===================================== WARNING: bad unlock balance detected! 5.5.0-rc5-syzkaller #0 Not tainted ------------------------------------- syz-executor.5/9551 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: 6 locks held by syz-executor.5/9551: #0: ffffc90000007d50 ((&ndev->rs_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:172 [inline] #0: ffffc90000007d50 ((&ndev->rs_timer)){+.-.}, at: call_timer_fn+0xe0/0x780 kernel/time/timer.c:1394 #1: ffffffff899a3f00 (rcu_read_lock){....}, at: ip6_nd_hdr net/ipv6/ndisc.c:463 [inline] #1: ffffffff899a3f00 (rcu_read_lock){....}, at: ndisc_send_skb+0x7fe/0x1490 net/ipv6/ndisc.c:499 #2: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #2: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x214/0x25c0 net/ipv6/ip6_output.c:102 #3: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35c0 net/core/dev.c:3948 #4: ffff8880a8f3d250 (&dev->qdisc_tx_busylock_key#23){+...}, at: spin_trylock include/linux/spinlock.h:348 [inline] #4: ffff8880a8f3d250 (&dev->qdisc_tx_busylock_key#23){+...}, at: qdisc_run_begin include/net/sch_generic.h:159 [inline] #4: ffff8880a8f3d250 (&dev->qdisc_tx_busylock_key#23){+...}, at: __dev_xmit_skb net/core/dev.c:3611 [inline] #4: ffff8880a8f3d250 (&dev->qdisc_tx_busylock_key#23){+...}, at: __dev_queue_xmit+0x2412/0x35c0 net/core/dev.c:3982 #5: ffff8880a8f3d138 (&dev->qdisc_running_key#23){+...}, at: dev_queue_xmit+0x18/0x20 net/core/dev.c:4046 stack backtrace: CPU: 0 PID: 9551 Comm: syz-executor.5 Not tainted 5.5.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x90/0xe0 kernel/locking/spinlock.c:191 Code: 48 c7 c0 d8 34 93 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d ef ef be 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 91 45 7c f9 65 8b 05 82 d9 2d 78 RSP: 0018:ffffc900029e7b78 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff132669b RBX: 0000000000000282 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: 0000000000000282 RBP: ffffc900029e7b88 R08: ffff888062f76600 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a9a48120 R13: ffff8880a9a48158 R14: 0000000000000282 R15: ffffc900029e7cf8 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] add_wait_queue+0x112/0x170 kernel/sched/wait.c:25 do_wait+0x19f/0xa10 kernel/exit.c:1428 kernel_wait4+0x171/0x290 kernel/exit.c:1617 __do_sys_wait4+0x147/0x160 kernel/exit.c:1629 __se_sys_wait4 kernel/exit.c:1625 [inline] __x64_sys_wait4+0x97/0xf0 kernel/exit.c:1625 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414d8a Code: 0f 83 6a 18 00 00 c3 66 0f 1f 84 00 00 00 00 00 8b 05 ee 36 66 00 85 c0 75 36 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 d4 ff ff ff f7 RSP: 002b:00007ffd70211468 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 000000000006b5c1 RCX: 0000000000414d8a RDX: 0000000040000001 RSI: 00007ffd702114a0 RDI: ffffffffffffffff RBP: 0000000000000512 R08: 0000000000000001 R09: 0000000000e92940 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000f R13: 00007ffd702114a0 R14: 000000000006b358 R15: 00007ffd702114b0