INFO: rcu detected stall in __perf_sw_event

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f0a7d1883d9f afs: Fix clearance of reply
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15bdf9e9400000
kernel config: https://syzkaller.appspot.com/x/.config?x=b3f55cb3dfcc6c33
dashboard link: https://syzkaller.appspot.com/bug?extid=64c25a544413a5e455f7
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [ar...@arndb.de boris.o...@oracle.com b...@alien8.de
h...@zytor.com joao.m....@oracle.com linux-...@vger.kernel.org
mi...@redhat.com pbon...@redhat.com rkr...@redhat.com tg...@linutronix.de
x...@kernel.org]

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+64c25a...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (10499 ticks this GP) idle=1e6/1/0x4000000000000002
softirq=262888/262888 fqs=5211
rcu: (t=10500 jiffies g=395777 q=692)
NMI backtrace for cpu 0
CPU: 0 PID: 13255 Comm: syz-executor3 Not tainted 4.19.0-rc8+ #64
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+0x1c4/0x2b4 lib/dump_stack.c:113
nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:162 [inline]
rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1340
print_cpu_stall.cold.78+0x2d3/0x524 kernel/rcu/tree.c:1478
check_cpu_stall kernel/rcu/tree.c:1550 [inline]
__rcu_pending kernel/rcu/tree.c:3276 [inline]
rcu_pending kernel/rcu/tree.c:3319 [inline]
rcu_check_callbacks+0xfd9/0x1990 kernel/rcu/tree.c:2665
update_process_times+0x2d/0x70 kernel/time/timer.c:1636
tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
__run_hrtimer kernel/time/hrtimer.c:1398 [inline]
__hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1460
hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline]
smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1054
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864
</IRQ>
RIP: 0010:__pvclock_read_cycles arch/x86/include/asm/pvclock.h:85 [inline]
RIP: 0010:pvclock_clocksource_read+0x1dc/0x6a0 arch/x86/kernel/pvclock.c:87
Code: ff 4c 89 c6 48 c1 ea 03 83 e6 07 44 0f be 5b 1c 42 0f b6 14 22 48 89
f9 48 c1 e9 03 40 38 f2 42 0f b6 0c 21 40 0f 9e c6 84 d2 <0f> 95 c2 40 84
d6 0f 85 cb 02 00 00 83 e7 07 40 38 f9 40 0f 9e c6
RSP: 0018:ffff88017f216538 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 00000567483b195b RBX: ffffffff8a2fd000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8a2fd01b
RBP: ffff88017f216628 R08: ffffffff8a2fd018 R09: 0000000000000016
R10: fffffbfff145fa01 R11: 00000000ffffffff R12: dffffc0000000000
R13: ffffffff8a2fd003 R14: ffffffff8a2fd01d R15: ffffffff8a2fd010
kvm_clock_read+0x18/0x30 arch/x86/kernel/kvmclock.c:103
kvm_sched_clock_read+0x9/0x20 arch/x86/kernel/kvmclock.c:115
paravirt_sched_clock arch/x86/include/asm/paravirt.h:175 [inline]
sched_clock+0x31/0x40 arch/x86/kernel/tsc.c:245
sched_clock_cpu+0x1b/0x1b0 kernel/sched/clock.c:370
local_clock include/linux/sched/clock.h:84 [inline]
cpu_clock_event_update+0x1b/0x50 kernel/events/core.c:9203
cpu_clock_event_read+0x15/0x20 kernel/events/core.c:9236
perf_output_read_group kernel/events/core.c:6108 [inline]
perf_output_read+0x13a5/0x1920 kernel/events/core.c:6147
perf_output_sample+0xd88/0x1df0 kernel/events/core.c:6189
__perf_event_output kernel/events/core.c:6511 [inline]
perf_event_output_forward+0x185/0x2d0 kernel/events/core.c:6524
__perf_event_overflow+0x239/0x4c0 kernel/events/core.c:7768
perf_swevent_overflow+0xad/0x150 kernel/events/core.c:7844
perf_swevent_event+0x1f0/0x2e0 kernel/events/core.c:7877
do_perf_sw_event kernel/events/core.c:7985 [inline]
___perf_sw_event+0x4a9/0x7c0 kernel/events/core.c:8016
__perf_sw_event+0x4f/0x90 kernel/events/core.c:8028
perf_sw_event include/linux/perf_event.h:1054 [inline]
__do_page_fault+0x7ec/0xed0 arch/x86/mm/fault.c:1436
do_page_fault+0xf2/0x7e0 arch/x86/mm/fault.c:1470
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20
arch/x86/lib/copy_user_64.S:180
Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f
80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 <f3> a4 31 c0 0f
1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 83
RSP: 0018:ffff88017f2176b8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000008000 RCX: 0000000000003440
RDX: 0000000000008000 RSI: 0000000020f75000 RDI: ffff88019db64bc0
RBP: ffff88017f2176f0 R08: 0000000000000000 R09: 0000000000000200
R10: ffffed0033b6cfff R11: ffff88019db67fff R12: 0000000020f78440
R13: 0000000020f70440 R14: ffff88019db60000 R15: 00007ffffffff000
_copy_from_iter_full+0x25e/0xd20 lib/iov_iter.c:724
copy_from_iter_full include/linux/uio.h:124 [inline]
skb_do_copy_data_nocache include/net/sock.h:1949 [inline]
skb_copy_to_page_nocache include/net/sock.h:1975 [inline]
kcm_sendmsg+0x179c/0x24b0 net/kcm/kcmsock.c:990
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:631
sock_write_iter+0x35e/0x5c0 net/socket.c:900
call_write_iter include/linux/fs.h:1808 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x6b8/0x9f0 fs/read_write.c:487
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7819781c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 00000000fffffd70 RSI: 0000000020000440 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f78197826d4
R13: 00000000004c553a R14: 00000000004d8e68 R15: 00000000ffffffff
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-... }
10619 jiffies s: 15205 root: 0x1/.
rcu: blocking rcu_node structures:
Task dump for CPU 0:
syz-executor3 R running task 20896 13255 5592 0x8000000c
Call Trace:


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot.

