strlcpy: Check for maxlen underflow

ClusterLabs#429
chrissie-c · Jan 4, 2021 · fe0258f · fe0258f · wferi · Jan 4, 2021
1 parent 5b16d50
commit fe0258f
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/lib/strlcpy.c b/lib/strlcpy.c
@@ -33,7 +33,8 @@ strlcpy(char *dest, const char * src, size_t maxlen)
 	size_t	srclen = strlen(src);
 	size_t	len2cpy = QB_MIN(maxlen-1, srclen);
 
-	if (len2cpy > 0) {
+	// check maxlen separately as it could have underflowed from 0 above.
+	if (maxlen && len2cpy > 0) {
 		strncpy(dest, src, len2cpy+1);
 		dest[len2cpy] = '\0';
 	}