BUG: soft lockup in br_handle_frame

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 414510bc Linux 4.14.142
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17d35826600000
kernel config: https://syzkaller.appspot.com/x/.config?x=9aa0b2ccd827f416
dashboard link: https://syzkaller.appspot.com/bug?extid=3f599ae172cb5609847c
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3f599a...@syzkaller.appspotmail.com

hugetlbfs: syz-executor.3 (7560): Using mlock ulimits for SHM_HUGETLB is
deprecated
usb usb5: usbfs: process 7560 (syz-executor.3) did not claim interface 0
before use
watchdog: BUG: soft lockup - CPU#1 stuck for 123s! [ksoftirqd/1:17]
Modules linked in:
irq event stamp: 33816031
hardirqs last enabled at (33816030): [<ffffffff86200979>]
restore_regs_and_return_to_kernel+0x0/0x27
hardirqs last disabled at (33816031): [<ffffffff86201b01>]
apic_timer_interrupt+0x91/0xa0 arch/x86/entry/entry_64.S:792
softirqs last enabled at (33787342): [<ffffffff86400645>]
__do_softirq+0x645/0x9a0 kernel/softirq.c:314
softirqs last disabled at (33787347): [<ffffffff8138b9dc>] run_ksoftirqd
kernel/softirq.c:670 [inline]
softirqs last disabled at (33787347): [<ffffffff8138b9dc>]
run_ksoftirqd+0x8c/0x1b0 kernel/softirq.c:662
CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.14.142 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffff8880a9d5c480 task.stack: ffff8880a9d60000
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:661 [inline]
RIP: 0010:virt_spin_lock arch/x86/include/asm/qspinlock.h:87 [inline]
RIP: 0010:native_queued_spin_lock_slowpath+0x302/0x750
kernel/locking/qspinlock.c:313
RSP: 0018:ffff8880a9d66c68 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000001 RBX: ffff88807a91d720 RCX: dffffc0000000000
RDX: 1ffffffff0ee2a98 RSI: 0000000000000001 RDI: ffff88807a91d720
RBP: ffff8880a9d66c98 R08: 0000000000000001 R09: ffff8880a9d66a28
R10: ffff8880a9d669f8 R11: ffff8880a9d5c480 R12: 0000000000000001
R13: 0000000000000003 R14: ffffed100f523ae4 R15: ffff88807a91d768
FS: 0000000000000000(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fecc015b008 CR3: 000000008f2e3000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:669 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:52 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:90 [inline]
do_raw_spin_lock+0x190/0x230 kernel/locking/spinlock_debug.c:113
__raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_lock+0x37/0x40 kernel/locking/spinlock.c:152
spin_lock include/linux/spinlock.h:317 [inline]
__dev_xmit_skb net/core/dev.c:3204 [inline]
__dev_queue_xmit+0x11c0/0x25e0 net/core/dev.c:3493
dev_queue_xmit+0x18/0x20 net/core/dev.c:3558
br_dev_queue_push_xmit+0x367/0x530 net/bridge/br_forward.c:55
br_nf_dev_queue_xmit+0x307/0x1440 net/bridge/br_netfilter_hooks.c:776
NF_HOOK include/linux/netfilter.h:250 [inline]
NF_HOOK include/linux/netfilter.h:244 [inline]
br_nf_post_routing+0xb80/0xf00 net/bridge/br_netfilter_hooks.c:822
nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline]
nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467
nf_hook include/linux/netfilter.h:205 [inline]
NF_HOOK include/linux/netfilter.h:248 [inline]
br_forward_finish+0x1b7/0x320 net/bridge/br_forward.c:67
br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005
br_nf_forward_finish+0x264/0x640 net/bridge/br_netfilter_hooks.c:550
NF_HOOK include/linux/netfilter.h:250 [inline]
NF_HOOK include/linux/netfilter.h:244 [inline]
br_nf_forward_ip net/bridge/br_netfilter_hooks.c:617 [inline]
br_nf_forward_ip+0x5fc/0x11d0 net/bridge/br_netfilter_hooks.c:561
nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline]
nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467
nf_hook include/linux/netfilter.h:205 [inline]
NF_HOOK include/linux/netfilter.h:248 [inline]
__br_forward+0x312/0x9c0 net/bridge/br_forward.c:111
deliver_clone+0x61/0xc0 net/bridge/br_forward.c:127
br_flood+0x43c/0x530 net/bridge/br_forward.c:222
br_handle_frame_finish+0xaf0/0x1830 net/bridge/br_input.c:210
br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005
br_nf_pre_routing_finish_ipv6+0x621/0xc50
