=============================
WARNING: suspicious RCU usage
4.15.0-rc9+ #284 Not tainted
-----------------------------
net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz-executor3/10345:
 #0:  (cb_lock){++++}, at: [<00000000aa3d1d47>] genl_rcv+0x19/0x40 net/netlink/genetlink.c:634
 #1:  (genl_mutex){+.+.}, at: [<00000000d67792a8>] genl_lock net/netlink/genetlink.c:33 [inline]
 #1:  (genl_mutex){+.+.}, at: [<00000000d67792a8>] genl_rcv_msg+0x115/0x140 net/netlink/genetlink.c:622

stack backtrace:
CPU: 0 PID: 10345 Comm: syz-executor3 Not tainted 4.15.0-rc9+ #284
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4587
 tipc_bearer_find+0x2b4/0x3b0 net/tipc/bearer.c:177
 tipc_nl_compat_link_set+0x329/0x9f0 net/tipc/netlink_compat.c:729
 __tipc_nl_compat_doit net/tipc/netlink_compat.c:288 [inline]
 tipc_nl_compat_doit+0x15b/0x670 net/tipc/netlink_compat.c:335
 tipc_nl_compat_handle net/tipc/netlink_compat.c:1119 [inline]
 tipc_nl_compat_recv+0x1135/0x18f0 net/tipc/netlink_compat.c:1201
 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:599
 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:624
 netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2409
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:635
 netlink_unicast_kernel net/netlink/af_netlink.c:1275 [inline]
 netlink_unicast+0x4ee/0x700 net/netlink/af_netlink.c:1301
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1864
 sock_sendmsg_nosec net/socket.c:638 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:648
 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2028
 __sys_sendmsg+0xe5/0x210 net/socket.c:2062
 SYSC_sendmsg net/socket.c:2073 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2069
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x453299
RSP: 002b:00007f62e6034c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f62e6035700 RCX: 0000000000453299
RDX: 0000000000000000 RSI: 0000000020003000 RDI: 0000000000000013
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f33f R14: 00007f62e60359c0 R15: 0000000000000000
netlink: 'syz-executor1': attribute type 3 has an invalid length.
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=256 sclass=netlink_route_socket pig=10355 comm=syz-executor2
netlink: 'syz-executor1': attribute type 3 has an invalid length.
device eql entered promiscuous mode
skbuff: bad partial csum: csum=0/65535 len=40
netlink: 12 bytes leftover after parsing attributes in process `syz-executor5'.
binder: 10678:10688 Acquire 1 refcount change on invalid ref 0 ret -22
binder: 10678:10707 Acquire 1 refcount change on invalid ref 0 ret -22
binder: 10678:10693 Acquire 1 refcount change on invalid ref 0 ret -22
9pnet_virtio: no channels available for device ./file0
9pnet_virtio: no channels available for device ./file0
device syz6 entered promiscuous mode