INFO: rcu detected stall in garp_join_timer (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: b07f636f Merge tag 'tpmdd-next-20200108' of git://git.infr..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10f023fee00000
kernel config: https://syzkaller.appspot.com/x/.config?x=18698c0c240ba616
dashboard link: https://syzkaller.appspot.com/bug?extid=c2819430187dd4e41e7d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: i386
CC: [all...@lohutok.net da...@davemloft.net
gre...@linuxfoundation.org in...@metux.net kste...@linuxfoundation.org
linux-...@vger.kernel.org net...@vger.kernel.org tg...@linutronix.de]

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+c28194...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=59a/1/0x4000000000000004
softirq=98847/98848 fqs=2
(t=10501 jiffies g=120149 q=61)
rcu: rcu_preempt kthread starved for 10498 jiffies! g120149 f0x0
RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt I29128 10 2 0x80004000
Call Trace:
context_switch kernel/sched/core.c:3385 [inline]
__schedule+0x934/0x1f90 kernel/sched/core.c:4081
schedule+0xdc/0x2b0 kernel/sched/core.c:4155
schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895
rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1821
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 15833 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:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x23b/0x28b 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+0x183/0x1cf kernel/rcu/tree_stall.h:254
print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
rcu_pending kernel/rcu/tree.c:2827 [inline]
rcu_sched_clock_irq.cold+0x509/0xc0d kernel/rcu/tree.c:2271
update_process_times+0x2d/0x70 kernel/time/timer.c:1726
tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1310
__run_hrtimer kernel/time/hrtimer.c:1517 [inline]
__hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579
hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
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:lock_acquire+0x20b/0x410 kernel/locking/lockdep.c:4488
Code: 94 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 d3 01 00 00 48
83 3d 99 29 38 08 00 0f 84 53 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00
48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65 8b
RSP: 0018:ffffc90000007c70 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132669b RBX: ffff88805f268300 RCX: ffffffff815abea2
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282
RBP: ffffc90000007cb8 R08: 0000000000002d09 R09: fffffbfff165ebbe
R10: ffff88805f268c88 R11: ffff88805f268300 R12: ffff8880a44f7a70
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
garp_join_timer+0x25/0x80 net/802/garp.c:405
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:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:180
Code: ff cc cc cc cc cc cc cc cc cc 65 48 8b 04 25 c0 1e 02 00 48 8b 80 98
13 00 00 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 65
48 8b 04 25 c0 1e 02 00 65 8b 15 84 f7 8c 7e 81 e2
RSP: 0018:ffffc90001e377f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81a1dd06
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffffc90001e37818 R08: ffff88805f268300 R09: fffff94000502781
R10: fffff94000502780 R11: ffffea0002813c07 R12: ffffea0002813c40
R13: dead000000000100 R14: dffffc0000000000 R15: 0000000000000008
copy_one_pte mm/memory.c:790 [inline]
copy_pte_range mm/memory.c:841 [inline]
copy_pmd_range mm/memory.c:892 [inline]
copy_pud_range mm/memory.c:926 [inline]
copy_p4d_range mm/memory.c:948 [inline]
copy_page_range+0xd61/0x2190 mm/memory.c:1010
dup_mmap kernel/fork.c:604 [inline]
dup_mm+0xa67/0x1430 kernel/fork.c:1360
copy_mm kernel/fork.c:1416 [inline]
copy_process+0x2ad6/0x7230 kernel/fork.c:2072
_do_fork+0x146/0x1090 kernel/fork.c:2421
__do_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:253 [inline]
__se_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:236 [inline]
__ia32_compat_sys_x86_clone+0x190/0x270 arch/x86/ia32/sys_ia32.c:236
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f46a39
Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c
24 c3 8b 34 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d420cc EFLAGS: 00000296 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000025244000 RCX: 00000000200000c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
dccp_check_seqno: Step 6 failed for CLOSE packet, (LSWL(7359116173603) <=
P.seqno(7359116173602) <= S.SWH(7359116173677)) and (P.ackno exists or
LAWL(170087150637848) <= P.ackno(170087150637848) <=
S.AWH(170087150637848), sending SYNC...
dccp_check_seqno: Step 6 failed for CLOSE packet, (LSWL(202098969217393) <=
P.seqno(202098969217392) <= S.SWH(202098969217467)) and (P.ackno exists or
LAWL(210458026674701) <= P.ackno(210458026674701) <=
S.AWH(210458026674701), sending SYNC...


---
This bug is generated by a bot. It may contain errors.
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[Dmitry Vyukov]

#syz upstream

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