syzbot

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BUG: KCSAN: data-race in drain_all_stock / try_charge

write to 0xffff88812c02a288 of 4 bytes by task 8680 on cpu 0:
 consume_stock mm/memcontrol.c:2066 [inline]
 try_charge+0x35f/0xbe0 mm/memcontrol.c:2400
 mem_cgroup_try_charge+0xd7/0x260 mm/memcontrol.c:6367
 mem_cgroup_try_charge_delay+0x36/0x70 mm/memcontrol.c:6382
 wp_page_copy+0x31a/0xf20 mm/memory.c:2516
 do_wp_page+0x185/0xcc0 mm/memory.c:2812
 handle_pte_fault mm/memory.c:4049 [inline]
 __handle_mm_fault+0x1c5e/0x2cf0 mm/memory.c:4163
 handle_mm_fault+0x21c/0x540 mm/memory.c:4200
 do_user_addr_fault arch/x86/mm/fault.c:1442 [inline]
 do_page_fault+0x4a4/0xa52 arch/x86/mm/fault.c:1517
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203

read to 0xffff88812c02a288 of 4 bytes by task 8638 on cpu 1:
 drain_all_stock mm/memcontrol.c:2159 [inline]
 drain_all_stock+0xdb/0x250 mm/memcontrol.c:2138
 try_charge+0x78b/0xbe0 mm/memcontrol.c:2462
 mem_cgroup_try_charge+0xd7/0x260 mm/memcontrol.c:6367
 mem_cgroup_try_charge_delay+0x36/0x70 mm/memcontrol.c:6382
 do_anonymous_page mm/memory.c:3190 [inline]
 handle_pte_fault mm/memory.c:4031 [inline]
 __handle_mm_fault+0x18f1/0x2cf0 mm/memory.c:4163
 handle_mm_fault+0x21c/0x540 mm/memory.c:4200
 faultin_page mm/gup.c:659 [inline]
 __get_user_pages+0x485/0x1140 mm/gup.c:870
 populate_vma_page_range+0xdc/0x100 mm/gup.c:1181
 __mm_populate+0x168/0x2b0 mm/gup.c:1229
 mm_populate include/linux/mm.h:2343 [inline]
 __do_sys_mlockall mm/mlock.c:823 [inline]
 __se_sys_mlockall mm/mlock.c:799 [inline]
 __x64_sys_mlockall+0x2d6/0x310 mm/mlock.c:799
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8638 Comm: syz-executor.2 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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