[PATCH v2 1/2] cifs: alloc_path_with_tree_prefix: do not append sep. if the path is empty

[PATCH v2 1/2] cifs: alloc_path_with_tree_prefix: do not append sep. if the path is empty

[Eugene Korenevsky]

alloc_path_with_tree_prefix() concatenates tree prefix and the path.
Windows CIFS client does not add separator after the tree prefix if the path
is empty. Let's do the same.

This fixes mounting DFS namespaces with names containing non-ASCII symbols.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215440
Signed-off-by: Eugene Korenevsky <ekorenevsky@astralinux.ru>
---
v2: The patch is included in the patchset for #215440 fix

 fs/cifs/smb2pdu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 8b3670388cda..88ea0163257c 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2527,8 +2527,13 @@ alloc_path_with_tree_prefix(__le16 **out_path, int *out_size, int *out_len,
 
 	cp = load_nls_default();
 	cifs_strtoUTF16(*out_path, treename, treename_len, cp);
-	UniStrcat(*out_path, sep);
-	UniStrcat(*out_path, path);
+
+	/* Do not append the separator if the path is empty */
+	if (path[0] != cpu_to_le16(0x0000)) {
+		UniStrcat(*out_path, sep);
+		UniStrcat(*out_path, path);
+	}
+
 	unload_nls(cp);
 
 	return 0;
-- 
2.30.2