===================================== WARNING: bad unlock balance detected! 5.5.0-rc5-syzkaller #0 Not tainted ------------------------------------- syz-executor.0/16221 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:3969 [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.0/16221: #0: ffffc90000007d50 ((&n->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:172 [inline] #0: ffffc90000007d50 ((&n->timer)){+.-.}, at: call_timer_fn+0xe0/0x780 kernel/time/timer.c:1394 #1: ffffffff899a3f40 (rcu_read_lock){....}, at: ip6_nd_hdr net/ipv6/ndisc.c:463 [inline] #1: ffffffff899a3f40 (rcu_read_lock){....}, at: ndisc_send_skb+0x7fe/0x1490 net/ipv6/ndisc.c:499 #2: ffffffff899a3f00 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #2: ffffffff899a3f00 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x214/0x25c0 net/ipv6/ip6_output.c:102 #3: ffffffff899a3f00 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35c0 net/core/dev.c:3948 #4: ffff88808e464250 (&dev->qdisc_tx_busylock_key#15){+...}, at: spin_trylock include/linux/spinlock.h:348 [inline] #4: ffff88808e464250 (&dev->qdisc_tx_busylock_key#15){+...}, at: qdisc_run_begin include/net/sch_generic.h:159 [inline] #4: ffff88808e464250 (&dev->qdisc_tx_busylock_key#15){+...}, at: __dev_xmit_skb net/core/dev.c:3611 [inline] #4: ffff88808e464250 (&dev->qdisc_tx_busylock_key#15){+...}, at: __dev_queue_xmit+0x2412/0x35c0 net/core/dev.c:3982 #5: ffff88808e464138 (&dev->qdisc_running_key#15){+...}, at: dev_queue_xmit+0x18/0x20 net/core/dev.c:4046 stack backtrace: CPU: 0 PID: 16221 Comm: syz-executor.0 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:3969 [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_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0xfbe/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_ns+0x3a9/0x850 net/ipv6/ndisc.c:647 ndisc_solicit+0x2ed/0x470 net/ipv6/ndisc.c:739 neigh_probe+0xd0/0x120 net/core/neighbour.c:1009 neigh_timer_handler+0x59d/0x10e0 net/core/neighbour.c:1090 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 af 92 ba 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 01 f3 77 f9 65 8b 05 42 7c 29 78 RSP: 0018:ffffc90001747400 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff132669b RBX: 0000000000000282 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: 0000000000000282 RBP: ffffc90001747410 R08: ffff8880612d84c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8b8e0988 R13: ffffffff8b8e0988 R14: ffff888058e06000 R15: 0000000000000003 __debug_check_no_obj_freed lib/debugobjects.c:973 [inline] debug_check_no_obj_freed+0x20a/0x43f lib/debugobjects.c:994 free_pages_prepare mm/page_alloc.c:1175 [inline] __free_pages_ok+0x266/0xea0 mm/page_alloc.c:1427 free_compound_page+0x97/0xd0 mm/page_alloc.c:674 free_transhuge_page+0x2a7/0x3b0 mm/huge_memory.c:2847 __put_compound_page+0x90/0xd0 mm/swap.c:97 release_pages+0x666/0x1bd0 mm/swap.c:829 free_pages_and_swap_cache+0x2c3/0x3f0 mm/swap_state.c:296 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:184 [inline] tlb_flush_mmu+0x89/0x630 mm/mmu_gather.c:191 zap_pte_range mm/memory.c:1146 [inline] zap_pmd_range mm/memory.c:1184 [inline] zap_pud_range mm/memory.c:1213 [inline] zap_p4d_range mm/memory.c:1234 [inline] unmap_page_range+0x1ba1/0x28a0 mm/memory.c:1255 unmap_single_vma+0x19d/0x300 mm/memory.c:1300 unmap_vmas+0x184/0x2f0 mm/memory.c:1332 exit_mmap+0x2ba/0x530 mm/mmap.c:3134 __mmput kernel/fork.c:1082 [inline] mmput+0x179/0x4d0 kernel/fork.c:1103 exit_mm kernel/exit.c:485 [inline] do_exit+0xac2/0x2f50 kernel/exit.c:788 do_group_exit+0x135/0x360 kernel/exit.c:899 get_signal+0x47c/0x24f0 kernel/signal.c:2734 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f94efcc0cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 000000000075bf28 RCX: 000000000045af49 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000075bf2c RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf2c R13: 00007fff6ae6008f R14: 00007f94efcc19c0 R15: 000000000075bf2c 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. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.