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BUG: KCSAN: data-race in page_counter_try_charge / page_counter_try_charge

write to 0xffff88821b672150 of 8 bytes by task 16754 on cpu 1:
 page_counter_try_charge+0x7e/0x170 mm/page_counter.c:139
 try_charge+0x185/0xbf0 mm/memcontrol.c:2405
 mem_cgroup_try_charge+0xd2/0x260 mm/memcontrol.c:6367
 __add_to_page_cache_locked+0x163/0x780 mm/filemap.c:844
 add_to_page_cache_lru+0xc4/0x260 mm/filemap.c:921
 pagecache_get_page+0x2ac/0x6f0 mm/filemap.c:1660
 grab_cache_page_write_begin+0x5d/0x90 mm/filemap.c:3237
 ext4_da_write_begin+0x1a3/0x840 fs/ext4/inode.c:2966
 generic_perform_write+0x136/0x320 mm/filemap.c:3287
 ext4_buffered_write_iter+0x143/0x290 fs/ext4/file.c:270
 ext4_file_write_iter+0xfa/0xd70 fs/ext4/file.c:642
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483
 __vfs_write+0xb1/0xc0 fs/read_write.c:496
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88821b672150 of 8 bytes by task 16737 on cpu 0:
 page_counter_try_charge+0x58/0x170 mm/page_counter.c:138
 try_charge+0x185/0xbf0 mm/memcontrol.c:2405
 mem_cgroup_try_charge+0xd2/0x260 mm/memcontrol.c:6367
 mem_cgroup_try_charge_delay+0x3a/0x80 mm/memcontrol.c:6382
 shmem_getpage_gfp+0x3bf/0x1390 mm/shmem.c:1872
 shmem_fault+0x114/0x470 mm/shmem.c:2067
 __do_fault+0xae/0x1f0 mm/memory.c:3276
 do_read_fault mm/memory.c:3673 [inline]
 do_fault mm/memory.c:3802 [inline]
 handle_pte_fault mm/memory.c:4033 [inline]
 __handle_mm_fault+0x270d/0x2e00 mm/memory.c:4163
 handle_mm_fault+0x21b/0x530 mm/memory.c:4200
 faultin_page mm/gup.c:659 [inline]
 __get_user_pages+0x485/0x1130 mm/gup.c:870
 populate_vma_page_range+0xe6/0x100 mm/gup.c:1181
 __mm_populate+0x168/0x2a0 mm/gup.c:1229
 mm_populate include/linux/mm.h:2343 [inline]
 vm_mmap_pgoff+0x181/0x190 mm/util.c:511
 ksys_mmap_pgoff+0x99/0x420 mm/mmap.c:1597
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:99 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:90 [inline]
 __x64_sys_mmap+0x2e/0x40 arch/x86/kernel/sys_x86_64.c:90
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16737 Comm: syz-executor.1 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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