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BUG: KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers

write to 0xffff88810aa13ae8 of 8 bytes by task 4110 on cpu 1:
 __remove_assoc_queue fs/buffer.c:524 [inline]
 fsync_buffers_list fs/buffer.c:728 [inline]
 sync_mapping_buffers+0x165/0x7d0 fs/buffer.c:591
 fat_file_fsync+0xad/0x100 fs/fat/file.c:195
 vfs_fsync_range+0x10b/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2452 [inline]
 generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4090
 do_iter_write+0x418/0x700 fs/read_write.c:861
 vfs_iter_write+0x50/0x70 fs/read_write.c:902
 iter_file_splice_write+0x456/0x7d0 fs/splice.c:778
 do_splice_from fs/splice.c:856 [inline]
 direct_splice_actor+0x84/0xa0 fs/splice.c:1022
 splice_direct_to_actor+0x2ee/0x5f0 fs/splice.c:977
 do_splice_direct+0x104/0x180 fs/splice.c:1065
 do_sendfile+0x3b8/0x950 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810aa13ae8 of 8 bytes by task 4101 on cpu 0:
 mark_buffer_dirty_inode+0x96/0x1c0 fs/buffer.c:624
 fat_mirror_bhs+0x212/0x310 fs/fat/fatent.c:398
 fat_ent_write+0xc6/0xe0 fs/fat/fatent.c:423
 fat_chain_add+0x15f/0x400 fs/fat/misc.c:136
 fat_add_cluster fs/fat/inode.c:113 [inline]
 __fat_get_block fs/fat/inode.c:155 [inline]
 fat_get_block+0x467/0x5e0 fs/fat/inode.c:190
 __block_write_begin_int+0x349/0xe50 fs/buffer.c:2034
 __block_write_begin fs/buffer.c:2084 [inline]
 block_write_begin+0x7c/0x180 fs/buffer.c:2145
 cont_write_begin+0x4c0/0x6f0 fs/buffer.c:2504
 fat_write_begin+0x61/0xf0 fs/fat/inode.c:230
 generic_perform_write+0x1c3/0x3d0 mm/filemap.c:3926
 __generic_file_write_iter+0xe6/0x290 mm/filemap.c:4054
 generic_file_write_iter+0x7d/0x1c0 mm/filemap.c:4086
 call_write_iter include/linux/fs.h:1851 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x45a/0x750 fs/read_write.c:584
 ksys_write+0xeb/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+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffff88810aa12e90 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4101 Comm: syz-executor.3 Not tainted 6.3.0-rc4-syzkaller-00224-g00c7b5f4ddc5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
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