Re: WARNING in mem_cgroup_update_lru_size

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit:    96d4f267e40f Remove 'type' argument from access_ok() funct..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=160c9a80c00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7308e68273924137
dashboard link: https://syzkaller.appspot.com/bug?extid=c950a368703778078dc8
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=125376bb400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=121d85ab400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+c950a368703778078dc8@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
kasan: CONFIG_KASAN_INLINE enabled
mem_cgroup_update_lru_size(00000000d6ca43c5, 1, 1): lru_size -2032898272
kasan: GPF could be caused by NULL-ptr deref or user memory access
WARNING: CPU: 0 PID: 11430 at mm/memcontrol.c:1160  
mem_cgroup_update_lru_size+0xb2/0xe0 mm/memcontrol.c:1160
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 4 Comm:  Not tainted 4.20.0+ #8
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:191 [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+0xe8/0x5f0 kernel/sched/cputime.c:168
Code: 04 00 00 49 8b 84 24 00 07 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d  
b8 40 01 00 00 48 8d 88 28 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 93 03 00
RSP: 0018:ffff8880ae707a80 EFLAGS: 00010006
RAX: 0000000041b58ab3 RBX: 1ffff11015ce0f54 RCX: 0000000041b58bdb
RDX: dffffc0000000000 RSI: 000000000836b17e RDI: 0000000041b58bf3
RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: ffffffff8a9a805d
R10: ffffffff8a9a8050 R11: 0000000000000001 R12: ffff8880a94bc440
R13: 0000000000981859 R14: 0000000000000003 R15: ffff8880ae707b20
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006dae70 CR3: 0000000086205000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 irqtime_account_process_tick.isra.0+0x3a2/0x490 kernel/sched/cputime.c:380
 account_process_tick+0x27f/0x350 kernel/sched/cputime.c:483
 update_process_times+0x25/0x80 kernel/time/timer.c:1633
 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+0x3a7/0x1050 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+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
Modules linked in:
---[ end trace 42848964955b563b ]---
RIP: 0010:__read_once_size include/linux/compiler.h:191 [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+0xe8/0x5f0 kernel/sched/cputime.c:168
Code: 04 00 00 49 8b 84 24 00 07 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d  
b8 40 01 00 00 48 8d 88 28 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 93 03 00
RSP: 0018:ffff8880ae707a80 EFLAGS: 00010006
RAX: 0000000041b58ab3 RBX: 1ffff11015ce0f54 RCX: 0000000041b58bdb
RDX: dffffc0000000000 RSI: 000000000836b17e RDI: 0000000041b58bf3
RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: ffffffff8a9a805d
R10: ffffffff8a9a8050 R11: 0000000000000001 R12: ffff8880a94bc440
R13: 0000000000981859 R14: 0000000000000003 R15: ffff8880ae707b20
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006dae70 CR3: 0000000086205000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..