common, trust: Avoid integer overflow

This fixes issues pointed in:
https://bugzilla.redhat.com/show_bug.cgi?id=985445
except for p11-kit/conf.c:read_config_file(), which was rewritten using
mmap() and thus length calculation is no longer needed.

1 files changed, 1 insertions, 1 deletions

diff --git a/common/url.c b/common/url.c
index 4b7e47b..884c584 100644
--- a/common/url.c
+++ b/common/url.c
@@ -71,7 +71,7 @@ p11_url_decode (const char *value,
 		 */
 		if (*value == '%') {
 			value++;
-			if (value + 2 > end) {
+			if (end - value < 2) {
 				free (result);
 				return NULL;
 			}