Check that buffer does not contain UTF-16 null codepoint
because Linux cannot process symlink with null byte.
Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
---
fs/smb/client/reparse.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
index 5a738f65b190..ca4f96c43508 100644
--- a/fs/smb/client/reparse.c
+++ b/fs/smb/client/reparse.c
@@ -509,6 +509,16 @@ int smb2_parse_native_symlink(char **target, const char *buf, unsigned int len,
int rc;
int i;
+ /*
+ * Check that buffer does not contain UTF-16 null codepoint
+ * because Linux cannot process symlink with null byte.
+ */
+ if (unicode && UniStrnlen((wchar_t *)buf, len/2) != len/2) {
+ cifs_dbg(VFS, "srv returned null byte in native symlink target location\n");
+ rc = -EIO;
+ goto out;
+ }
+
smb_target = cifs_strndup_from_utf16(buf, len, unicode, cifs_sb->local_nls);
if (!smb_target) {
rc = -ENOMEM;
--
2.20.1
