make sure we don't run over the end of 'name' in unix_convert()

Thanks to Andrew Bartlett for spotting this.
(This used to be commit b4c210ccb05e71a8ddf1c25d028452dd5cd93c72)

2 files changed, 21 insertions, 9 deletions

diff --git a/source3/lib/util_str.c b/source3/lib/util_str.c
index 3c34df6f33..17c7cc29fe 100644
--- a/source3/lib/util_str.c
+++ b/source3/lib/util_str.c
@@ -479,11 +479,15 @@ char *safe_strcat(char *dest, const char *src, size_t maxlength)
 	
 	src_len = strlen(src);
 	dest_len = strlen(dest);
-	
+
 	if (src_len + dest_len > maxlength) {
 		DEBUG(0,("ERROR: string overflow by %d in safe_strcat [%.50s]\n",
 			 (int)(src_len + dest_len - maxlength), src));
-		src_len = maxlength - dest_len;
+		if (maxlength > dest_len) {
+			memcpy(&dest[dest_len], src, maxlength - dest_len);
+		}
+		dest[maxlength] = 0;
+		return NULL;
 	}
 	
 	memcpy(&dest[dest_len], src, src_len);
diff --git a/source3/smbd/filename.c b/source3/smbd/filename.c
index bcfd366741..7d3527402e 100644
--- a/source3/smbd/filename.c
+++ b/source3/smbd/filename.c
@@ -31,7 +31,8 @@ extern BOOL case_preserve;
 extern BOOL short_case_preserve;
 extern BOOL use_mangled_map;
 
-static BOOL scan_directory(const char *path, pstring name,connection_struct *conn,BOOL docache);
+static BOOL scan_directory(const char *path, char *name,size_t maxlength,
+			   connection_struct *conn,BOOL docache);
 
 /****************************************************************************
  Check if two filenames are equal.
@@ -266,7 +267,11 @@ BOOL unix_convert(pstring name,connection_struct *conn,char *saved_last_componen
 			 * Try to find this part of the path in the directory.
 			 */
 
-			if (ms_has_wild(start) || !scan_directory(dirpath, start, conn, end?True:False)) {
+			if (ms_has_wild(start) || 
+			    !scan_directory(dirpath, start, 
+					    sizeof(pstring) - 1 - (start - name), 
+					    conn, 
+					    end?True:False)) {
 				if (end) {
 					/*
 					 * An intermediate part of the name can't be found.
@@ -315,8 +320,10 @@ BOOL unix_convert(pstring name,connection_struct *conn,char *saved_last_componen
 			 */
 			if (end) {
 				end = start + strlen(start);
-				pstrcat(start,"/");
-				pstrcat(start,rest);
+				if (!safe_strcat(start, "/", sizeof(pstring) - 1 - (start - name)) ||
+				    !safe_strcat(start, rest, sizeof(pstring) - 1 - (start - name))) {
+					return False;
+				}
 				*end = '\0';
 			} else {
 				/*
@@ -428,7 +435,8 @@ BOOL check_name(pstring name,connection_struct *conn)
  If the name looks like a mangled name then try via the mangling functions
 ****************************************************************************/
 
-static BOOL scan_directory(const char *path, pstring name,connection_struct *conn,BOOL docache)
+static BOOL scan_directory(const char *path, char *name, size_t maxlength, 
+			   connection_struct *conn,BOOL docache)
 {
 	void *cur_dir;
 	char *dname;
@@ -441,7 +449,7 @@ static BOOL scan_directory(const char *path, pstring name,connection_struct *con
 		path = ".";
 
 	if (docache && (dname = DirCacheCheck(path,name,SNUM(conn)))) {
-		pstrcpy(name, dname);	
+		safe_strcpy(name, dname, maxlength);	
 		return(True);
 	}      
 
@@ -481,7 +489,7 @@ static BOOL scan_directory(const char *path, pstring name,connection_struct *con
 			/* we've found the file, change it's name and return */
 			if (docache)
 				DirCacheAdd(path,name,dname,SNUM(conn));
-			pstrcpy(name, dname);
+			safe_strcpy(name, dname, maxlength);
 			CloseDir(cur_dir);
 			return(True);
 		}