============================================ WARNING: possible recursive locking detected syzkaller #0 Tainted: G L -------------------------------------------- kworker/u32:3/59 is trying to acquire lock: ffff888013bcf158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] ffff888013bcf158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] ffff888013bcf158 (&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: ffff888013446158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] ffff888013446158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] ffff888013446158 (&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/u32:3/59: #0: ffff88806a39c148 ((wq_completion)bond2){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250 #1: ffffc900007afd08 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251 #2: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #2: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #2: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: bond_alb_monitor+0xec/0x1700 drivers/net/bonding/bond_alb.c:1546 #3: ffffffff8e7e91c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8e7e91c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #3: ffffffff8e7e91c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x4750 net/core/dev.c:4761 #4: ffff8880640df228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:353 [inline] #4: ffff8880640df228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #4: ffff8880640df228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4173 [inline] #4: ffff8880640df228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_queue_xmit+0x226a/0x4750 net/core/dev.c:4802 #5: ffff888013446158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #5: ffff888013446158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] #5: ffff888013446158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3b5/0xc60 net/sched/sch_generic.c:345 #6: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #6: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #6: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: ip_output+0xb3/0xec0 net/ipv4/ip_output.c:433 #7: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #7: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #7: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x356/0x24d0 net/ipv4/ip_output.c:230 #8: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #8: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #8: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x26/0x2e0 net/ipv4/arp.c:664 #9: ffffffff8e7e91c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8e7e91c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #9: ffffffff8e7e91c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x4750 net/core/dev.c:4761 #10: ffff88802ad27228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:353 [inline] #10: ffff88802ad27228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #10: ffff88802ad27228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4173 [inline] #10: ffff88802ad27228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_queue_xmit+0x226a/0x4750 net/core/dev.c:4802 stack backtrace: CPU: 3 UID: 0 PID: 59 Comm: kworker/u32:3 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: bond2 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+0x1cf/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:341 [inline] __netif_tx_lock include/linux/netdevice.h:4713 [inline] sch_direct_xmit+0x3b5/0xc60 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:4186 [inline] __dev_queue_xmit+0x250e/0x4750 net/core/dev.c:4802 dev_queue_xmit include/linux/netdevice.h:3384 [inline] arp_xmit_finish net/ipv4/arp.c:656 [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:666 arp_send_dst net/ipv4/arp.c:321 [inline] arp_send_dst+0x200/0x280 net/ipv4/arp.c:302 arp_solicit+0x672/0x1070 net/ipv4/arp.c:393 neigh_probe+0xce/0x110 net/core/neighbour.c:1096 __neigh_event_send+0xae9/0x1430 net/core/neighbour.c:1276 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:1603 neigh_output include/net/neighbour.h:556 [inline] ip_finish_output2+0x851/0x24d0 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:470 [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+0x1b85/0x3200 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:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3871 [inline] dev_hard_start_xmit+0x121/0x7d0 net/core/dev.c:3887 sch_direct_xmit+0x1b2/0xc60 net/sched/sch_generic.c:347 __dev_xmit_skb net/core/dev.c:4186 [inline] __dev_queue_xmit+0x250e/0x4750 net/core/dev.c:4802 dev_queue_xmit include/linux/netdevice.h:3384 [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+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245