syzbot

audit: type=1400 audit(1514690139.061:8): avc:  denied  { create } for  pid=3193 comm="syzkaller015658" 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

=============================
WARNING: suspicious RCU usage
4.15.0-rc5+ #243 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 syzkaller015658/3193:
 #0:  (cb_lock){++++}, at: [<00000000a19a66ca>] genl_rcv+0x19/0x40 net/netlink/genetlink.c:634
 #1:  (genl_mutex){+.+.}, at: [<000000000ac1cc6d>] genl_lock net/netlink/genetlink.c:33 [inline]
 #1:  (genl_mutex){+.+.}, at: [<000000000ac1cc6d>] genl_rcv_msg+0x115/0x140 net/netlink/genetlink.c:622

stack backtrace:
CPU: 1 PID: 3193 Comm: syzkaller015658 Not tainted 4.15.0-rc5+ #243
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:4585
 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/0x660 net/tipc/netlink_compat.c:335