=============================
WARNING: suspicious RCU usage
5.16.0-rc8-syzkaller #0 Not tainted
-----------------------------
include/linux/netfilter_netdev.h:97 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
6 locks held by kworker/u4:2/44:
 #0: ffff88807bf0d138 ((wq_completion)wg-kex-wg1){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88807bf0d138 ((wq_completion)wg-kex-wg1){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff88807bf0d138 ((wq_completion)wg-kex-wg1){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff88807bf0d138 ((wq_completion)wg-kex-wg1){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
 #0: ffff88807bf0d138 ((wq_completion)wg-kex-wg1){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
 #0: ffff88807bf0d138 ((wq_completion)wg-kex-wg1){+.+.}-{0:0}, at: process_one_work+0x896/0x1660 kernel/workqueue.c:2269
 #1: ffffc9000114fdb0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1660 kernel/workqueue.c:2273
 #2: ffff88804eb60178 (&peer->endpoint_lock){++-.}-{2:2}, at: wg_socket_send_skb_to_peer+0x5e/0x220 drivers/net/wireguard/socket.c:172
 #3: ffffffff8bb83d40 (rcu_read_lock_bh){....}-{1:2}, at: send6+0x2db/0xcc0 drivers/net/wireguard/socket.c:116
 #4: ffffffff8bb83d40 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline]
 #4: ffffffff8bb83d40 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x2ad/0x14f0 net/ipv6/ip6_output.c:112
 #5: ffffffff8bb83d40 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3640 net/core/dev.c:4040

stack backtrace:
CPU: 0 PID: 44 Comm: kworker/u4:2 Not tainted 5.16.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nf_hook_egress include/linux/netfilter_netdev.h:97 [inline]
 __dev_queue_xmit+0x2eac/0x3640 net/core/dev.c:4057
 neigh_hh_output include/net/neighbour.h:525 [inline]
 neigh_output include/net/neighbour.h:539 [inline]
 ip6_finish_output2+0xf76/0x14f0 net/ipv6/ip6_output.c:126
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 __ip6_finish_output+0x61e/0xe80 net/ipv6/ip6_output.c:170
 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224
 dst_output include/net/dst.h:451 [inline]
 ip6_local_out+0xaf/0x1a0 net/ipv6/output_core.c:161
 ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline]
 udp_tunnel6_xmit_skb+0x72e/0xc90 net/ipv6/ip6_udp_tunnel.c:109
 send6+0x4ab/0xcc0 drivers/net/wireguard/socket.c:152
 wg_socket_send_skb_to_peer+0xf5/0x220 drivers/net/wireguard/socket.c:177
 wg_socket_send_buffer_to_peer+0x127/0x170 drivers/net/wireguard/socket.c:199
 wg_packet_send_handshake_initiation+0x212/0x340 drivers/net/wireguard/send.c:40
 wg_packet_handshake_send_worker+0x18/0x30 drivers/net/wireguard/send.c:51
 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298
 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>