===================================== WARNING: bad unlock balance detected! 5.5.0-rc5-syzkaller #0 Not tainted ------------------------------------- blkid/11607 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: 7 locks held by blkid/11607: #0: ffff888062c18598 (&mm->mmap_sem#2){++++}, at: setup_arg_pages+0x28a/0x7c0 fs/exec.c:741 #1: ffffc90000007d50 ((&ndev->rs_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:172 [inline] #1: ffffc90000007d50 ((&ndev->rs_timer)){+.-.}, at: call_timer_fn+0xe0/0x780 kernel/time/timer.c:1394 #2: ffffffff899a3f00 (rcu_read_lock){....}, at: ip6_nd_hdr net/ipv6/ndisc.c:463 [inline] #2: ffffffff899a3f00 (rcu_read_lock){....}, at: ndisc_send_skb+0x7fe/0x1490 net/ipv6/ndisc.c:499 #3: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #3: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x214/0x25c0 net/ipv6/ip6_output.c:102 #4: ffffffff899a3ec0 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35c0 net/core/dev.c:3948 #5: ffff88808d1ef250 (&dev->qdisc_tx_busylock_key#20){+...}, at: spin_trylock include/linux/spinlock.h:348 [inline] #5: ffff88808d1ef250 (&dev->qdisc_tx_busylock_key#20){+...}, at: qdisc_run_begin include/net/sch_generic.h:159 [inline] #5: ffff88808d1ef250 (&dev->qdisc_tx_busylock_key#20){+...}, at: __dev_xmit_skb net/core/dev.c:3611 [inline] #5: ffff88808d1ef250 (&dev->qdisc_tx_busylock_key#20){+...}, at: __dev_queue_xmit+0x2412/0x35c0 net/core/dev.c:3982 #6: ffff88808d1ef138 (&dev->qdisc_running_key#20){+...}, at: dev_queue_xmit+0x18/0x20 net/core/dev.c:4046 stack backtrace: CPU: 0 PID: 11607 Comm: blkid 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:rcu_read_lock_sched_held+0xf/0xd0 kernel/rcu/update.c:117 Code: 48 83 f0 01 83 e0 01 c3 0f 0b 48 c7 c7 d0 34 93 89 e8 35 81 51 00 eb d2 0f 1f 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 <48> 8d 5d 98 48 83 ec 60 48 c7 45 98 b3 8a b5 41 48 c7 45 a0 a0 9f RSP: 0018:ffffc900015878a0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff8880a6473630 RCX: 1ffffffff14f6f86 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888098b36e14 RBP: ffffc900015878a8 R08: 1ffffffff165e7ad R09: fffffbfff165e7ae R10: fffffbfff165e7ad R11: ffffffff8b2f3d6f R12: ffff8880aa412a80 R13: ffffffff81a377a8 R14: 0000000000000282 R15: ffffc90001587a38 trace_kmem_cache_free include/trace/events/kmem.h:145 [inline] kmem_cache_free+0x26b/0x320 mm/slab.c:3697 ptlock_free+0x38/0x42 mm/memory.c:4800 pgtable_pmd_page_dtor include/linux/mm.h:2009 [inline] ___pmd_free_tlb+0xb3/0x140 arch/x86/mm/pgtable.c:65 __pmd_free_tlb arch/x86/include/asm/pgalloc.h:118 [inline] free_pmd_range mm/memory.c:252 [inline] free_pud_range mm/memory.c:270 [inline] free_p4d_range mm/memory.c:304 [inline] free_pgd_range+0xaf0/0xd50 mm/memory.c:384 shift_arg_pages+0x29e/0x480 fs/exec.c:673 setup_arg_pages+0x639/0x7c0 fs/exec.c:766 load_elf_binary+0xbc4/0x5310 fs/binfmt_elf.c:864 search_binary_handler fs/exec.c:1658 [inline] search_binary_handler+0x16d/0x570 fs/exec.c:1635 exec_binprm fs/exec.c:1701 [inline] __do_execve_file.isra.0+0x1329/0x22b0 fs/exec.c:1821 do_execveat_common fs/exec.c:1867 [inline] do_execve fs/exec.c:1884 [inline] __do_sys_execve fs/exec.c:1960 [inline] __se_sys_execve fs/exec.c:1955 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1955 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff419b0e207 Code: Bad RIP value. RSP: 002b:00007ffea9658b28 EFLAGS: 00000206 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007ff419b0e207 RDX: 0000000000ed0ab0 RSI: 00007ffea9658c20 RDI: 00007ffea9659c30 RBP: 0000000000625500 R08: 00000000000028e8 R09: 00000000000028e8 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000ed0ab0 R13: 0000000000000007 R14: 0000000000ecf250 R15: 0000000000000005