============================================ WARNING: possible recursive locking detected 5.15.184-syzkaller #0 Not tainted -------------------------------------------- kworker/u4:7/4107 is trying to acquire lock: ffff0000d5c98218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline] ffff0000d5c98218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3909 [inline] ffff0000d5c98218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_queue_xmit+0x18c8/0x2800 net/core/dev.c:4253 but task is already holding lock: ffff0000c2807258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline] ffff0000c2807258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: qdisc_run_begin+0x120/0x2a8 include/net/sch_generic.h:173 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by kworker/u4:7/4107: #0: ffff0000d1f65138 ((wq_completion)bond2){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001f767c00 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff8000143211e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311 #3: ffff800014321240 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 #4: ffff0000c2807258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline] #4: ffff0000c2807258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: qdisc_run_begin+0x120/0x2a8 include/net/sch_generic.h:173 #5: ffff800014321240 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 #6: ffff800014321240 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 4107 Comm: kworker/u4:7 Not tainted 5.15.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bond2 bond_alb_monitor Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 __lock_acquire+0x18a4/0x651c kernel/locking/lockdep.c:-1 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0xb0/0x10c kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] __dev_xmit_skb net/core/dev.c:3909 [inline] __dev_queue_xmit+0x18c8/0x2800 net/core/dev.c:4253 dev_queue_xmit+0x24/0x34 net/core/dev.c:4321 neigh_hh_output include/net/neighbour.h:493 [inline] neigh_output include/net/neighbour.h:507 [inline] ip_finish_output2+0xdac/0x1228 net/ipv4/ip_output.c:228 __ip_finish_output+0x1b0/0x448 net/ipv4/ip_output.c:-1 ip_finish_output+0x40/0x218 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_output+0x314/0x414 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:452 [inline] ip_local_out+0x120/0x15c net/ipv4/ip_output.c:126 iptunnel_xmit+0x3f8/0x8dc net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x181c/0x1f30 net/ipv4/ip_tunnel.c:838 __gre_xmit net/ipv4/ip_gre.c:474 [inline] gre_tap_xmit+0x3f8/0x5e4 net/ipv4/ip_gre.c:751 __netdev_start_xmit include/linux/netdevice.h:5027 [inline] netdev_start_xmit include/linux/netdevice.h:5041 [inline] xmit_one net/core/dev.c:3649 [inline] dev_hard_start_xmit+0x2a8/0x87c net/core/dev.c:3665 sch_direct_xmit+0x2a4/0x3bc net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3884 [inline] __dev_queue_xmit+0x13f4/0x2800 net/core/dev.c:4253 dev_queue_xmit+0x24/0x34 net/core/dev.c:4321 alb_send_lp_vid+0x2b4/0x5fc drivers/net/bonding/bond_alb.c:937 alb_send_learning_packets+0xf8/0x294 drivers/net/bonding/bond_alb.c:1000 bond_alb_monitor+0x2f4/0x121c drivers/net/bonding/bond_alb.c:1528 process_one_work+0x79c/0x1140 kernel/workqueue.c:2310 worker_thread+0x8f4/0x101c kernel/workqueue.c:2457 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870