Warning: Permanently added '10.128.0.167' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 31.942786] [ 31.944672] ============================= [ 31.948887] WARNING: suspicious RCU usage [ 31.953047] 4.14.216-syzkaller #0 Not tainted [ 31.958945] ----------------------------- [ 31.963116] net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage! [ 31.971247] [ 31.971247] other info that might help us debug this: [ 31.971247] [ 31.979826] [ 31.979826] rcu_scheduler_active = 2, debug_locks = 1 [ 31.987154] 2 locks held by syz-executor143/7991: [ 31.991987] #0: (cb_lock){++++}, at: [] genl_rcv+0x15/0x40 [ 32.000217] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x112/0x140 [ 32.008572] [ 32.008572] stack backtrace: [ 32.013074] CPU: 1 PID: 7991 Comm: syz-executor143 Not tainted 4.14.216-syzkaller #0 [ 32.020929] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.030257] Call Trace: [ 32.032825] dump_stack+0x1b2/0x281 [ 32.036443] tipc_bearer_find+0x1ff/0x2f0 [ 32.040572] tipc_nl_compat_link_set+0x40b/0xb90 [ 32.045303] ? __alloc_skb+0x3dc/0x510 [ 32.049185] tipc_nl_compat_doit+0x192/0x5d0 [ 32.053586] ? tipc_nl_compat_link_set+0xb90/0xb90 [ 32.058511] ? security_capable+0x88/0xb0 [ 32.062638] ? ns_capable_common+0x127/0x150 [ 32.067063] tipc_nl_compat_recv+0xa0b/0xae0 [ 32.071480] ? tipc_nl_compat_dumpit+0x7a0/0x7a0 [ 32.076211] ? tipc_nl_node_dump+0xc20/0xc20 [ 32.080599] ? __tipc_add_link_prop.isra.0+0x190/0x190 [ 32.085874] ? lock_downgrade+0x740/0x740 [ 32.090005] genl_family_rcv_msg+0x572/0xb20 [ 32.094408] ? __lock_acquire+0x5fc/0x3f20 [ 32.098620] ? genl_rcv+0x40/0x40 [ 32.102051] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 32.107506] ? trace_hardirqs_on+0x10/0x10 [ 32.111920] ? sock_sendmsg+0xb5/0x100 [ 32.116573] genl_rcv_msg+0xaf/0x140 [ 32.120266] netlink_rcv_skb+0x125/0x390 [ 32.124317] ? genl_family_rcv_msg+0xb20/0xb20 [ 32.128882] ? netlink_ack+0x9a0/0x9a0 [ 32.132746] ? lock_acquire+0x170/0x3f0 [ 32.136700] genl_rcv+0x24/0x40 [ 32.139957] netlink_unicast+0x437/0x610 [ 32.144011] ? netlink_sendskb+0xd0/0xd0 [ 32.148059] ? __check_object_size+0x179/0x230 [ 32.152618] netlink_sendmsg+0x62e/0xb80 [ 32.156690] ? nlmsg_notify+0x170/0x170 [ 32.160643] ? kernel_recvmsg+0x210/0x210 [ 32.164808] ? security_socket_sendmsg+0x83/0xb0 [ 32.169539] ? nlmsg_notify+0x170/0x170 [ 32.173521] sock_sendmsg+0xb5/0x100 [ 32.177238] ___sys_sendmsg+0x6c8/0x800 [ 32.181212] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 32.185958] ? trace_hardirqs_on+0x10/0x10 [ 32.190181] ? trace_hardirqs_on+0x10/0x10 [ 32.194409] ? apparmor_file_alloc_security+0x129/0x800 [ 32.199767] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 32.205211] ? __lockdep_init_map+0x100/0x560 [ 32.209682] ? __fd_install+0x1ec/0x5c0 [ 32.213630] ? lock_acquire+0x170/0x3f0 [ 32.217581] ? lock_downgrade+0x740/0x740 [ 32.221706] ? __fdget+0x167/0x1f0 [ 32.225224] ? sockfd_lookup_light+0xb2/0x160 [ 32.229694] __sys_sendmsg+0xa3/0x120 [ 32.233482] ? SyS_shutdown+0x160/0x160 [ 32.237437] ? move_addr_to_kernel+0x60/0x60 [ 32.241820] SyS_sendmsg+0x27/0x40 [ 32.245339] ? __sys_sendmsg+0x120/0x120 [ 32.249388] do_syscall_64+0x1d5/0x640 [ 32.253257] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.258436] RIP: 0033:0x440979 [ 32.261603] RSP: 002b:00007ffddd68f9d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 32.269299] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440979 [ 32.276543] RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000000000003 [ 32.283802] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 [ 32.291046] R10: 0000000000001800 R1