Convert trailing spaces and periods in path components

stable inclusion
from linux-4.19.158
commit 987c45d57f388f9531d523b8424b8e97687bb323

--------------------------------

commit 57c17607 upstream.

When converting trailing spaces and periods in paths, do so
for every component of the path, not just the last component.
If the conversion is not done for every path component, then
subsequent operations in directories with trailing spaces or
periods (e.g. create(), mkdir()) will fail with ENOENT. This
is because on the server, the directory will have a special
symbol in its name, and the client needs to provide the same.
Signed-off-by: NBoris Protopopov <pboris@amazon.com>
Acked-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

fs/cifs/cifs_unicode.c

@@ -501,7 +501,13 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
 		else if (map_chars == SFM_MAP_UNI_RSVD) {
 			bool end_of_string;
 
-			if (i == srclen - 1)
+			/**
+			 * Remap spaces and periods found at the end of every
+			 * component of the path. The special cases of '.' and
+			 * '..' do not need to be dealt with explicitly because
+			 * they are addressed in namei.c:link_path_walk().
+			 **/
+			if ((i == srclen - 1) || (source[i+1] == '\\'))
 				end_of_string = true;
 			else
 				end_of_string = false;