btrfs-progs: convert: copy whole xattr name buffer

kdave · kdave · commit 322929ece36d · 2024-06-25T17:05:04.000+02:00
Commit 4db9259 ("btrfs-progs: use strncpy_null everywhere") replaced strncpy with strncpy_null, the maximum xattr name length is 255 (current limit), the target buffer is large enough for the whole size so make sure the last character is also copied. Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/convert/source-ext2.c b/convert/source-ext2.c
@@ -639,7 +639,7 @@ static int ext2_copy_single_xattr(struct btrfs_trans_handle *trans,
 		data = databuf;
 		datalen = bufsize;
 	}
-	strncpy_null(namebuf, xattr_prefix_table[name_index], XATTR_NAME_MAX);
+	strncpy_null(namebuf, xattr_prefix_table[name_index], XATTR_NAME_MAX + 1);
 	strncat(namebuf, EXT2_EXT_ATTR_NAME(entry), entry->e_name_len);
 	if (name_len + datalen > BTRFS_LEAF_DATA_SIZE(root->fs_info) -
 	    sizeof(struct btrfs_item) - sizeof(struct btrfs_dir_item)) {

Original file line number	Diff line number	Diff line change
`@@ -639,7 +639,7 @@ static int ext2_copy_single_xattr(struct btrfs_trans_handle *trans,`
`639`	`639`	`data = databuf;`
`640`	`640`	`datalen = bufsize;`
`641`	`641`	`}`
`642`		`- strncpy_null(namebuf, xattr_prefix_table[name_index], XATTR_NAME_MAX);`
	`642`	`+ strncpy_null(namebuf, xattr_prefix_table[name_index], XATTR_NAME_MAX + 1);`
`643`	`643`	`strncat(namebuf, EXT2_EXT_ATTR_NAME(entry), entry->e_name_len);`
`644`	`644`	`if (name_len + datalen > BTRFS_LEAF_DATA_SIZE(root->fs_info) -`
`645`	`645`	`sizeof(struct btrfs_item) - sizeof(struct btrfs_dir_item)) {`