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BUG: KCSAN: data-race in block_page_mkwrite / generic_write_end

write to 0xffff88810af3c808 of 8 bytes by task 12780 on cpu 1:
 i_size_write include/linux/fs.h:886 [inline]
 generic_write_end+0xb1/0x350 fs/buffer.c:2168
 ext4_da_write_end+0x26c/0x620 fs/ext4/inode.c:3175
 generic_perform_write+0x264/0x3f0 mm/filemap.c:3783
 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:285
 ext4_file_write_iter+0x2bb/0x11b0
 call_write_iter include/linux/fs.h:2189 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x468/0x760 fs/read_write.c:584
 ksys_write+0xe8/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810af3c808 of 8 bytes by task 12781 on cpu 0:
 i_size_read include/linux/fs.h:864 [inline]
 block_page_mkwrite+0xb0/0x310 fs/buffer.c:2496
 ext4_page_mkwrite+0x7d6/0xfb0 fs/ext4/inode.c:6249
 do_page_mkwrite mm/memory.c:2947 [inline]
 wp_page_shared+0x265/0x5d0 mm/memory.c:3295
 do_wp_page+0xca/0x640 mm/memory.c:3377
 handle_pte_fault mm/memory.c:4949 [inline]
 __handle_mm_fault mm/memory.c:5073 [inline]
 handle_mm_fault+0x644/0xb20 mm/memory.c:5219
 do_user_addr_fault+0x4a1/0x980 arch/x86/mm/fault.c:1428
 handle_page_fault arch/x86/mm/fault.c:1519 [inline]
 exc_page_fault+0x60/0x160 arch/x86/mm/fault.c:1575
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
 copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:165
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 copyout+0x72/0x90 lib/iov_iter.c:170
 _copy_to_iter+0x288/0x910 lib/iov_iter.c:529
 copy_page_to_iter+0x31b/0x450 lib/iov_iter.c:727
 copy_folio_to_iter include/linux/uio.h:172 [inline]
 filemap_read+0x11db/0x1510 mm/filemap.c:2745
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2840
 ext4_file_read_iter+0x1c8/0x280
 do_iter_read+0x492/0x760 fs/read_write.c:796
 vfs_readv fs/read_write.c:916 [inline]
 do_preadv+0x159/0x230 fs/read_write.c:1008
 __do_sys_preadv fs/read_write.c:1058 [inline]
 __se_sys_preadv fs/read_write.c:1053 [inline]
 __x64_sys_preadv+0x54/0x60 fs/read_write.c:1053
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000fab000 -> 0x0000000000fac000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12781 Comm: syz-executor.5 Not tainted 6.2.0-rc4-syzkaller-00009-gd532dd102151-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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