============================================ WARNING: possible recursive locking detected 5.15.179-syzkaller #0 Not tainted -------------------------------------------- kworker/u4:18/7790 is trying to acquire lock: ffff888076896218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline] ffff888076896218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3908 [inline] ffff888076896218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_queue_xmit+0x2158/0x32b0 net/core/dev.c:4252 but task is already holding lock: ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline] ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:173 [inline] ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3870 [inline] ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1178/0x32b0 net/core/dev.c:4252 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/u4:18/7790: #0: ffff8880749f2938 ((wq_completion)bond1){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000321fd20 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8cb1f4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #3: ffffffff8cb1f540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:312 #4: ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline] #4: ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:173 [inline] #4: ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3870 [inline] #4: ffff88801ff57258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1178/0x32b0 net/core/dev.c:4252 #5: ffffffff8cb1f540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:312 #6: ffffffff8cb1f540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:312 stack backtrace: CPU: 1 PID: 7790 Comm: kworker/u4:18 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bond1 bond_alb_monitor Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2946 [inline] check_deadlock kernel/locking/lockdep.c:2989 [inline] validate_chain+0x46d2/0x5930 kernel/locking/lockdep.c:3775 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] __dev_xmit_skb net/core/dev.c:3908 [inline] __dev_queue_xmit+0x2158/0x32b0 net/core/dev.c:4252 neigh_hh_output include/net/neighbour.h:493 [inline] neigh_output include/net/neighbour.h:507 [inline] ip_finish_output2+0xcd7/0x11a0 net/ipv4/ip_output.c:228 iptunnel_xmit+0x51a/0x950 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x19c9/0x24f0 net/ipv4/ip_tunnel.c:838 __gre_xmit net/ipv4/ip_gre.c:474 [inline] gre_tap_xmit+0x4f8/0x6e0 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:3648 [inline] dev_hard_start_xmit+0x298/0x7a0 net/core/dev.c:3664 sch_direct_xmit+0x2b2/0x5e0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3883 [inline] __dev_queue_xmit+0x1861/0x32b0 net/core/dev.c:4252 alb_send_learning_packets+0x197/0x340 drivers/net/bonding/bond_alb.c:1000 bond_alb_monitor+0x3c8/0x16f0 drivers/net/bonding/bond_alb.c:1528 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287