+0x186/0x240 [ 38.082779] tc_ctl_action+0x30a/0x548 [ 38.086674] ? tca_action_gd+0x840/0x840 [ 38.090735] ? tca_action_gd+0x840/0x840 [ 38.094985] rtnetlink_rcv_msg+0x3da/0xb70 [ 38.099207] ? rtnl_bridge_getlink+0x7a0/0x7a0 [ 38.103783] ? netlink_deliver_tap+0x93/0x8f0 [ 38.108275] netlink_rcv_skb+0x14f/0x3c0 [ 38.112328] ? rtnl_bridge_getlink+0x7a0/0x7a0 [ 38.116929] ? lock_downgrade+0x740/0x740 [ 38.121084] ? netlink_ack+0x9a0/0x9a0 [ 38.124967] ? netlink_deliver_tap+0xba/0x8f0 [ 38.129454] rtnetlink_rcv+0x1d/0x30 [ 38.133149] netlink_unicast+0x44d/0x650 [ 38.137364] ? netlink_attachskb+0x6a0/0x6a0 [ 38.141827] ? security_netlink_send+0x81/0xb0 [ 38.146404] netlink_sendmsg+0x7c4/0xc60 [ 38.150460] ? netlink_unicast+0x650/0x650 [ 38.154689] ? security_socket_sendmsg+0x89/0xb0 [ 38.159438] ? netlink_unicast+0x650/0x650 [ 38.163708] sock_sendmsg+0xce/0x110 [ 38.167419] ___sys_sendmsg+0x70a/0x840 [ 38.171384] ? lock_downgrade+0x740/0x740 [ 38.175518] ? copy_msghdr_from_user+0x3f0/0x3f0 [ 38.180251] ? do_raw_spin_unlock+0x174/0x260 [ 38.184980] ? _raw_spin_unlock+0x2d/0x50 [ 38.189135] ? do_huge_pmd_anonymous_page+0x2f9/0x1200 [ 38.194408] ? prep_transhuge_page+0xa0/0xa0 [ 38.198804] ? __handle_mm_fault+0x692/0x33d0 [ 38.203388] ? save_trace+0x290/0x290 [ 38.207203] ? copy_page_range+0x1de0/0x1de0 [ 38.211769] ? __do_page_fault+0x4e9/0xb80 [ 38.215998] ? __fget_light+0x172/0x1f0 [ 38.219962] ? __fdget+0x1b/0x20 [ 38.223333] ? sockfd_lookup_light+0xb4/0x160 [ 38.227813] __sys_sendmsg+0xb9/0x140 [ 38.231608] ? SyS_shutdown+0x170/0x170 [ 38.235573] SyS_sendmsg+0x2d/0x50 [ 38.239137] ? __sys_sendmsg+0x140/0x140 [ 38.243193] do_syscall_64+0x1e8/0x640 [ 38.247072] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 38.251902] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 38.257088] RIP: 0033:0x440369 [ 38.260259] RSP: 002b:00007ffffca468a8 EFLAGS: 00000246