net/bridge/br_netfilter_ipv6.c:210
NF_HOOK include/linux/netfilter.h:250 [inline]
br_nf_pre_routing_ipv6+0x417/0x790 net/bridge/br_netfilter_ipv6.c:240
br_nf_pre_routing+0xdce/0x12c7 net/bridge/br_netfilter_hooks.c:491
nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline]
nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467
nf_hook include/linux/netfilter.h:205 [inline]
NF_HOOK include/linux/netfilter.h:248 [inline]
br_handle_frame+0x80c/0x1110 net/bridge/br_input.c:348
__netif_receive_skb_core+0x789/0x2ca0 net/core/dev.c:4431
__netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4515
process_backlog+0x21f/0x730 net/core/dev.c:5197
napi_poll net/core/dev.c:5598 [inline]
net_rx_action+0x490/0xf80 net/core/dev.c:5664
__do_softirq+0x244/0x9a0 kernel/softirq.c:288
run_ksoftirqd kernel/softirq.c:670 [inline]
run_ksoftirqd+0x8c/0x1b0 kernel/softirq.c:662
smpboot_thread_fn+0x5f4/0x960 kernel/smpboot.c:164
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: 4c 89 e2 48 c1 ea 03 80 3c 02 00 0f 85 6b 03 00 00 49 8b 04 24 48 85
c0 0f 84 54 01 00 00 48 89 c1 0f 18 08 e9 4b 01 00 00 f3 90 <e9> 37 fd ff
ff 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6873 Comm: syz-fuzzer Not tainted 4.14.142 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffff888096a58080 task.stack: ffff8880a4f80000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:list_empty include/linux/list.h:203 [inline]
RIP: 0010:hhf_dequeue+0x5d/0xa60 net/sched/sch_hhf.c:426
RSP: 0000:ffff8880aee07680 EFLAGS: 00000246
RAX: ffffed100f523b20 RBX: ffff88807a91d878 RCX: 0000000000000000
RDX: 0000000000000100 RSI: ffff88807a91d910 RDI: ffff88807a91d880
RBP: ffff8880aee076d0 R08: 0000000000000000 R09: ffff888096a589e8
R10: ffff888096a589c8 R11: ffff888096a58080 R12: dffffc0000000000
R13: ffff88807a91d680 R14: ffff88807a91d910 R15: ffff88807a91d900
FS: 000000c4203c8090(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c43f4cb010 CR3: 0000000092b53000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
dequeue_skb net/sched/sch_generic.c:148 [inline]
qdisc_restart net/sched/sch_generic.c:241 [inline]
__qdisc_run+0x2b8/0xe00 net/sched/sch_generic.c:257
__dev_xmit_skb net/core/dev.c:3235 [inline]
__dev_queue_xmit+0x1571/0x25e0 net/core/dev.c:3493
dev_queue_xmit+0x18/0x20 net/core/dev.c:3558
neigh_hh_output include/net/neighbour.h:490 [inline]
neigh_output include/net/neighbour.h:498 [inline]
ip6_finish_output2+0x10bd/0x21b0 net/ipv6/ip6_output.c:120
ip6_finish_output+0x4f4/0xb50 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:239 [inline]
ip6_output+0x20f/0x6d0 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:462 [inline]
NF_HOOK include/linux/netfilter.h:250 [inline]
ndisc_send_skb+0xb56/0x11e0 net/ipv6/ndisc.c:483
ndisc_send_rs+0x129/0x680 net/ipv6/ndisc.c:677
addrconf_rs_timer+0x289/0x5a0 net/ipv6/addrconf.c:3757
call_timer_fn+0x161/0x670 kernel/time/timer.c:1279
expire_timers kernel/time/timer.c:1318 [inline]
__run_timers kernel/time/timer.c:1634 [inline]
__run_timers kernel/time/timer.c:1602 [inline]
run_timer_softirq+0x5b4/0x1570 kernel/time/timer.c:1647
__do_softirq+0x244/0x9a0 kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x160/0x1b0 kernel/softirq.c:409
exiting_irq arch/x86/include/asm/apic.h:648 [inline]
smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1102
apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
</IRQ>
RIP: 0033:0x41d493
RSP: 002b:000000c420251e90 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff10
RAX: 000000c420000000 RBX: 000000c41fe6da1a RCX: 0000000000000000
RDX: 000000c43f560000 RSI: 000000c42324bca0 RDI: 0000000000000000
RBP: 000000c420251f28 R08: 0000000000000000 R09: 00000000009e5e80
R10: 0000000000000020 R11: 000000c42324bca0 R12: 0000000000000000
R13: 00000000000000f3 R14: 0000000000000033 R15: 0000000000000080
Code: 01 e0 48 89 45 c8 49 8d 85 90 02 00 00 48 89 45 d0 48 c1 e8 03 48 89
45 c0 e8 f0 55 6d fc 48 8b 45 c8 80 38 00 0f 85 53 07 00 00 <49> 8b 85 80
02 00 00 4d 89 fe 49 39 c7 0f 84 3e 04 00 00 e8 cb


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.