[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 32.664403] random: sshd: uninitialized urandom read (32 bytes read) [ 32.932267] kauditd_printk_skb: 10 callbacks suppressed [ 32.932276] audit: type=1400 audit(1578310030.907:35): avc: denied { map } for pid=7078 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 [ 32.990975] random: sshd: uninitialized urandom read (32 bytes read) [ 33.640489] random: sshd: uninitialized urandom read (32 bytes read) [ 49.284113] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.52' (ECDSA) to the list of known hosts. [ 54.823532] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 54.943381] audit: type=1400 audit(1578310052.917:36): avc: denied { map } for pid=7091 comm="syz-executor204" path="/root/syz-executor204034520" 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 [ 55.024968] [ 55.026648] ===================================== [ 55.031688] WARNING: bad unlock balance detected! [ 55.036938] 4.14.162-syzkaller #0 Not tainted [ 55.041535] ------------------------------------- [ 55.046591] syz-executor204/7111 is trying to release lock (sk_lock-AF_INET6) at: [ 55.054214] [] gtp_encap_enable_socket+0x10c/0x360 [ 55.061552] but there are no more locks to release! [ 55.066725] [ 55.066725] other info that might help us debug this: [ 55.074403] 2 locks held by syz-executor204/7111: [ 55.079247] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x339/0xb70 [ 55.087823] #1: (slock-AF_INET6){+...}, at: [] release_sock+0x20/0x1b0 [ 55.097050] [ 55.097050] stack backtrace: [ 55.101537] CPU: 1 PID: 7111 Comm: syz-executor204 Not tainted 4.14.162-syzkaller #0 [ 55.109522] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.119735] Call Trace: [ 55.122532] dump_stack+0x142/0x197 [ 55.128211] ? gtp_encap_enable_socket+0x10c/0x360 [ 55.135399] print_unlock_imbalance_bug.cold+0x114/0x123 [ 55.141364] ? gtp_encap_enable_socket+0x10c/0x360 [ 55.146654] lock_release+0x616/0x940 [ 55.150453] ? lock_acquire+0x1ea/0x430 [ 55.154507] ? lock_downgrade+0x740/0x740 [ 55.158828] release_sock+0x175/0x1b0 [ 55.162702] gtp_encap_enable_socket+0x10c/0x360 [ 55.167555] ? gtp_find_dev+0x1e0/0x1e0 [ 55.171843] ? alloc_netdev_mqs+0x918/0xbc0 [ 55.176165] gtp_newlink+0x99f/0xc50 [ 55.180103] ? rtnl_create_link+0x12c/0x850 [ 55.184828] ? __netlink_ns_capable+0xe2/0x130 [ 55.189660] rtnl_newlink+0xecb/0x1700 [ 55.193579] ? gtp_genl_new_pdp+0xfe0/0xfe0 [ 55.198246] ? rtnl_link_unregister+0x200/0x200 [ 55.203119] ? avc_has_perm_noaudit+0x2b2/0x420 [ 55.208092] ? lock_acquire+0x16f/0x430 [ 55.212208] ? rtnetlink_rcv_msg+0x339/0xb70 [ 55.216699] ? rtnl_link_unregister+0x200/0x200 [ 55.221514] rtnetlink_rcv_msg+0x3da/0xb70 [ 55.225907] ? rtnl_bridge_getlink+0x7a0/0x7a0 [ 55.230544] ? netlink_deliver_tap+0x93/0x8f0 [ 55.235948] netlink_rcv_skb+0x14f/0x3c0 [ 55.240164] ? rtnl_bridge_getlink+0x7a0/0x7a0 [ 55.244794] ? lock_downgrade+0x740/0x740 [ 55.249593] ? netlink_ack+0x9a0/0x9a0 [ 55.253609] ? netlink_deliver_tap+0xba/0x8f0 [ 55.258422] rtnetlink_rcv+0x1d/0x30 [ 55.262538] netlink_unicast+0x44d/0x650 [ 55.266597] ? netlink_attachskb+0x6a0/0x6a0 [ 55.271545] ? security_netlink_send+0x81/0xb0 [ 55.276554] netlink_sendmsg+0x7c4/0xc60 [ 55.280836] ? netlink_unicast+0x650/0x650 [ 55.285365] ? security_socket_sendmsg+0x89/0xb0 [ 55.290204] ? netlink_unicast+0x650/0x650 [ 55.294637] sock_sendmsg+0xce/0x110 [ 55.298392] ___sys_sendmsg+0x70a/0x840 [ 55.302399] ? copy_msghdr_from_user+0x3f0/0x3f0 [ 55.307862] ? __fget+0x210/0x370 [ 55.311473] ? find_held_lock+0x35/0x130 [ 55.315662] ? __fget+0x210/0x370 [ 55.319444] ? lock_downgrade+0x740/0x740 [ 55.323593] ? __fget+0x237/0x370 [ 55.327400] ? __fget_light+0x172/0x1f0 [ 55.331549] ? __fdget+0x1b/0x20 [ 55.334943] ? sockfd_lookup_light+0xb4/0x160 [ 55.339464] __sys_sendmsg+0xb9/0x140 [ 55.343261] ? SyS_shutdown+0x170/0x170 [ 55.347315] SyS_sendmsg+0x2d/0x50 [ 55.350981] ? __sys_sendmsg+0x140/0x140 [ 55.355147] do_syscall_64+0x1e8/0x640 [ 55.359057] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 55.364115] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 55.369414] RIP: 0033:0x446ce9 [ 55.372594] RSP: 002b:00007fa109c79db8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 55.380791] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 0000000000446ce9 [ 55.388751] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003 [ 55.396022] RBP: 00000000006dbc30 R08: 0000000000000004 R09: 0000000000000000 [ 55.403562] R10: 0000000000000008 R11: 0000000000000246 R12: 00000000006dbc3c [ 55.411184] R13: 00007ffd6eefd73f R14: 00007fa109c7a9c0 R15: 000000000000002d executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program