====================================================== WARNING: possible circular locking dependency detected 5.5.0-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:4/509 is trying to acquire lock: ffff888097a30e80 (&wg->static_identity.lock){++++}, at: wg_noise_handshake_create_initiation+0x6a/0x15c0 drivers/net/wireguard/noise.c:499 but task is already holding lock: ffffc90002157d78 ((work_completion)(&peer->transmit_handshake_work)){+.+.}, at: process_one_work+0x7a5/0x10f0 kernel/workqueue.c:2239 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((work_completion)(&peer->transmit_handshake_work)){+.+.}: lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 process_one_work+0x7c8/0x10f0 kernel/workqueue.c:2240 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 -> #1 ((wq_completion)wg-kex-wireguard0){+.+.}: lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 flush_workqueue+0x10a/0x1820 kernel/workqueue.c:2775 peer_remove_after_dead+0x125/0x280 drivers/net/wireguard/peer.c:141 wg_peer_remove+0x211/0x270 drivers/net/wireguard/peer.c:176 wg_set_device+0xb6a/0x2010 drivers/net/wireguard/netlink.c:575 genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline] genl_family_rcv_msg net/netlink/genetlink.c:717 [inline] genl_rcv_msg+0xf15/0x13e0 net/netlink/genetlink.c:734 netlink_rcv_skb+0x19e/0x3e0 net/netlink/af_netlink.c:2477 genl_rcv+0x28/0x40 net/netlink/genetlink.c:745 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x766/0x920 net/netlink/af_netlink.c:1328 netlink_sendmsg+0xa2b/0xd40 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x4f7/0x7f0 net/socket.c:2343 ___sys_sendmsg net/socket.c:2397 [inline] __sys_sendmsg+0x1ed/0x290 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2437 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&wg->static_identity.lock){++++}: check_prev_add kernel/locking/lockdep.c:2475 [inline] check_prevs_add kernel/locking/lockdep.c:2580 [inline] validate_chain+0x1507/0x7be0 kernel/locking/lockdep.c:2970 __lock_acquire+0xc5a/0x1bc0 kernel/locking/lockdep.c:3954 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 down_read+0x39/0x50 kernel/locking/rwsem.c:1495 wg_noise_handshake_create_initiation+0x6a/0x15c0 drivers/net/wireguard/noise.c:499 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0xe5/0x1a0 drivers/net/wireguard/send.c:51 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 other info that might help us debug this: Chain exists of: &wg->static_identity.lock --> (wq_completion)wg-kex-wireguard0 --> (work_completion)(&peer->transmit_handshake_work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&peer->transmit_handshake_work)); lock((wq_completion)wg-kex-wireguard0); lock((work_completion)(&peer->transmit_handshake_work)); lock(&wg->static_identity.lock); *** DEADLOCK *** 2 locks held by kworker/u4:4/509: #0: ffff88809ec44128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff88809ec44128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: process_one_work+0x763/0x10f0 kernel/workqueue.c:2237 #1: ffffc90002157d78 ((work_completion)(&peer->transmit_handshake_work)){+.+.}, at: process_one_work+0x7a5/0x10f0 kernel/workqueue.c:2239 stack backtrace: CPU: 1 PID: 509 Comm: kworker/u4:4 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: wg-kex-wireguard0 wg_packet_handshake_send_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fb/0x318 lib/dump_stack.c:118 print_circular_bug+0xc3f/0xe70 kernel/locking/lockdep.c:1684 check_noncircular+0x206/0x3a0 kernel/locking/lockdep.c:1808 check_prev_add kernel/locking/lockdep.c:2475 [inline] check_prevs_add kernel/locking/lockdep.c:2580 [inline] validate_chain+0x1507/0x7be0 kernel/locking/lockdep.c:2970 __lock_acquire+0xc5a/0x1bc0 kernel/locking/lockdep.c:3954 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 down_read+0x39/0x50 kernel/locking/rwsem.c:1495 wg_noise_handshake_create_initiation+0x6a/0x15c0 drivers/net/wireguard/noise.c:499 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0xe5/0x1a0 drivers/net/wireguard/send.c:51 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352