syzbot

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BUG: KCSAN: data-race in __block_write_full_page / truncate_setsize

write to 0xffff888138e70ce8 of 8 bytes by task 16537 on cpu 0:
 i_size_write include/linux/fs.h:886 [inline]
 truncate_setsize+0x2a/0xc0 mm/truncate.c:775
 fat_setattr+0x893/0x9b0 fs/fat/file.c:549
 notify_change+0x9f8/0xb20 fs/attr.c:420
 do_truncate fs/open.c:65 [inline]
 do_sys_ftruncate+0x317/0x420 fs/open.c:193
 __do_sys_ftruncate fs/open.c:204 [inline]
 __se_sys_ftruncate fs/open.c:202 [inline]
 __x64_sys_ftruncate+0x2f/0x40 fs/open.c:202
 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 0xffff888138e70ce8 of 8 bytes by task 16532 on cpu 1:
 i_size_read include/linux/fs.h:864 [inline]
 __block_write_full_page+0xf3/0xb10 fs/buffer.c:1739
 block_write_full_page+0xda/0x100
 __mpage_writepage+0xb00/0xda0 fs/mpage.c:629
 write_cache_pages+0x443/0xa30 mm/page-writeback.c:2359
 mpage_writepages+0x6e/0xe0 fs/mpage.c:664
 fat_writepages+0x20/0x30 fs/fat/inode.c:205
 do_writepages+0x1db/0x350 mm/page-writeback.c:2468
 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 file_write_and_wait_range+0xd6/0x170 mm/filemap.c:773
 __generic_file_fsync+0x48/0x140 fs/libfs.c:1115
 fat_file_fsync+0x48/0x100 fs/fat/file.c:191
 vfs_fsync_range+0x107/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2869 [inline]
 generic_file_write_iter+0x18d/0x1c0 mm/filemap.c:3902
 do_iter_write+0x494/0x750 fs/read_write.c:855
 vfs_writev fs/read_write.c:928 [inline]
 do_writev+0x256/0x4b0 fs/read_write.c:971
 __do_sys_writev fs/read_write.c:1044 [inline]
 __se_sys_writev fs/read_write.c:1041 [inline]
 __x64_sys_writev+0x41/0x50 fs/read_write.c:1041
 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: 0x000000000000b000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16532 Comm: syz-executor.1 Not tainted 6.0.0-rc6-syzkaller-00009-g60891ec99e14-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
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