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BUG: KCSAN: data-race in next_uptodate_folio / shmem_write_end

write to 0xffff888104296410 of 8 bytes by task 4393 on cpu 1:
 i_size_write include/linux/fs.h:932 [inline]
 shmem_write_end+0x9a/0x470 mm/shmem.c:2741
 generic_perform_write+0x267/0x410 mm/filemap.c:3941
 shmem_file_write_iter+0xc8/0xe0 mm/shmem.c:2893
 call_write_iter include/linux/fs.h:2085 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x760/0x8d0 fs/read_write.c:590
 ksys_write+0xeb/0x1a0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888104296410 of 8 bytes by task 4395 on cpu 0:
 i_size_read include/linux/fs.h:910 [inline]
 next_uptodate_folio+0x5c9/0x7a0 mm/filemap.c:3420
 filemap_map_pages+0x708/0x900 mm/filemap.c:3568
 do_fault_around mm/memory.c:4696 [inline]
 do_read_fault mm/memory.c:4729 [inline]
 do_fault mm/memory.c:4868 [inline]
 do_pte_missing mm/memory.c:3745 [inline]
 handle_pte_fault mm/memory.c:5144 [inline]
 __handle_mm_fault mm/memory.c:5285 [inline]
 handle_mm_fault+0x1063/0x27b0 mm/memory.c:5450
 faultin_page mm/gup.c:958 [inline]
 __get_user_pages+0x402/0xe40 mm/gup.c:1241
 populate_vma_page_range mm/gup.c:1679 [inline]
 __mm_populate+0x216/0x330 mm/gup.c:1788
 mm_populate include/linux/mm.h:3391 [inline]
 vm_mmap_pgoff+0x1a7/0x240 mm/util.c:561
 ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1425
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000c29000 -> 0x0000000000c2c000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4395 Comm: syz-executor.0 Not tainted 6.8.0-rc1-syzkaller-00029-g615d30064886 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
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