BUG: unable to handle kernel paging request in account_system_index_time

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 8ae71e76cf1f Merge branch 'bpf-offload-sharing'
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15e6b51c400000
kernel config: https://syzkaller.appspot.com/x/.config?x=89129667b46496c3
dashboard link: https://syzkaller.appspot.com/bug?extid=8c02c0836b162b8737e5
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [fwei...@gmail.com linux-...@vger.kernel.org
mi...@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+8c02c0...@syzkaller.appspotmail.com

EXT4-fs (sda1): re-mounted. Opts:
kasan: CONFIG_KASAN_INLINE enabled
BUG: unable to handle kernel paging request at ffff8801cada54f8
kasan: GPF could be caused by NULL-ptr deref or user memory access
PGD b4e2067 P4D b4e2067 PUD 1d9469063 PMD 1ba03a063 PTE 0
Thread overran stack, or stack corrupted
Oops: 0000 [#1] SMP KASAN
CPU: 0 PID: 20315 Comm: syz-executor5 Not tainted 4.18.0-rc3+ #58
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline]
RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149
[inline]
RIP: 0010:account_system_index_time+0x10a/0x5c0 kernel/sched/cputime.c:168
Code: 00 48 8d 88 20 01 00 00 48 89 fe 48 c1 ee 03 0f b6 14 16 48 89 fe 83
e6 07 40 38 f2 7f 08 84 d2 0f 85 f9 03 00 00 4d 8d 67 80 <0f> b6 b0 38 01
00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 e7 48 c1
RSP: 0018:ffff8801dae07988 EFLAGS: 00010046
RAX: ffff8801cada53c0 RBX: ffff8801c53ca0c0 RCX: ffff8801cada54e0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801cada54f8
RBP: ffff8801dae07a68 R08: ffff8801c53ca0c0 R09: fffffbfff11f424c
R10: fffffbfff11c1b45 R11: ffffffff88fa1263 R12: ffff8801dae079c0
R13: 00000000000f4240 R14: 1ffff1003b5c0f34 R15: ffff8801dae07a40
FS: 000000000231a940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8801cada54f8 CR3: 00000001b2bcd000 CR4: 00000000001406f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
account_system_time+0x7f/0xb0 kernel/sched/cputime.c:199
account_process_tick+0x76/0x240 kernel/sched/cputime.c:498
update_process_times+0x21/0x70 kernel/time/timer.c:1634
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+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1050
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
</IRQ>
Modules linked in:
Dumping ftrace buffer:
(ftrace buffer empty)
CR2: ffff8801cada54f8
---[ end trace 29e68111158e7e5b ]---
general protection fault: 0000 [#2] SMP KASAN
CPU: 1 PID: 20334 Comm: syz-executor4 Tainted: G D
4.18.0-rc3+ #58
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline]
RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149
[inline]
RIP: 0010:account_system_index_time+0x10a/0x5c0 kernel/sched/cputime.c:168
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Code:
RIP: 0010:find_stack lib/stackdepot.c:188 [inline]
RIP: 0010:depot_save_stack+0x120/0x470 lib/stackdepot.c:238
00
Code: 0f
48
00 4e
8d
8b
88
24
20
f5 c0
01
3a
00
c3
00
8a
48
4d
89
85
fe
e4
48
0f
c1
84
ee
d4
03
00
0f
00
b6
00
14
44
16
8d 47
48 89
ff
fe
49
83
c1
e6
e0
07 40
03
38
eb
f2
0d
7f
4d
08
8b
84 d2
24
0f
24
85
4d
f9
85
03
e4 0f
00
84
00
bd
4d
00
8d 67
00
80
00
<0f>
<41>
b6
39
b0
5c
38
24
01
08
00
75
00
ec
48 ba
41
00
3b
00
7c
00
24
00
0c
00
75
fc
e5
ff
48
df
8b
4c
01
89 e7
49
48
39
c1
44
RSP: 0018:ffff8801dae07988 EFLAGS: 00010046
24
18
RAX: ffff8801cada53c0 RBX: ffff8801c53ca0c0 RCX: ffff8801cada54e0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801cada54f8
RSP: 0018:ffff88019ca0f858 EFLAGS: 00010286
RBP: ffff8801dae07a68 R08: ffff8801c53ca0c0 R09: fffffbfff11f424c
R10: fffffbfff11c1b45 R11: ffffffff88fa1263 R12: ffff8801dae079c0
RAX: 0000000095734edc RBX: 0000000096b0f28b RCX: ffff88019ca0f8b8
R13: 00000000000f4240 R14: 1ffff1003b5c0f34 R15: ffff8801dae07a40
RDX: 00000000f6a9df25 RSI: 00000000006000c0 RDI: 000000000000000b
FS: 000000000231a940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
RBP: ffff88019ca0f890 R08: 0000000000000050 R09: 000000002cc8a8f1
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
R10: 000000005f6a6738 R11: ffff8801daf236b3 R12: fc0000000000ba48
CR2: ffff8801cada54f8 CR3: 00000001b2bcd000 CR4: 00000000001406f0
R13: ffff88019ca0f8a0 R14: 000000000000f28b R15: ffff8801ac364f37
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
FS: 00000000024f6940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033


---
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[Dmitry Vyukov]

Looks like the bpf map bug:
#syz fix: bpf: sockhash, disallow bpf_tcp_close and update in parallel

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