INFO: rcu detected stall in can_stat_update

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syzbot

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Dec 23, 2019, 8:40:10 PM12/23/19
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Hello,

syzbot found the following crash on:

HEAD commit: e1f7d50a Linux 4.14.160
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16a12ce1e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=46599517442ad9fb
dashboard link: https://syzkaller.appspot.com/bug?extid=cf8f737d0fe5bef3131d
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+cf8f73...@syzkaller.appspotmail.com

INFO: rcu_preempt self-detected stall on CPU
1-...: (1 GPs behind) idle=822/140000000000002/0 softirq=75513/75515 fqs=15
(t=10500 jiffies g=25544 c=25543 q=406)
rcu_preempt kthread starved for 10324 jiffies! g25544 c25543 f0x0
RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
rcu_preempt R running task 29776 8 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384
schedule+0x92/0x1c0 kernel/sched/core.c:3428
schedule_timeout+0x43e/0xe10 kernel/time/timer.c:1746
rcu_gp_kthread+0xbf4/0x1ec0 kernel/rcu/tree.c:2255
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
NMI backtrace for cpu 1
CPU: 1 PID: 20553 Comm: syz-executor.2 Not tainted 4.14.160-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:17 [inline]
dump_stack+0x142/0x197 lib/dump_stack.c:58
nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x141/0x189 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:158 [inline]
rcu_dump_cpu_stacks+0x186/0x1d2 kernel/rcu/tree.c:1396
print_cpu_stall kernel/rcu/tree.c:1542 [inline]
check_cpu_stall kernel/rcu/tree.c:1610 [inline]
__rcu_pending kernel/rcu/tree.c:3390 [inline]
rcu_pending kernel/rcu/tree.c:3452 [inline]
rcu_check_callbacks.cold+0x43d/0xd0a kernel/rcu/tree.c:2792
update_process_times+0x31/0x70 kernel/time/timer.c:1590
tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:161
tick_sched_timer+0x43/0x130 kernel/time/tick-sched.c:1219
__run_hrtimer kernel/time/hrtimer.c:1220 [inline]
__hrtimer_run_queues+0x270/0xbc0 kernel/time/hrtimer.c:1284
hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1318
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
smp_apic_timer_interrupt+0x11c/0x5e0 arch/x86/kernel/apic/apic.c:1100
apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:can_stat_update+0x498/0x9b0 net/can/proc.c:170
RSP: 0018:ffff8880aed07cf8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: dffffc0000000000 RBX: ffff88809b753600 RCX: 000000000000e7da
RDX: 1ffff110136ea6c9 RSI: ffffffff87f888e0 RDI: ffff88809b753660
RBP: ffff8880aed07d40 R08: ffff88809b753640 R09: ffffffff89594770
R10: ffff8880288a0c38 R11: ffff8880288a0340 R12: ffff888054e4c100
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88809b753668
call_timer_fn+0x161/0x670 kernel/time/timer.c:1279
expire_timers kernel/time/timer.c:1318 [inline]
__run_timers kernel/time/timer.c:1636 [inline]
__run_timers kernel/time/timer.c:1604 [inline]
run_timer_softirq+0x5b7/0x1520 kernel/time/timer.c:1649
__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: 0010:delete_from_page_cache+0x1/0x460 mm/filemap.c:266
RSP: 0018:ffff8880479476f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000040000 RBX: ffffea0001821f00 RCX: ffffc90009e38000
RDX: 00000000000236cf RSI: ffffffff81757210 RDI: ffffea0001821f00
RBP: ffff888047947720 R08: ffff8880288a0340 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea0001d1bbe0 R14: ffff88808f213638 R15: ffffea0001d1bbe0
truncate_inode_pages_range+0x206/0x13f0 mm/truncate.c:316
truncate_inode_pages mm/truncate.c:429 [inline]
truncate_pagecache+0x69/0x90 mm/truncate.c:761
ext4_setattr+0x124a/0x22e0 fs/ext4/inode.c:5516
notify_change+0x8d1/0xd10 fs/attr.c:313
do_truncate+0x124/0x1c0 fs/open.c:63
handle_truncate fs/namei.c:3009 [inline]
do_last fs/namei.c:3434 [inline]
path_openat+0x2786/0x3f70 fs/namei.c:3566
do_filp_open+0x18e/0x250 fs/namei.c:3600
do_sys_open+0x2c5/0x430 fs/open.c:1084
SYSC_open fs/open.c:1102 [inline]
SyS_open fs/open.c:1097 [inline]
SYSC_creat fs/open.c:1142 [inline]
SyS_creat+0x27/0x30 fs/open.c:1140
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a919
