GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog ===================================== WARNING: bad unlock balance detected! 5.5.0-rc5-syzkaller #0 Not tainted ------------------------------------- kworker/u4:6/929 is trying to release lock (&dev->qdisc_xmit_lock_key) at: [] spin_unlock include/linux/spinlock.h:378 [inline] [] __netif_tx_unlock include/linux/netdevice.h:3966 [inline] [] sch_direct_xmit+0x3fa/0xd30 net/sched/sch_generic.c:315 but there are no more locks to release! other info that might help us debug this: 8 locks held by kworker/u4:6/929: #0: ffff88821520c128 ((wq_completion)bat_events){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff88821520c128 ((wq_completion)bat_events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88821520c128 ((wq_completion)bat_events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff88821520c128 ((wq_completion)bat_events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff88821520c128 ((wq_completion)bat_events){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88821520c128 ((wq_completion)bat_events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88821520c128 ((wq_completion)bat_events){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2235 #1: ffffc900040c7dc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239 #2: ffffc90000007d50 ((&ndev->rs_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:172 [inline] #2: ffffc90000007d50 ((&ndev->rs_timer)){+.-.}, at: call_timer_fn+0xe0/0x780 kernel/time/timer.c:1394 #3: ffffffff899a3f00 (rcu_read_lock){....}, at: ip6_nd_hdr net/ipv6/ndisc.c:463 [inline] #3: ffffffff899a3f00 (rcu_read_lock){....}, at: ndisc_send_skb+0x7fe/0x1490 net/ipv6/ndisc.c:499 #4: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #4: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x214/0x25c0 net/ipv6/ip6_output.c:102 #5: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35c0 net/core/dev.c:3948 #6: ffff88809882e250 (&dev->qdisc_tx_busylock_key#25){+...}, at: spin_trylock include/linux/spinlock.h:348 [inline] #6: ffff88809882e250 (&dev->qdisc_tx_busylock_key#25){+...}, at: qdisc_run_begin include/net/sch_generic.h:159 [inline] #6: ffff88809882e250 (&dev->qdisc_tx_busylock_key#25){+...}, at: __dev_xmit_skb net/core/dev.c:3611 [inline] #6: ffff88809882e250 (&dev->qdisc_tx_busylock_key#25){+...}, at: __dev_queue_xmit+0x2412/0x35c0 net/core/dev.c:3982 #7: ffff88809882e138 (&dev->qdisc_running_key#25){+...}, at: dev_queue_xmit+0x18/0x20 net/core/dev.c:4046 stack backtrace: CPU: 0 PID: 929 Comm: kworker/u4:6 Not tainted 5.5.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_unlock_imbalance_bug kernel/locking/lockdep.c:4008 [inline] print_unlock_imbalance_bug.cold+0x114/0x123 kernel/locking/lockdep.c:3984 __lock_release kernel/locking/lockdep.c:4242 [inline] lock_release+0x5f2/0x960 kernel/locking/lockdep.c:4503 __raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock+0x16/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:378 [inline] __netif_tx_unlock include/linux/netdevice.h:3966 [inline] sch_direct_xmit+0x3fa/0xd30 net/sched/sch_generic.c:315 __dev_xmit_skb net/core/dev.c:3621 [inline] __dev_queue_xmit+0x2707/0x35c0 net/core/dev.c:3982 dev_queue_xmit+0x18/0x20 net/core/dev.c:4046 neigh_resolve_output net/core/neighbour.c:1487 [inline] neigh_resolve_output+0x5c4/0x990 net/core/neighbour.c:1467 neigh_output include/net/neighbour.h:510 [inline] ip6_finish_output2+0x109a/0x25c0 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x444/0xaa0 net/ipv6/ip6_output.c:142 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x25e/0x880 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xf1f/0x1490 net/ipv6/ndisc.c:505 ndisc_send_rs+0x134/0x720 net/ipv6/ndisc.c:699 addrconf_rs_timer+0x30f/0x6e0 net/ipv6/addrconf.c:3879 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__rcu_read_lock+0x70/0x90 kernel/rcu/tree_plugin.h:360 Code: 1c 25 c0 1e 02 00 48 8d bb 78 03 00 00 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 14 81 bb 78 03 00 00 ff ff ff 3f <7f> 03 5b 5d c3 0f 0b 5b 5d c3 e8 c1 06 51 00 eb e5 e8 ba 06 51 00 RSP: 0018:ffffc900040c7cc8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: ffff8880a7f9c580 RCX: ffffffff87b63892 RDX: 1ffff11014ff391f RSI: ffffffff87b63726 RDI: ffff8880a7f9c8f8 RBP: ffffc900040c7cd0 R08: ffff8880a7f9c580 R09: ffff8880a7f9ce10 R10: fffffbfff14f6948 R11: ffffffff8a7b4a47 R12: 0000000000000001 R13: 0000000000000123 R14: ffff888073f10918 R15: dffffc0000000000 rcu_read_lock include/linux/rcupdate.h:615 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0xf2/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.