5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hao-Qun Huang commit 28c1ef094e7c86977d9bf570dc0362fc54e36437 upstream. F2FS_IOC_MOVE_RANGE treats a zero length as a request to move data from pos_in to EOF. However, the same-file overlap check runs before that expansion, so a request with len == 0 bypasses the overlap rejection added for same-file moves. For example, with a four-block file, moving from block 0 to block 1 with len == 0 is accepted by the old check because pos_in + len is still pos_in at that point. The code then expands len to cover the rest of the file and calls __exchange_data_block() on overlapping source and destination ranges in the same inode, which is the data-corruption case the overlap check was meant to reject. Move the overlap check after the source range has been validated and len == 0 has been expanded, so it sees the effective length. This is a no-op for non-zero len (the value is unchanged there) and keeps the existing early return for identical positions. Fixes: d95fd91c1ac1 ("f2fs: exclude special cases for f2fs_move_file_range") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-fable-5 Signed-off-by: Hao-Qun Huang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2870,8 +2870,6 @@ static int f2fs_move_file_range(struct f if (src == dst) { if (pos_in == pos_out) return 0; - if (pos_out > pos_in && pos_out < pos_in + len) - return -EINVAL; } inode_lock(src); @@ -2892,6 +2890,8 @@ static int f2fs_move_file_range(struct f goto out_unlock; if (len == 0) olen = len = src->i_size - pos_in; + if (src == dst && pos_out > pos_in && pos_out < pos_in + len) + goto out_unlock; if (pos_in + len == src->i_size) len = ALIGN(src->i_size, F2FS_BLKSIZE) - pos_in; if (len == 0) {