RSP: 002b:00007f017f933c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 000000000045a919
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000080
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f017f9346d4
R13: 00000000004c11be R14: 00000000004d5060 R15: 00000000ffffffff
INFO: rcu_sched detected stalls on CPUs/tasks:
1-...: (1 GPs behind) idle=822/140000000000002/0 softirq=75514/75515 fqs=16
(detected by 0, t=10557 jiffies, g=14012, c=14011, q=6)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 20553 Comm: syz-executor.2 Not tainted 4.14.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffff8880288a0340 task.stack: ffff888047940000
RIP: 0010:native_apic_msr_eoi_write+0xb/0x10 arch/x86/include/asm/apic.h:199
RSP: 0018:ffff8880aed076a0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff87c0c1a0 RCX: 000000000000080b
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000000b0
RBP: ffff8880aed076c0 R08: 000000b9795aaafc R09: ffff88821fff7048
R10: ffff88821fff7050 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f017f934700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd270fc4c8 CR3: 0000000054f7a000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
irq_work_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:823
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:queued_write_lock_slowpath+0x85/0x1d0 kernel/locking/qrwlock.c:130
RSP: 0018:ffff8880aed07780 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff09
RAX: 00000000000000ff RBX: ffffffff88981df0 RCX: 00000000d75703c6
RDX: 0000000000000000 RSI: ffff8880288a0cb0 RDI: ffffffff88981df0
RBP: ffff8880aed077b0 R08: 0000000000007bca R09: ffffffff8959d890
R10: ffff8880288a0cb0 R11: ffff8880288a0340 R12: ffffffff88981df4
R13: fffffbfff11303be R14: 0000000000000000 R15: 0000000000000001
queued_write_lock include/asm-generic/qrwlock.h:134 [inline]
do_raw_write_lock+0xc7/0x1d0 kernel/locking/spinlock_debug.c:203
__raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline]
_raw_write_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:320
__neigh_create+0x7b3/0x19f0 net/core/neighbour.c:534
ip6_finish_output2+0xab2/0x21b0 net/ipv6/ip6_output.c:117
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+0x12b/0x670 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:1636 [inline]
__run_timers kernel/time/timer.c:1604 [inline]
run_timer_softirq+0x5b7/0x1520 kernel/time/timer.c:1649
__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: 0010:delete_from_page_cache+0x1/0x460 mm/filemap.c:266
RSP: 0018:ffff8880479476f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000040000 RBX: ffffea0001821f00 RCX: ffffc90009e38000
RDX: 00000000000236cf RSI: ffffffff81757210 RDI: ffffea0001821f00
RBP: ffff888047947720 R08: ffff8880288a0340 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea0001d1bbe0 R14: ffff88808f213638 R15: ffffea0001d1bbe0
truncate_inode_pages_range+0x206/0x13f0 mm/truncate.c:316
truncate_inode_pages mm/truncate.c:429 [inline]
truncate_pagecache+0x69/0x90 mm/truncate.c:761
ext4_setattr+0x124a/0x22e0 fs/ext4/inode.c:5516
notify_change+0x8d1/0xd10 fs/attr.c:313
do_truncate+0x124/0x1c0 fs/open.c:63
handle_truncate fs/namei.c:3009 [inline]
do_last fs/namei.c:3434 [inline]
path_openat+0x2786/0x3f70 fs/namei.c:3566
do_filp_open+0x18e/0x250 fs/namei.c:3600
do_sys_open+0x2c5/0x430 fs/open.c:1084
SYSC_open fs/open.c:1102 [inline]
SyS_open fs/open.c:1097 [inline]
SYSC_creat fs/open.c:1142 [inline]
SyS_creat+0x27/0x30 fs/open.c:1140
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a919
RSP: 002b:00007f017f933c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 000000000045a919
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000080
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f017f9346d4
R13: 00000000004c11be R14: 00000000004d5060 R15: 00000000ffffffff
Code: 5f 00 eb a6 b8 da ff ff ff eb c7 0f 1f 44 00 00 55 be 01 00 00 00 48
89 e5 e8 22 db 24 00 5d c3 31 c0 b9 0b 08 00 00 89 c2 0f 30 <c3> 0f 1f 40
00 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00


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syzbot

unread,
Apr 21, 2020, 9:40:09 PM4/21/20
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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