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: b0314565da2b Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15cd5e73400000
kernel config: https://syzkaller.appspot.com/x/.config?x=8f00801d7b7c4fe6
dashboard link: https://syzkaller.appspot.com/bug?extid=64c25a544413a5e455f7
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1707cd2f400000
CC: [ac...@kernel.org alexander...@linux.intel.com
jo...@redhat.com linux-...@vger.kernel.org mi...@redhat.com
namh...@kernel.org pet...@infradead.org]

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+64c25a...@syzkaller.appspotmail.com

8021q: adding VLAN 0 to HW filter on device batadv0

rcu: INFO: rcu_preempt self-detected stall on CPU

rcu: 0-....: (10499 ticks this GP) idle=d02/1/0x4000000000000002
softirq=13779/13779 fqs=5238
rcu: (t=10500 jiffies g=11657 q=1546)

NMI backtrace for cpu 0

CPU: 0 PID: 9826 Comm: syz-executor0 Not tainted 5.0.0-rc5+ #61

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+0x1be/0x236 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.c:1211
print_cpu_stall kernel/rcu/tree.c:1348 [inline]
check_cpu_stall kernel/rcu/tree.c:1422 [inline]
rcu_pending kernel/rcu/tree.c:3018 [inline]
rcu_check_callbacks.cold+0x500/0xa4a kernel/rcu/tree.c:2521
update_process_times+0x32/0x80 kernel/time/timer.c:1635
tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
__run_hrtimer kernel/time/hrtimer.c:1389 [inline]
__hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
</IRQ>
RIP: 0010:memcpy_erms+0x8/0x10 arch/x86/lib/memcpy_64.S:56
Code: 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5
89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 f3 a4 <c3> 0f 1f 80 00
00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe 7c 35
RSP: 0018:ffff88808fd171b8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff888092eb1798 RBX: 0000000000000868 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffff88808fd17348 RDI: ffff888092eb17a8
RBP: ffff88808fd171d8 R08: 1ffff110125d62f3 R09: ffffed10125d62f5
R10: ffffed10125d62f4 R11: ffff888092eb17a7 R12: 0000000000000010
R13: ffff888092eb1798 R14: ffff88808fd17338 R15: ffff88808fd17550
memcpy include/linux/string.h:352 [inline]
memcpy_common kernel/events/internal.h:172 [inline]
__output_copy kernel/events/internal.h:176 [inline]
perf_output_read_group kernel/events/core.c:6114 [inline]
perf_output_read+0xe16/0x1390 kernel/events/core.c:6147
perf_output_sample+0x13b9/0x1a90 kernel/events/core.c:6189
__perf_event_output kernel/events/core.c:6511 [inline]
perf_event_output_forward+0x150/0x290 kernel/events/core.c:6524
__perf_event_overflow+0x144/0x360 kernel/events/core.c:7768
perf_swevent_overflow+0xaa/0x140 kernel/events/core.c:7844
perf_swevent_event+0x1f7/0x2f0 kernel/events/core.c:7877
do_perf_sw_event kernel/events/core.c:7985 [inline]
___perf_sw_event+0x31c/0x570 kernel/events/core.c:8016
__perf_sw_event+0x51/0xa0 kernel/events/core.c:8028
perf_sw_event include/linux/perf_event.h:1054 [inline]
do_user_addr_fault arch/x86/mm/fault.c:1516 [inline]
__do_page_fault+0x734/0xd60 arch/x86/mm/fault.c:1541
do_page_fault+0x71/0x581 arch/x86/mm/fault.c:1572
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20
arch/x86/lib/copy_user_64.S:181

Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f
80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 <f3> a4 31 c0 0f
1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 83

RSP: 0018:ffff88808fd17b40 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000340
RDX: 0000000000001000 RSI: 000000002081d000 RDI: ffff88808b047cc0
RBP: ffff88808fd17b78 R08: ffffed1011609000 R09: 0000000000000000
R10: ffffed1011608fff R11: ffff88808b047fff R12: 000000002081c340
R13: ffff88808b047000 R14: 000000002081d340 R15: 00007ffffffff000
copy_page_from_iter_iovec lib/iov_iter.c:294 [inline]
copy_page_from_iter+0x324/0x750 lib/iov_iter.c:907
pipe_write+0x27d/0xfb0 fs/pipe.c:429
call_write_iter include/linux/fs.h:1863 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x613/0x8e0 fs/read_write.c:487
vfs_write+0x20c/0x580 fs/read_write.c:549
ksys_write+0xea/0x1f0 fs/read_write.c:598

__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607

do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457e39
Code: ad b8 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 b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f21b6591c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39
RDX: 0000000041395527 RSI: 0000000020000340 RDI: 0000000000000006
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f21b65926d4
R13: 00000000004c3c0e R14: 00000000004dc3a8 R15: 00000000ffffffff

[Dmitry Vyukov]

#syz upstream

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