INFO: rcu detected stall in inet_sendmsg

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 0fed55c2 Linux 4.19.70
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=173ed0b2600000
kernel config: https://syzkaller.appspot.com/x/.config?x=2964bf2f89c3f203
dashboard link: https://syzkaller.appspot.com/bug?extid=6d5f9777df889103c4db
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+6d5f97...@syzkaller.appspotmail.com

protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10499 ticks this GP) idle=f72/1/0x4000000000000002
softirq=251172/251172 fqs=40
rcu: (t=10501 jiffies g=407705 q=103)
rcu: rcu_preempt kthread starved for 10422 jiffies! g407705 f0x0
RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt I29008 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_timeout+0x4db/0xfc0 kernel/time/timer.c:1804
rcu_gp_kthread+0xd5c/0x2190 kernel/rcu/tree.c:2202
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
NMI backtrace for cpu 1
CPU: 1 PID: 21171 Comm: syz-executor.5 Not tainted 4.19.70 #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+0x172/0x1f0 lib/dump_stack.c:113
nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
rcu_dump_cpu_stacks+0x189/0x1d5 kernel/rcu/tree.c:1340
print_cpu_stall kernel/rcu/tree.c:1478 [inline]
check_cpu_stall kernel/rcu/tree.c:1550 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold+0x5e3/0xd90 kernel/rcu/tree.c:2682
update_process_times+0x32/0x80 kernel/time/timer.c:1636
tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:164
tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1274
__run_hrtimer kernel/time/hrtimer.c:1398 [inline]
__hrtimer_run_queues+0x33b/0xdc0 kernel/time/hrtimer.c:1460
hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1518
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x111/0x550 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893
</IRQ>
RIP: 0010:hhf_dequeue+0x557/0xa00 net/sched/sch_hhf.c:435
Code: 48 39 c2 74 34 e8 89 dd dc fb 49 8d bd 6c 03 00 00 48 89 f8 48 c1 e8
03 42 0f b6 14 20 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 91
03 00 00 45 8b b5 6c 03 00 00 e8 55 dd dc fb 49 8d
RSP: 0018:ffff88801592ed18 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: ffff88805dbd1938 RCX: ffffc900108c4000
RDX: 0000000000000000 RSI: ffffffff858e8907 RDI: ffff88805dbd19ec
RBP: ffff88801592ed68 R08: ffff8880a7b14680 R09: 0000000000000006
R10: ffff8880a7b14ff0 R11: 000000000b9ec47c R12: dffffc0000000000
R13: ffff88805dbd1680 R14: 0000000000000001 R15: 0000000000000000
dequeue_skb net/sched/sch_generic.c:277 [inline]
qdisc_restart net/sched/sch_generic.c:380 [inline]
__qdisc_run+0x1e7/0x1960 net/sched/sch_generic.c:398
__dev_xmit_skb net/core/dev.c:3501 [inline]
__dev_queue_xmit+0x165c/0x2fe0 net/core/dev.c:3811
dev_queue_xmit+0x18/0x20 net/core/dev.c:3876
br_dev_queue_push_xmit+0x405/0x5d0 net/bridge/br_forward.c:56
NF_HOOK include/linux/netfilter.h:289 [inline]
NF_HOOK include/linux/netfilter.h:283 [inline]
br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:69
NF_HOOK include/linux/netfilter.h:289 [inline]
NF_HOOK include/linux/netfilter.h:283 [inline]
__br_forward+0x647/0xb30 net/bridge/br_forward.c:113
deliver_clone+0x61/0xc0 net/bridge/br_forward.c:129
maybe_deliver net/bridge/br_forward.c:184 [inline]
maybe_deliver net/bridge/br_forward.c:172 [inline]
br_flood+0x4da/0x710 net/bridge/br_forward.c:226
br_dev_xmit+0xeeb/0x1490 net/bridge/br_device.c:103
__netdev_start_xmit include/linux/netdevice.h:4303 [inline]
netdev_start_xmit include/linux/netdevice.h:4312 [inline]
xmit_one net/core/dev.c:3257 [inline]
dev_hard_start_xmit+0x1a5/0x980 net/core/dev.c:3273
__dev_queue_xmit+0x2704/0x2fe0 net/core/dev.c:3843
dev_queue_xmit+0x18/0x20 net/core/dev.c:3876
neigh_resolve_output net/core/neighbour.c:1369 [inline]
neigh_resolve_output+0x5b7/0x980 net/core/neighbour.c:1349
neigh_output include/net/neighbour.h:501 [inline]
ip_finish_output2+0x93d/0x1730 net/ipv4/ip_output.c:229
ip_finish_output+0x737/0xce0 net/ipv4/ip_output.c:317
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip_output+0x225/0x650 net/ipv4/ip_output.c:405
dst_output include/net/dst.h:447 [inline]
ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:124
ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1442
ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1462
raw_sendmsg+0x1e60/0x2b80 net/ipv4/raw.c:677
inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
__sys_sendto+0x262/0x380 net/socket.c:1787
__do_sys_sendto net/socket.c:1799 [inline]
__se_sys_sendto net/socket.c:1795 [inline]
__x64_sys_sendto+0xe1/0x1a0 net/socket.c:1795
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fab1ff4cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459879
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 00000000200000c0 R09: 000000000000006e
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fab1ff4d6d4
R13: 00000000004c78ab R14: 00000000004dd1c8 R15: 00000000ffffffff


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

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