INFO: rcu detected stall in mrp_join_timer (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e69ec487 Merge branch 'for-linus' of git://git.kernel.org/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=148f85c6e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=18698c0c240ba616
dashboard link: https://syzkaller.appspot.com/bug?extid=77b752dc2aa35a2107d1
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [da...@davemloft.net gre...@linuxfoundation.org
kees...@chromium.org kste...@linuxfoundation.org
linux-...@vger.kernel.org net...@vger.kernel.org
pankaj.laxmina...@intel.com 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+77b752...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10498 ticks this GP) idle=276/1/0x4000000000000004
softirq=118059/118059 fqs=5
(t=10501 jiffies g=171025 q=88)
rcu: rcu_preempt kthread starved for 10492 jiffies! g171025 f0x0
RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt R running task 28952 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 1
CPU: 1 PID: 13224 Comm: syz-executor.1 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160
[inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x90/0xe0
kernel/locking/spinlock.c:191
Code: 48 c7 c0 d8 34 93 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c
10 00 75 39 48 83 3d cf f3 bb 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00
bf 01 00 00 00 e8 b1 79 79 f9 65 8b 05 62 dd 2a 78
RSP: 0018:ffffc90000da8bc8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132669b RBX: 0000000000000282 RCX: 0000000000000002
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282
RBP: ffffc90000da8bd8 R08: 1ffffffff165ebbb R09: fffffbfff165ebbc
R10: fffffbfff165ebbb R11: ffffffff8b2f5ddf R12: ffff8880ae927240
R13: ffff8880ae927240 R14: ffff8880ae927240 R15: ffff8880ae927240
__mod_timer kernel/time/timer.c:1057 [inline]
mod_timer+0x507/0xc10 kernel/time/timer.c:1100
mrp_join_timer_arm+0x5e/0x80 net/802/mrp.c:583
mrp_join_timer+0x79/0x80 net/802/mrp.c:596
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:preempt_schedule_irq+0xab/0x160 kernel/sched/core.c:4338
Code: 00 00 e8 78 aa 7a f9 e8 e3 96 a4 f9 4c 89 f0 48 c1 e8 03 80 3c 18 00
75 7d 48 83 3d 36 0f bd 01 00 74 6f fb 66 0f 1f 44 00 00 <bf> 01 00 00 00
e8 ab d1 ff ff 48 c7 c0 e0 34 93 89 48 c1 e8 03 80
RSP: 0018:ffffc9000875f8b8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132669d RBX: dffffc0000000000 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888056e0cd14
RBP: ffffc9000875f8d8 R08: 1ffffffff165eba7 R09: fffffbfff165eba8
R10: fffffbfff165eba7 R11: ffffffff8b2f5d3f R12: ffffed100adc1890
R13: ffff888056e0c480 R14: ffffffff899334e8 R15: 0000000000000000
retint_kernel+0x1b/0x2b
RIP: 0010:__kasan_check_read+0x1/0x20 mm/kasan/common.c:95
Code: bf 1c 06 8b 5d c4 e9 55 9e ff ff 48 8b 73 58 89 c2 48 c7 c7 48 3b 42
89 f7 da e8 de b9 ab ff e9 3e ef ff ff cc cc cc cc cc 55 <89> f6 31 d2 48
89 e5 48 8b 4d 08 e8 1f 2a 00 00 5d c3 0f 1f 00 66
RSP: 0018:ffffc9000875f990 EFLAGS: 00000216 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: 0000000000000028 RCX: ffffc900049c9000
RDX: 00000000000156dc RSI: 0000000000000028 RDI: ffffc9000875fa30
RBP: ffffc9000875f9d0 R08: ffff888056e0c480 R09: ffff888056e0cd10
R10: fffffbfff14f70f8 R11: ffffffff8a7b87c7 R12: 00000000007160a8
R13: ffffc9000875fa30 R14: 00000000007160d0 R15: 00007ffffffff000
copy_to_user include/linux/uaccess.h:152 [inline]
inet_gifconf+0x23c/0x490 net/ipv4/devinet.c:1268
dev_ifconf+0xd0/0x230 net/core/dev_ioctl.c:80
sock_do_ioctl+0x260/0x2f0 net/socket.c:1054
sock_ioctl+0x3ed/0x790 net/socket.c:1191
vfs_ioctl fs/ioctl.c:47 [inline]
file_ioctl fs/ioctl.c:545 [inline]
do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
__do_sys_ioctl fs/ioctl.c:756 [inline]
__se_sys_ioctl fs/ioctl.c:754 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd77d100c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000007
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd77d1016d4
R13: 00000000004c4f66 R14: 00000000004dba00 R15: 00000000ffffffff


---
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[Dmitry Vyukov]

#syz upstream

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