====================================================== WARNING: possible circular locking dependency detected 5.5.0-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:12/8466 is trying to acquire lock: ffff888054c24e80 (&wg->static_identity.lock){++++}, at: wg_noise_handshake_create_initiation+0xc0/0x670 drivers/net/wireguard/noise.c:499 but task is already holding lock: ffffc90008927dc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}, at: process_one_work+0x917/0x17a0 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)){+.+.}: process_one_work+0x972/0x17a0 kernel/workqueue.c:2240 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 -> #1 ((wq_completion)wg-kex-wireguard0){+.+.}: flush_workqueue+0x126/0x14c0 kernel/workqueue.c:2775 peer_remove_after_dead+0x16b/0x230 drivers/net/wireguard/peer.c:141 wg_peer_remove+0x244/0x340 drivers/net/wireguard/peer.c:176 wg_set_device+0xf76/0x1350 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+0x67d/0xea0 net/netlink/genetlink.c:734 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 genl_rcv+0x29/0x40 net/netlink/genetlink.c:745 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 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 kernel/locking/lockdep.c:2970 [inline] __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3954 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4484 down_read+0x95/0x430 kernel/locking/rwsem.c:1495 wg_noise_handshake_create_initiation+0xc0/0x670 drivers/net/wireguard/noise.c:499 wg_packet_send_handshake_initiation+0x185/0x250 drivers/net/wireguard/send.c:34 wg_packet_handshake_send_worker+0x1d/0x30 drivers/net/wireguard/send.c:51 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 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/u4:12/8466: #0: ffff88805538b128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff88805538b128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88805538b128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff88805538b128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff88805538b128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88805538b128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88805538b128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2235 #1: ffffc90008927dc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2239 stack backtrace: CPU: 1 PID: 8466 Comm: kworker/u4:12 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+0x197/0x210 lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x163/0x172 kernel/locking/lockdep.c:1684 check_noncircular+0x32e/0x3e0 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 kernel/locking/lockdep.c:2970 [inline] __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3954 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4484 down_read+0x95/0x430 kernel/locking/rwsem.c:1495 wg_noise_handshake_create_initiation+0xc0/0x670 drivers/net/wireguard/noise.c:499 wg_packet_send_handshake_initiation+0x185/0x250 drivers/net/wireguard/send.c:34 wg_packet_handshake_send_worker+0x1d/0x30 drivers/net/wireguard/send.c:51 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352