============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- kworker/u8:24/9595 is trying to acquire lock: ffff88805ef50218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88805ef50218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4148 [inline] ffff88805ef50218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_queue_xmit+0x22b7/0x3b50 net/core/dev.c:4691 but task is already holding lock: ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline] ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:197 [inline] ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4101 [inline] ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_queue_xmit+0x138a/0x3b50 net/core/dev.c:4691 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3); lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3); *** DEADLOCK *** May be due to missing lock nesting notation 8 locks held by kworker/u8:24/9595: #0: ffff88807f48c948 ((wq_completion)bond3#4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88807f48c948 ((wq_completion)bond3#4){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000b52fbc0 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000b52fbc0 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: bond_alb_monitor+0xf1/0x1800 drivers/net/bonding/bond_alb.c:1546 #3: ffffffff8e13a140 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8e13a140 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #3: ffffffff8e13a140 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4650 #4: ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline] #4: ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:197 [inline] #4: ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4101 [inline] #4: ffff88805f736258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_queue_xmit+0x138a/0x3b50 net/core/dev.c:4691 #5: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #5: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:432 #6: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #6: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #6: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x452/0x1160 net/ipv4/ip_output.c:229 #7: ffffffff8e13a140 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #7: ffffffff8e13a140 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #7: ffffffff8e13a140 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4650 stack backtrace: CPU: 1 UID: 0 PID: 9595 Comm: kworker/u8:24 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bond3 bond_alb_monitor Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __dev_xmit_skb net/core/dev.c:4148 [inline] __dev_queue_xmit+0x22b7/0x3b50 net/core/dev.c:4691 neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0xd3d/0x1160 net/ipv4/ip_output.c:236 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:437 iptunnel_xmit+0x5f8/0xa90 net/ipv4/ip_tunnel_core.c:84 ip_tunnel_xmit+0x1c41/0x2390 net/ipv4/ip_tunnel.c:859 __gre_xmit net/ipv4/ip_gre.c:488 [inline] gre_tap_xmit+0x590/0x7a0 net/ipv4/ip_gre.c:776 __netdev_start_xmit include/linux/netdevice.h:5222 [inline] netdev_start_xmit include/linux/netdevice.h:5231 [inline] xmit_one net/core/dev.c:3839 [inline] dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3855 sch_direct_xmit+0x241/0x4b0 net/sched/sch_generic.c:344 __dev_xmit_skb net/core/dev.c:4114 [inline] __dev_queue_xmit+0x1857/0x3b50 net/core/dev.c:4691 dev_queue_xmit include/linux/netdevice.h:3361 [inline] alb_send_lp_vid+0x324/0x510 drivers/net/bonding/bond_alb.c:949 alb_send_learning_packets+0x10d/0x2c0 drivers/net/bonding/bond_alb.c:1012 bond_alb_monitor+0x3e4/0x1800 drivers/net/bonding/bond_alb.c:1563 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245