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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 22162 on cpu 1:
 page_counter_try_charge+0x77/0x170 mm/page_counter.c:139
 try_charge+0x17f/0xbe0 mm/memcontrol.c:2405
 __memcg_kmem_charge_memcg+0x49/0xe0 mm/memcontrol.c:2837
 __memcg_kmem_charge+0xcd/0x1b0 mm/memcontrol.c:2877
 memcg_kmem_charge include/linux/memcontrol.h:1395 [inline]
 memcg_charge_kernel_stack kernel/fork.c:427 [inline]
 dup_task_struct kernel/fork.c:882 [inline]
 copy_process+0x12bc/0x3b10 kernel/fork.c:1931
 _do_fork+0xf7/0x790 kernel/fork.c:2441
 __do_sys_clone kernel/fork.c:2596 [inline]
 __se_sys_clone kernel/fork.c:2577 [inline]
 __x64_sys_clone+0x12e/0x170 kernel/fork.c:2577
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88821b672150 of 8 bytes by task 21732 on cpu 0:
 page_counter_try_charge+0x56/0x170 mm/page_counter.c:138
 try_charge+0x17f/0xbe0 mm/memcontrol.c:2405
 mem_cgroup_try_charge+0xd7/0x260 mm/memcontrol.c:6367
 mem_cgroup_try_charge_delay+0x36/0x70 mm/memcontrol.c:6382
 shmem_getpage_gfp+0x3f5/0x14c0 mm/shmem.c:1872
 shmem_getpage mm/shmem.c:154 [inline]
 shmem_write_begin+0x98/0x130 mm/shmem.c:2488
 generic_perform_write+0x13a/0x320 mm/filemap.c:3287
 __generic_file_write_iter+0x240/0x370 mm/filemap.c:3416
 generic_file_write_iter+0x294/0x38e mm/filemap.c:3448
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write+0x303/0x400 fs/read_write.c:483
 __vfs_write+0x9e/0xb0 fs/read_write.c:496
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:542
 ksys_pwrite64+0xe4/0x110 fs/read_write.c:665
 __do_sys_pwrite64 fs/read_write.c:675 [inline]
 __se_sys_pwrite64 fs/read_write.c:672 [inline]
 __x64_sys_pwrite64+0x5b/0x70 fs/read_write.c:672
 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: 0 PID: 21732 Comm: syz-executor.5 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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