============================================ WARNING: possible recursive locking detected 6.14.0-syzkaller-g8582d9ab3efd #0 Not tainted -------------------------------------------- kworker/1:1/52 is trying to acquire lock: ffffc9001bfd90d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20e/0x650 kernel/bpf/ringbuf.c:423 but task is already holding lock: ffffc9001ba230d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20e/0x650 kernel/bpf/ringbuf.c:423 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&rb->spinlock); lock(&rb->spinlock); *** DEADLOCK *** May be due to missing lock nesting notation 9 locks held by kworker/1:1/52: #0: ffff88807e75e548 ((wq_completion)wg-crypt-wg1#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88807e75e548 ((wq_completion)wg-crypt-wg1#2){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000bd7c60 ((work_completion)(&peer->transmit_packet_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bd7c60 ((work_completion)(&peer->transmit_packet_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff88805acbbce8 (&peer->endpoint_lock){++-.}-{3:3}, at: wg_socket_send_skb_to_peer+0x5a/0x1d0 drivers/net/wireguard/socket.c:173 #3: ffffffff8ed3dfc0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8ed3dfc0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #3: ffffffff8ed3dfc0 (rcu_read_lock_bh){....}-{1:3}, at: send6+0x2d4/0xbf0 drivers/net/wireguard/socket.c:118 #4: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x1750 net/ipv6/ip6_output.c:126 #5: ffffffff8ed3dfc0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #5: ffffffff8ed3dfc0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #5: ffffffff8ed3dfc0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f9/0x3f60 net/core/dev.c:4558 #6: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #6: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #6: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2362 [inline] #6: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x246/0x5a0 kernel/trace/bpf_trace.c:2406 #7: ffffc9001ba230d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20e/0x650 kernel/bpf/ringbuf.c:423 #8: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: trace_call_bpf+0xb9/0x8a0 kernel/trace/bpf_trace.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 52 Comm: kworker/1:1 Not tainted 6.14.0-syzkaller-g8582d9ab3efd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: wg-crypt-wg1 wg_packet_tx_worker Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x2be/0x2d0 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain+0x928/0x24e0 kernel/locking/lockdep.c:3896 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd8/0x130 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x20e/0x650 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:466 bpf_prog_ba4789e7f2e155d6+0x36/0x53 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] bpf_prog_run_array include/linux/bpf.h:2215 [inline] trace_call_bpf+0x36a/0x8a0 kernel/trace/bpf_trace.c:146 perf_trace_run_bpf_submit+0x82/0x180 kernel/events/core.c:10807 do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x39c/0x4a0 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x3b4/0x3e0 kernel/locking/lockdep.c:5877 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x7a/0x140 kernel/locking/spinlock.c:194 __bpf_ringbuf_reserve+0x4f8/0x650 kernel/bpf/ringbuf.c:449 ____bpf_ringbuf_output kernel/bpf/ringbuf.c:549 [inline] bpf_ringbuf_output+0x67/0x1e0 kernel/bpf/ringbuf.c:539 bpf_prog_918f90024333f9ff+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline] bpf_trace_run4+0x336/0x5a0 kernel/trace/bpf_trace.c:2406 __bpf_trace_net_dev_xmit+0x29f/0x3e0 include/trace/events/net.h:72 __traceiter_net_dev_xmit+0x8e/0xe0 include/trace/events/net.h:72 __do_trace_net_dev_xmit include/trace/events/net.h:72 [inline] trace_net_dev_xmit include/trace/events/net.h:72 [inline] xmit_one net/core/dev.c:3781 [inline] dev_hard_start_xmit+0x6ec/0x840 net/core/dev.c:3796 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4633 neigh_output include/net/neighbour.h:539 [inline] ip6_finish_output2+0x1296/0x1750 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x421/0x840 net/ipv6/ip6_output.c:226 ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline] udp_tunnel6_xmit_skb+0x620/0xa80 net/ipv6/ip6_udp_tunnel.c:111 send6+0x743/0xbf0 drivers/net/wireguard/socket.c:152 wg_socket_send_skb_to_peer+0x115/0x1d0 drivers/net/wireguard/socket.c:178 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline] wg_packet_tx_worker+0x1bf/0x810 drivers/net/wireguard/send.c:276 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245