============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- kworker/u8:7/1127 is trying to acquire lock: ffff88807c4bb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] ffff88807c4bb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4809 [inline] ffff88807c4bb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 but task is already holding lock: ffff8880203ac158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] ffff8880203ac158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4809 [inline] ffff8880203ac158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qdisc_xmit_lock_key#4); lock(&qdisc_xmit_lock_key#4); *** DEADLOCK *** May be due to missing lock nesting notation 11 locks held by kworker/u8:7/1127: #0: ffff8880547dd940 ((wq_completion)bond13){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880547dd940 ((wq_completion)bond13){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90005707c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90005707c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #2: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: bond_alb_monitor+0xf3/0x17c0 drivers/net/bonding/bond_alb.c:1546 #3: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:893 [inline] #3: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x37f0 net/core/dev.c:4796 #4: ffff88807ba68228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:354 [inline] #4: ffff88807ba68228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:205 [inline] #4: ffff88807ba68228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4201 [inline] #4: ffff88807ba68228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x112b/0x37f0 net/core/dev.c:4836 #5: ffff8880203ac158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] #5: ffff8880203ac158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4809 [inline] #5: ffff8880203ac158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 #6: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #6: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #6: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3de/0x10b0 net/ipv4/ip_output.c:229 #7: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #7: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:893 [inline] #7: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x37f0 net/core/dev.c:4796 #8: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #8: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #8: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x19d/0x1a30 net/bridge/br_device.c:52 #9: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:893 [inline] #9: ffffffff8eb59c80 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x37f0 net/core/dev.c:4796 #10: ffff88807cd94228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:354 [inline] #10: ffff88807cd94228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:205 [inline] #10: ffff88807cd94228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4201 [inline] #10: ffff88807cd94228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x112b/0x37f0 net/core/dev.c:4836 stack backtrace: CPU: 0 UID: 0 PID: 1127 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: bond13 bond_alb_monitor Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x24df/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] __netif_tx_lock include/linux/netdevice.h:4809 [inline] sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 __dev_xmit_skb net/core/dev.c:4214 [inline] __dev_queue_xmit+0x1754/0x37f0 net/core/dev.c:4836 dev_queue_xmit include/linux/netdevice.h:3446 [inline] br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:325 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:325 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 br_dev_xmit+0xb62/0x1a30 net/bridge/br_device.c:92 __netdev_start_xmit include/linux/netdevice.h:5400 [inline] netdev_start_xmit include/linux/netdevice.h:5409 [inline] xmit_one net/core/dev.c:3892 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3908 __dev_queue_xmit+0x1435/0x37f0 net/core/dev.c:4875 neigh_output include/net/neighbour.h:560 [inline] ip_finish_output2+0xc4b/0x10b0 net/ipv4/ip_output.c:236 iptunnel_xmit+0x626/0xd10 net/ipv4/ip_tunnel_core.c:97 ip_tunnel_xmit+0x195b/0x2040 net/ipv4/ip_tunnel.c:848 __gre_xmit+0x19e/0x240 net/ipv4/ip_gre.c:491 erspan_xmit+0xad5/0x1590 net/ipv4/ip_gre.c:750 __netdev_start_xmit include/linux/netdevice.h:5400 [inline] netdev_start_xmit include/linux/netdevice.h:5409 [inline] xmit_one net/core/dev.c:3892 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3908 sch_direct_xmit+0x257/0x4c0 net/sched/sch_generic.c:372 __dev_xmit_skb net/core/dev.c:4214 [inline] __dev_queue_xmit+0x1754/0x37f0 net/core/dev.c:4836 dev_queue_xmit include/linux/netdevice.h:3446 [inline] alb_send_lp_vid+0x348/0x550 drivers/net/bonding/bond_alb.c:949 alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1012 bond_alb_monitor+0x3d0/0x17c0 drivers/net/bonding/bond_alb.c:1563 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 bond0: (slave bond_slave_0): link status definitely up, 10000 Mbps full duplex bond0: (slave bond_slave_1): link status definitely up, 10000 Mbps full duplex bond0: active interface up!