============================================ WARNING: possible recursive locking detected syzkaller #0 Tainted: G L -------------------------------------------- kworker/u32:8/1154 is trying to acquire lock: ffff8880311fad58 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880311fad58 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4710 [inline] ffff8880311fad58 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3b5/0xc60 net/sched/sch_generic.c:345 but task is already holding lock: ffff888029735958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff888029735958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4710 [inline] ffff888029735958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3b5/0xc60 net/sched/sch_generic.c:345 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/u32:8/1154: #0: ffff888058915948 ((wq_completion)bond1#3){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc900061e7c98 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #2: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: bond_alb_monitor+0xec/0x1700 drivers/net/bonding/bond_alb.c:1546 #3: ffffffff8e5e3280 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8e5e3280 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #3: ffffffff8e5e3280 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x46f0 net/core/dev.c:4757 #4: ffff888026092228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline] #4: ffff888026092228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #4: ffff888026092228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4169 [inline] #4: ffff888026092228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x2219/0x46f0 net/core/dev.c:4798 #5: ffff888029735958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #5: ffff888029735958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4710 [inline] #5: ffff888029735958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3b5/0xc60 net/sched/sch_generic.c:345 #6: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #6: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #6: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: ip_output+0xb3/0xec0 net/ipv4/ip_output.c:433 #7: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #7: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x356/0x24b0 net/ipv4/ip_output.c:230 #8: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #8: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #8: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x26/0x2e0 net/ipv4/arp.c:663 #9: ffffffff8e5e3280 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8e5e3280 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #9: ffffffff8e5e3280 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x46f0 net/core/dev.c:4757 #10: ffff88805b410228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline] #10: ffff88805b410228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #10: ffff88805b410228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4169 [inline] #10: ffff88805b410228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x2219/0x46f0 net/core/dev.c:4798 stack backtrace: CPU: 2 UID: 0 PID: 1154 Comm: kworker/u32:8 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: bond1 bond_alb_monitor Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_deadlock_bug.cold+0xbd/0xca kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x12bb/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825 __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] __netif_tx_lock include/linux/netdevice.h:4710 [inline] sch_direct_xmit+0x3b5/0xc60 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:4182 [inline] __dev_queue_xmit+0x24bd/0x46f0 net/core/dev.c:4798 dev_queue_xmit include/linux/netdevice.h:3381 [inline] arp_xmit_finish net/ipv4/arp.c:655 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] arp_xmit+0x106/0x2e0 net/ipv4/arp.c:665 arp_send_dst net/ipv4/arp.c:320 [inline] arp_send_dst+0x200/0x280 net/ipv4/arp.c:301 arp_solicit+0x672/0x1070 net/ipv4/arp.c:392 neigh_probe+0xce/0x110 net/core/neighbour.c:1097 __neigh_event_send+0xa98/0x1360 net/core/neighbour.c:1270 neigh_event_send_probe include/net/neighbour.h:480 [inline] neigh_event_send include/net/neighbour.h:486 [inline] neigh_event_send include/net/neighbour.h:484 [inline] neigh_resolve_output+0x550/0x8f0 net/core/neighbour.c:1578 neigh_output include/net/neighbour.h:556 [inline] ip_finish_output2+0x851/0x24b0 net/ipv4/ip_output.c:237 __ip_finish_output.part.0+0x444/0x6f0 net/ipv4/ip_output.c:315 __ip_finish_output net/ipv4/ip_output.c:303 [inline] ip_finish_output net/ipv4/ip_output.c:325 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x39b/0xec0 net/ipv4/ip_output.c:438 dst_output include/net/dst.h:464 [inline] ip_local_out+0x35b/0x4a0 net/ipv4/ip_output.c:131 iptunnel_xmit+0x6d2/0xac0 net/ipv4/ip_tunnel_core.c:84 ip_tunnel_xmit+0x1dfa/0x3740 net/ipv4/ip_tunnel.c:845 __gre_xmit+0x820/0xb20 net/ipv4/ip_gre.c:490 erspan_xmit+0x55a/0x1ec0 net/ipv4/ip_gre.c:749 __netdev_start_xmit include/linux/netdevice.h:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3866 [inline] dev_hard_start_xmit+0x127/0x6c0 net/core/dev.c:3882 sch_direct_xmit+0x1b2/0xc60 net/sched/sch_generic.c:347 __dev_xmit_skb net/core/dev.c:4182 [inline] __dev_queue_xmit+0x24bd/0x46f0 net/core/dev.c:4798 dev_queue_xmit include/linux/netdevice.h:3381 [inline] alb_send_lp_vid+0x31e/0x540 drivers/net/bonding/bond_alb.c:949 alb_send_learning_packets+0xe0/0x2f0 drivers/net/bonding/bond_alb.c:1012 bond_alb_monitor+0x9a0/0x1700 drivers/net/bonding/bond_alb.c:1563 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246