=============================
WARNING: suspicious RCU usage
4.14.111+ #52 Not tainted
-----------------------------
net/ipv6/ip6_fib.c:1590 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz-executor.3/1166:
 #0:  (rtnl_mutex){+.+.}, at: [<00000000763a8554>] devinet_ioctl+0x17f/0x15c0 net/ipv4/devinet.c:1006
 #1:  (rcu_read_lock){....}, at: [<000000001aeb40c0>] __fib6_clean_all+0x0/0x230 net/ipv6/ip6_fib.c:1823
 #2:  (&tb->tb6_lock){++--}, at: [<00000000f90de74c>] __fib6_clean_all+0xde/0x230 net/ipv6/ip6_fib.c:1837

stack backtrace:
CPU: 1 PID: 1166 Comm: syz-executor.3 Not tainted 4.14.111+ #52
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 fib6_del+0x8c2/0xbe0 net/ipv6/ip6_fib.c:1590
 fib6_clean_node+0x270/0x440 net/ipv6/ip6_fib.c:1777
 fib6_walk_continue+0x3a5/0x5f0 net/ipv6/ip6_fib.c:1703
 fib6_walk+0x8d/0xe0 net/ipv6/ip6_fib.c:1748
 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:1822
 __fib6_clean_all+0xf5/0x230 net/ipv6/ip6_fib.c:1838
 rt6_ifdown+0x90/0x5b0 net/ipv6/route.c:2868
 addrconf_ifdown+0xc5/0x13b0 net/ipv6/addrconf.c:3602
SELinux:  Context system_u:object_r:ld_so_t:s0 is not valid (left unmapped).
A link change request failed with some changes committed already. Interface ip6tnl0 may have been left with an inconsistent configuration, please check.
A link change request failed with some changes committed already. Interface ip6tnl0 may have been left with an inconsistent configuration, please check.