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WARNING: bad unlock balance in __dev_queue_xmit

Status: closed as dup on 2020/01/11 23:38
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+ad4ea1dd5d26131a58a6@syzkaller.appspotmail.com
First crash: 1783d, last: 1775d
Cause bisection: introduced by (bisect log) :
commit ab92d68fc22f9afab480153bd82a20f6e2533769
Author: Taehee Yoo <ap420073@gmail.com>
Date: Mon Oct 21 18:47:51 2019 +0000

  net: core: add generic lockdep keys

Crash: BUG: MAX_LOCKDEP_KEYS too low! (log)
Repro: syz .config
  
▶ ▼ Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
WARNING: bad unlock balance in sch_direct_xmit net C done 35 1771d 1818d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
WARNING: bad unlock balance in __dev_queue_xmit 1 (3) 2020/01/11 23:38

Sample crash report:
=====================================
WARNING: bad unlock balance detected!
5.5.0-rc5-syzkaller #0 Not tainted
-------------------------------------
swapper/0/0 is trying to release lock (&dev->qdisc_xmit_lock_key) at:
[<ffffffff8625890d>] spin_unlock include/linux/spinlock.h:378 [inline]
[<ffffffff8625890d>] __netif_tx_unlock include/linux/netdevice.h:3966 [inline]
[<ffffffff8625890d>] __dev_queue_xmit+0x2bbd/0x35c0 net/core/dev.c:4016
but there are no more locks to release!

other info that might help us debug this:
4 locks held by swapper/0/0:
 #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: ffffffff899a5340 (rcu_read_lock){....}, at: ip6_nd_hdr net/ipv6/ndisc.c:463 [inline]
 #1: ffffffff899a5340 (rcu_read_lock){....}, at: ndisc_send_skb+0x7fe/0x1490 net/ipv6/ndisc.c:499
 #2: ffffffff899a5300 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline]
 #2: ffffffff899a5300 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x214/0x25c0 net/ipv6/ip6_output.c:102
 #3: ffffffff899a5300 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35c0 net/core/dev.c:3948

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/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:
 <IRQ>
 __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]
 __dev_queue_xmit+0x2bbd/0x35c0 net/core/dev.c:4016
 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_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
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 38 be db f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d c4 54 51 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d b4 54 51 00 fb f4 <c3> cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 5e 92 8b f9 e8 c9
RSP: 0018:ffffffff89807ce8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132669e RBX: ffffffff8987a140 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff8987a9d4
RBP: ffffffff89807d18 R08: ffffffff8987a140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffffff8a7b8600 R14: 0000000000000000 R15: 0000000000000000
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:690
 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x3c8/0x6e0 kernel/sched/idle.c:269
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361
 rest_init+0x23b/0x371 init/main.c:451
 arch_call_rest_init+0xe/0x1b
 start_kernel+0x904/0x943 init/main.c:784
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490
 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242
kobject: 'brport' (0000000015306f5c): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (0000000015306f5c): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (00000000f618ced7): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (00000000f618ced7): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (0000000090c32451): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (0000000090c32451): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (000000009b39b612): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (000000009b39b612): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (00000000fa23c3a6): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (00000000fa23c3a6): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (0000000059be53cf): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (0000000059be53cf): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (00000000afda9faa): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (00000000afda9faa): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (000000001b8d397b): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (000000001b8d397b): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (00000000c95708c8): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (00000000c95708c8): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (0000000021fa4c47): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (0000000021fa4c47): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (00000000e55a6ea3): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (00000000e55a6ea3): calling ktype release
kobject: 'brport': free name
kobject: 'brport' (000000005f707c44): kobject_cleanup, parent 00000000835b0c7d
kobject: 'brport' (000000005f707c44): calling ktype release
kobject: 'brport': free name

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/08 21:09 upstream ae6088216ce4 ddc3e859 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/01/07 21:29 upstream ae6088216ce4 1bcd407e .config console log report syz ci-upstream-kasan-gce
2020/01/07 21:45 upstream ae6088216ce4 1bcd407e .config console log report syz ci-upstream-kasan-gce-386
2020/01/11 03:04 upstream e69ec487b2c7 4de4e9f0 .config console log report ci-upstream-kasan-gce-selinux-root
2020/01/15 13:31 net-old 8c4df83fbe60 fa12bd3c .config console log report ci-upstream-net-this-kasan-gce
* Struck through repros no longer work on HEAD.