loop1: detected capacity change from 0 to 8192
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BUG: KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers

write to 0xffff88810655cd58 of 8 bytes by task 9530 on cpu 1:
 __remove_assoc_queue fs/buffer.c:523 [inline]
 fsync_buffers_list fs/buffer.c:791 [inline]
 sync_mapping_buffers+0x165/0x7d0 fs/buffer.c:584
 fat_file_fsync+0xad/0x100 fs/fat/file.c:195
 vfs_fsync_range+0x111/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2584 [inline]
 generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4094
 __kernel_write_iter+0x162/0x3c0 fs/read_write.c:517
 __kernel_write+0x90/0xc0 fs/read_write.c:537
 __dump_emit fs/coredump.c:813 [inline]
 dump_emit+0x1a7/0x270 fs/coredump.c:850
 writenote+0x10a/0x190 fs/binfmt_elf.c:1487
 write_note_info fs/binfmt_elf.c:1969 [inline]
 elf_core_dump+0x17c3/0x1ba0 fs/binfmt_elf.c:2129
 do_coredump+0x1029/0x1890 fs/coredump.c:764
 get_signal+0xda3/0x1090 kernel/signal.c:2878
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:309
 irqentry_exit+0x12/0x40 kernel/entry/common.c:412
 exc_general_protection+0x339/0x4c0 arch/x86/kernel/traps.c:642
 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:564

read to 0xffff88810655cd58 of 8 bytes by task 9523 on cpu 0:
 mark_buffer_dirty_inode+0x96/0x1c0 fs/buffer.c:687
 fat_mirror_bhs+0x212/0x310 fs/fat/fatent.c:398
 fat_alloc_clusters+0x973/0xa60 fs/fat/fatent.c:543
 fat_add_cluster fs/fat/inode.c:108 [inline]
 __fat_get_block fs/fat/inode.c:155 [inline]
 fat_get_block+0x25c/0x5e0 fs/fat/inode.c:190
 __block_write_begin_int+0x3c3/0xf50 fs/buffer.c:2120
 __block_write_begin fs/buffer.c:2169 [inline]
 block_write_begin+0x7b/0x170 fs/buffer.c:2228
 cont_write_begin+0x479/0x690 fs/buffer.c:2585
 fat_write_begin+0x61/0xf0 fs/fat/inode.c:230
 generic_perform_write+0x1c9/0x410 mm/filemap.c:3969
 __generic_file_write_iter+0xa1/0x120 mm/filemap.c:4064
 generic_file_write_iter+0x7d/0x1c0 mm/filemap.c:4090
 call_write_iter include/linux/fs.h:1956 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x4ab/0x7d0 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: 0xffff88810657d440 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9523 Comm: syz-executor.1 Not tainted 6.6.0-rc5-syzkaller-00250-g70f8c6f8f880 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
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