INFO: rcu detected stall in dst_destroy

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 14cfdbd3 Linux 4.19.112
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12085923e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=48ea0e0a21a4900f
dashboard link: https://syzkaller.appspot.com/bug?extid=77ef55fc66f3565c017f
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+77ef55...@syzkaller.appspotmail.com

ISOFS: Unable to identify CD-ROM format.
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (1 GPs behind) idle=12e/1/0x4000000000000004 softirq=874493/874494 fqs=5193
rcu: (t=10500 jiffies g=629637 q=345683)
NMI backtrace for cpu 0
CPU: 0 PID: 24286 Comm: syz-executor.3 Not tainted 4.19.112-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+0x188/0x20d lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
rcu_dump_cpu_stacks+0x170/0x1bb 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+0x634/0xddc kernel/rcu/tree.c:2682
update_process_times+0x2a/0x70 kernel/time/timer.c:1638
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168
tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1401 [inline]
__hrtimer_run_queues+0x2fc/0xd50 kernel/time/hrtimer.c:1463
hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:kmem_cache_free+0xa4/0x260 mm/slab.c:3766
Code: e8 31 2f 00 00 84 c0 74 76 41 f7 c4 00 02 00 00 74 4e e8 2f 82 cf ff 48 83 3d cf 20 15 07 00 0f 84 a8 01 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 4c 8b 64 24 20 0f 1f 44 00 00 65 8b 05 56 4b 64 7e
RSP: 0018:ffff8880ae607db8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: ffff888098952f00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8880912c4e80 RDI: 0000000000000286
RBP: ffff8880a77e06c0 R08: ffff8880912c4600 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000286
R13: ffffffff859f6e4f R14: ffff888098952f08 R15: ffff888098952f38
dst_destroy+0x27f/0x3a0 net/core/dst.c:141
__rcu_reclaim kernel/rcu/rcu.h:236 [inline]
rcu_do_batch kernel/rcu/tree.c:2584 [inline]
invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
__rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
rcu_process_callbacks+0xb2d/0x17f0 kernel/rcu/tree.c:2881
__do_softirq+0x26c/0x93c kernel/softirq.c:292
invoke_softirq kernel/softirq.c:372 [inline]
irq_exit+0x17b/0x1c0 kernel/softirq.c:412
exiting_irq arch/x86/include/asm/apic.h:544 [inline]
smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893
</IRQ>
RIP: 0010:__schedule+0x8d0/0x1d80 kernel/sched/core.c:3522
Code: 83 b8 88 0a 00 00 00 0f 85 c9 0b 00 00 48 8b 8d 60 ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 c7 04 01 00 00 00 00 48 8b 45 d0 <65> 48 33 04 25 28 00 00 00 0f 85 51 11 00 00 48 81 c4 a8 00 00 00
RSP: 0018:ffff88804c6df4a0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 000ae7a2e9cbfb00 RBX: ffff8880ae62c298 RCX: 1ffff110098dbe9d
RDX: 1ffff11015cc59a1 RSI: 0000000000000004 RDI: ffff8880ae62cd08
RBP: ffff88804c6df570 R08: ffff8880912c4600 R09: ffffed101228fc4c
R10: ffffed101228fc4b R11: ffff88809147e25f R12: ffff8880a1258480
R13: 0000000000000000 R14: ffff8880912c4600 R15: ffff8880ae62c280
preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:3742
retint_kernel+0x1b/0x2d
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:317 [inline]
RIP: 0010:test_ti_thread_flag include/linux/thread_info.h:84 [inline]
RIP: 0010:need_resched include/linux/sched.h:1737 [inline]
RIP: 0010:preempt_schedule_common+0x5d/0xc0 kernel/sched/core.c:3647
Code: e1 e3 78 25 ff ff ff 7f 83 f8 01 74 2e bf 01 00 00 00 e8 16 d8 ff ff 65 8b 05 8f e1 e3 78 65 ff 0d 88 e1 e3 78 80 3b 00 75 4c <49> 8b 45 00 a8 08 75 c3 5b 5d 41 5c 41 5d 41 5e c3 4c 8b 74 24 28
RSP: 0018:ffff88804c6df650 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02
RAX: 0000000080000001 RBX: ffffed10122588c0 RCX: 1ffff110098dbeb7
RDX: 1ffff11015cc59a1 RSI: 0000000000000004 RDI: ffff8880ae62cd08
RBP: ffff8880912c4600 R08: ffff8880912c4600 R09: ffffed101228fc4c
R10: ffffed101228fc4b R11: ffff88809147e25f R12: dffffc0000000000
R13: ffff8880912c4600 R14: ffffffff810061f2 R15: 0000000000000000
___preempt_schedule+0x16/0x18
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
_raw_spin_unlock_irqrestore+0xb7/0xe0 kernel/locking/spinlock.c:184
__debug_check_no_obj_freed lib/debugobjects.c:798 [inline]
debug_check_no_obj_freed+0x20a/0x42e lib/debugobjects.c:817
free_pages_prepare mm/page_alloc.c:1055 [inline]
free_pcp_prepare mm/page_alloc.c:1069 [inline]
free_unref_page_prepare mm/page_alloc.c:2761 [inline]
free_unref_page_list+0x1e6/0xc10 mm/page_alloc.c:2830
release_pages+0x5d6/0x18f0 mm/swap.c:800
tlb_flush_mmu_free+0x72/0x140 mm/memory.c:249
tlb_flush_mmu mm/memory.c:258 [inline]
arch_tlb_finish_mmu+0x224/0x510 mm/memory.c:273
tlb_finish_mmu+0x97/0x100 mm/memory.c:432
exit_mmap+0x2d2/0x510 mm/mmap.c:3093
__mmput kernel/fork.c:1015 [inline]
mmput+0x14e/0x4a0 kernel/fork.c:1036
exit_mm kernel/exit.c:546 [inline]
do_exit+0xac8/0x2f30 kernel/exit.c:867
do_group_exit+0x125/0x350 kernel/exit.c:983
get_signal+0x3ec/0x1f90 kernel/signal.c:2588
do_signal+0x8f/0x1710 arch/x86/kernel/signal.c:821
exit_to_usermode_loop+0x22b/0x2b0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c849
Code: Bad RIP value.
RSP: 002b:00007f7cc0b2fcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000076bf08 RCX: 000000000045c849
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000076bf08
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000076bf0c
R13: 00007ffd47df644f R14: 00007f7cc0b309c0 R15: 000000000076bf0c


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[syzbot]

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