Warning: Permanently added '10.128.10.56' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 33.515371] audit: type=1400 audit(1587474959.604:9): avc: denied { execmem } for pid=6353 comm="syz-executor758" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 33.519108] [ 33.537215] ============================= [ 33.541707] WARNING: suspicious RCU usage [ 33.546781] 4.14.176-syzkaller #0 Not tainted [ 33.551330] ----------------------------- [ 33.556786] net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage! [ 33.564515] [ 33.564515] other info that might help us debug this: [ 33.564515] [ 33.572741] [ 33.572741] rcu_scheduler_active = 2, debug_locks = 1 [ 33.579410] 2 locks held by syz-executor758/6353: [ 33.584834] #0: (cb_lock){++++}, at: [] genl_rcv+0x15/0x40 [ 33.592294] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x112/0x140 [ 33.600496] [ 33.600496] stack backtrace: [ 33.604978] CPU: 1 PID: 6353 Comm: syz-executor758 Not tainted 4.14.176-syzkaller #0 [ 33.612921] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.622255] Call Trace: [ 33.624840] dump_stack+0x13e/0x194 [ 33.628445] tipc_bearer_find+0x1ff/0x2f0 [ 33.632572] tipc_nl_compat_link_set+0x41f/0xbc0 [ 33.637325] tipc_nl_compat_doit+0x18d/0x510 [ 33.641711] ? tipc_nl_compat_link_stat_dump+0x1c40/0x1c40 [ 33.647313] ? cap_capable+0x1c4/0x230 [ 33.651341] ? security_capable+0x88/0xb0 [ 33.655486] ? ns_capable_common+0x127/0x150 [ 33.659883] tipc_nl_compat_recv+0x95c/0xa10 [ 33.664290] ? tipc_nl_compat_doit+0x510/0x510 [ 33.668852] ? tipc_nl_node_dump+0xc60/0xc60 [ 33.673240] ? tipc_nl_compat_bearer_enable+0x560/0x560 [ 33.678581] ? lock_acquire+0x170/0x3f0 [ 33.682550] ? genl_rcv_msg+0x112/0x140 [ 33.686500] genl_family_rcv_msg+0x57c/0xb30 [ 33.690890] ? pick_next_task_stop+0x1d1/0x1f0 [ 33.695468] ? genl_unregister_family+0x640/0x640 [ 33.700422] ? mutex_trylock+0x1a0/0x1a0 [ 33.704484] genl_rcv_msg+0xaf/0x140 [ 33.708194] netlink_rcv_skb+0x127/0x370 [ 33.712250] ? genl_family_rcv_msg+0xb30/0xb30 [ 33.716812] ? netlink_ack+0x980/0x980 [ 33.720679] ? lock_acquire+0x170/0x3f0 [ 33.724632] genl_rcv+0x24/0x40 [ 33.727901] netlink_unicast+0x437/0x620 [ 33.731943] ? netlink_attachskb+0x600/0x600 [ 33.736332] netlink_sendmsg+0x733/0xbe0 [ 33.740397] ? netlink_unicast+0x620/0x620 [ 33.744965] ? SYSC_sendto+0x2b0/0x2b0 [ 33.749719] ? security_socket_sendmsg+0x83/0xb0 [ 33.754452] ? netlink_unicast+0x620/0x620 [ 33.758663] sock_sendmsg+0xc5/0x100 [ 33.762356] ___sys_sendmsg+0x70a/0x840 [ 33.766305] ? copy_msghdr_from_user+0x380/0x380 [ 33.771038] ? lock_downgrade+0x6e0/0x6e0 [ 33.775162] ? __lock_acquire+0x5f7/0x4620 [ 33.779379] ? trace_hardirqs_on+0x10/0x10 [ 33.783594] ? trace_hardirqs_on+0x10/0x10 [ 33.787819] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 33.793266] ? save_trace+0x290/0x290 [ 33.797061] ? find_held_lock+0x2d/0x110 [ 33.801189] ? __fget_light+0x16a/0x1f0 [ 33.805139] ? sockfd_lookup_light+0xb2/0x160 [ 33.809629] __sys_sendmsg+0xa3/0x120 [ 33.813424] ? SyS_shutdown+0x160/0x160 [ 33.817479] ? _raw_spin_unlock_irq+0x24/0x80 [ 33.822047] SyS_sendmsg+0x27/0x40 [ 33.825725] ? __sys_sendmsg+0x120/0x120 [ 33.829884] do_syscall_64+0x1d5/0x640 [ 33.833763] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 33.838950] RIP: 0033:0x444279 [ 33.842125] RSP: 002b:00007ffd4477aef8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 33.849822] RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444279 [ 33.857107] RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000003 [ 33.865147] RBP: 00