============================= WARNING: suspicious RCU usage 5.16.0-rc3-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/u4:5/19242: #0: ffff88806ebaa938 ((wq_completion)wg-kex-wg1#5){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140 #1: ffffc9000af1fd20 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2273 #2: ffff88806de5cc78 (&peer->endpoint_lock){++-.}-{2:2}, at: wg_socket_send_skb_to_peer+0x55/0x1d0 drivers/net/wireguard/socket.c:172 #3: ffffffff8cb1dba0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:268 #4: ffffffff8cb1dba0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:268 #5: ffffffff8cb1dba0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:268 stack backtrace: CPU: 1 PID: 19242 Comm: kworker/u4:5 Not tainted 5.16.0-rc3-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: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x201/0x2d8 lib/dump_stack.c:106 nf_hook_egress include/linux/netfilter_netdev.h:97 [inline] __dev_queue_xmit+0x33de/0x35c0 net/core/dev.c:4170 neigh_output include/net/neighbour.h:527 [inline] ip6_finish_output2+0xf07/0x14c0 net/ipv6/ip6_output.c:126 ip6tunnel_xmit include/net/ip6_tunnel.h:160 [inline] udp_tunnel6_xmit_skb+0x4d7/0x8f0 net/ipv6/ip6_udp_tunnel.c:109 send6+0x667/0xa90 drivers/net/wireguard/socket.c:152 wg_socket_send_skb_to_peer+0x111/0x1d0 drivers/net/wireguard/socket.c:177 wg_packet_send_handshake_initiation+0x211/0x310 drivers/net/wireguard/send.c:40 wg_packet_handshake_send_worker+0x18/0x30 drivers/net/wireguard/send.c:51 process_one_work+0x853/0x1140 kernel/workqueue.c:2298 worker_thread+0xac1/0x1320 kernel/workqueue.c:2445 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30