===================================== WARNING: bad unlock balance detected! 5.5.0-rc6-syzkaller #0 Not tainted ------------------------------------- kworker/u4:0/7 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: 10 locks held by kworker/u4:0/7: #0: ffff8880a6f24128 ((wq_completion)bat_events){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a6f24128 ((wq_completion)bat_events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a6f24128 ((wq_completion)bat_events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a6f24128 ((wq_completion)bat_events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a6f24128 ((wq_completion)bat_events){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a6f24128 ((wq_completion)bat_events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a6f24128 ((wq_completion)bat_events){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2235 #1: ffffc90000cdfdc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239 #2: ffffffff899a3f00 (rcu_read_lock){....}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:405 [inline] #2: ffffffff899a3f00 (rcu_read_lock){....}, at: batadv_nc_worker+0xe3/0x760 net/batman-adv/network-coding.c:718 #3: ffffc90000da8d50 ((&icsk->icsk_retransmit_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:172 [inline] #3: ffffc90000da8d50 ((&icsk->icsk_retransmit_timer)){+.-.}, at: call_timer_fn+0xe0/0x780 kernel/time/timer.c:1394 #4: ffff888059f26b60 (slock-AF_INET6){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] #4: ffff888059f26b60 (slock-AF_INET6){+.-.}, at: dccp_write_timer+0x2f/0x1480 net/dccp/timer.c:131 #5: ffffffff899a3f00 (rcu_read_lock){....}, at: sock_net include/net/sock.h:2474 [inline] #5: ffffffff899a3f00 (rcu_read_lock){....}, at: __ip_queue_xmit+0x42/0x1c10 net/ipv4/ip_output.c:457 #6: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #6: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2610 net/ipv4/ip_output.c:214 #7: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35c0 net/core/dev.c:3948 #8: ffff8880a3eec250 (&dev->qdisc_tx_busylock_key#21){+...}, at: spin_trylock include/linux/spinlock.h:348 [inline] #8: ffff8880a3eec250 (&dev->qdisc_tx_busylock_key#21){+...}, at: qdisc_run_begin include/net/sch_generic.h:159 [inline] #8: ffff8880a3eec250 (&dev->qdisc_tx_busylock_key#21){+...}, at: __dev_xmit_skb net/core/dev.c:3611 [inline] #8: ffff8880a3eec250 (&dev->qdisc_tx_busylock_key#21){+...}, at: __dev_queue_xmit+0x2412/0x35c0 net/core/dev.c:3982 #9: ffff8880a3eec138 (&dev->qdisc_running_key#21){+...}, at: dev_queue_xmit+0x18/0x20 net/core/dev.c:4046 stack backtrace: CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.5.0-rc6-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 arp_xmit_finish net/ipv4/arp.c:630 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] arp_xmit+0xdf/0x3f0 net/ipv4/arp.c:639 arp_send_dst.part.0+0x202/0x290 net/ipv4/arp.c:317 arp_send_dst net/ipv4/arp.c:390 [inline] arp_solicit+0x748/0x1370 net/ipv4/arp.c:389 neigh_probe+0xd0/0x120 net/core/neighbour.c:1009 __neigh_event_send+0x3e3/0x17c0 net/core/neighbour.c:1169 neigh_event_send include/net/neighbour.h:444 [inline] neigh_resolve_output+0x5ee/0x990 net/core/neighbour.c:1471 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x909/0x2610 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x604/0xbd0 net/ipv4/ip_output.c:290 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x22b/0x680 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0xbb/0x1b0 net/ipv4/ip_output.c:125 __ip_queue_xmit+0x86f/0x1c10 net/ipv4/ip_output.c:532 ip_queue_xmit+0x5a/0x70 include/net/ip.h:237 dccp_transmit_skb+0x966/0x12a0 net/dccp/output.c:138 dccp_retransmit_skb+0x118/0x170 net/dccp/output.c:387 dccp_retransmit_timer net/dccp/timer.c:101 [inline] dccp_write_timer+0x48a/0x1480 net/dccp/timer.c:153 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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:lock_acquire+0x20b/0x410 kernel/locking/lockdep.c:4488 Code: 94 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 d3 01 00 00 48 83 3d f9 5a 38 08 00 0f 84 53 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65 8b RSP: 0018:ffffc90000cdfc80 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff132669b RBX: ffff8880a99a81c0 RCX: ffffffff815a7ef0 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282 RBP: ffffc90000cdfcc8 R08: 1ffffffff165e79c R09: fffffbfff165e79d R10: ffff8880a99a8aa8 R11: ffff8880a99a81c0 R12: ffffffff899a3f00 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:617 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0x117/0x760 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