[....] 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 syzkaller login: [ 32.591893] random: sshd: uninitialized urandom read (32 bytes read) [ 32.813531] kauditd_printk_skb: 9 callbacks suppressed [ 32.813540] audit: type=1400 audit(1567257223.274:35): avc: denied { map } for pid=6833 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 [ 32.870386] random: sshd: uninitialized urandom read (32 bytes read) [ 33.391687] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.214' (ECDSA) to the list of known hosts. [ 39.022651] urandom_read: 1 callbacks suppressed [ 39.022656] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 39.142797] audit: type=1400 audit(1567257229.604:36): avc: denied { map } for pid=6846 comm="syz-executor501" path="/root/syz-executor501684069" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 39.148019] [ 39.169680] audit: type=1400 audit(1567257229.604:37): avc: denied { create } for pid=6846 comm="syz-executor501" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 [ 39.171403] ============================= [ 39.196928] audit: type=1400 audit(1567257229.604:38): avc: denied { write } for pid=6846 comm="syz-executor501" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 [ 39.201318] WARNING: suspicious RCU usage [ 39.225152] audit: type=1400 audit(1567257229.604:39): avc: denied { read } for pid=6846 comm="syz-executor501" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 [ 39.229531] 4.14.141 #37 Not tainted [ 39.257328] ----------------------------- [ 39.261565] net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage! [ 39.269107] [ 39.269107] other info that might help us debug this: [ 39.269107] [ 39.277805] [ 39.277805] rcu_scheduler_active = 2, debug_locks = 1 [ 39.284622] 2 locks held by syz-executor501/6846: [ 39.289452] #0: (cb_lock){++++}, at: [] genl_rcv+0x1a/0x40 [ 39.296906] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x119/0x150 [ 39.305127] [ 39.305127] stack backtrace: [ 39.309622] CPU: 0 PID: 6846 Comm: syz-executor501 Not tainted 4.14.141 #37 [ 39.316711] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.326232] Call Trace: [ 39.328826] dump_stack+0x138/0x197 [ 39.332440] lockdep_rcu_suspicious+0x153/0x15d [ 39.337113] tipc_bearer_find+0x20a/0x300 [ 39.341329] tipc_nl_compat_link_set+0x433/0xbf0 [ 39.346111] tipc_nl_compat_doit+0x1a2/0x550 [ 39.350503] ? security_capable+0x8e/0xc0 [ 39.354648] ? tipc_nl_compat_link_stat_dump+0x2080/0x2080 [ 39.360263] ? ns_capable_common+0x12c/0x160 [ 39.364649] ? ns_capable+0x23/0x30 [ 39.368267] ? __netlink_ns_capable+0xe2/0x130 [ 39.373097] tipc_nl_compat_recv+0x9ec/0xb20 [ 39.377509] ? is_bpf_text_address+0xa6/0x120 [ 39.382013] ? tipc_nl_compat_doit+0x550/0x550 [ 39.386592] ? tipc_nl_node_dump+0xc90/0xc90 [ 39.391013] ? tipc_nl_compat_bearer_enable+0x570/0x570 [ 39.396381] ? lock_acquire+0x16f/0x430 [ 39.400341] ? genl_rcv_msg+0x119/0x150 [ 39.404318] ? genl_rcv_msg+0x119/0x150 [ 39.408282] genl_family_rcv_msg+0x614/0xc30 [ 39.412676] ? genl_unregister_family+0x6a0/0x6a0 [ 39.417593] genl_rcv_msg+0xb4/0x150 [ 39.421286] netlink_rcv_skb+0x14f/0x3c0 [ 39.425326] ? genl_family_rcv_msg+0xc30/0xc30 [ 39.429902] ? netlink_ack+0x9a0/0x9a0 [ 39.433767] ? genl_rcv+0x1a/0x40 [ 39.437200] genl_rcv+0x29/0x40 [ 39.440458] netlink_unicast+0x45d/0x640 [ 39.444500] ? netlink_attachskb+0x6a0/0x6a0 [ 39.448892] ? security_netlink_send+0x81/0xb0 [ 39.453466] netlink_sendmsg+0x7c4/0xc60 [ 39.457602] ? netlink_unicast+0x640/0x640 [ 39.461819] ? security_socket_sendmsg+0x89/0xb0 [ 39.466990] ? netlink_unicast+0x640/0x640 [ 39.471310] sock_sendmsg+0xce/0x110 [ 39.475115] ___sys_sendmsg+0x70a/0x840 [ 39.479093] ? copy_msghdr_from_user+0x3f0/0x3f0 [ 39.483830] ? __lock_acquire+0x5f7/0x4620 [ 39.488162] ? save_trace+0x290/0x290 [ 39.491952] ? trace_hardirqs_on+0x10/0x10 [ 39.496168] ? save_trace+0x290/0x290 [ 39.499949] ? lock_downgrade+0x6e0/0x6e0 [ 39.504123] ? task_work_run+0xf0/0x190 [ 39.508083] ? __fget_light+0x172/0x1f0 [ 39.512034] ? __fdget+0x1b/0x20 [ 39.515444] ? sockfd_lookup_light+0xb4/0x160 [ 39.519924] __sys_sendmsg+0xb9/0x140 [ 39.523709] ? SyS_shutdown+0x170/0x170 [ 39.527806] ? trace_hardirqs_on_caller+0x400/0x590 [ 39.532813] SyS_sendmsg+0x2d/0x50 [ 39.536349] ? __sys_sendmsg+0x140/0x140 [ 39.540394] do_syscall_64+0x1e8/0x640 [ 39.544261] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.549143] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 39.554485] RIP: 0033:0x444229 [ 39.557658] RSP: 002b:00007ffdbd4fba88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 39.565344] RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444229 [ 39.572598] RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000003 [ 39.579861] RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0 [ 39.587119] R10: 0000000000001800 R11: 0000000000000246 R12: 0000000000401ed0 [ 3