keyword: Fix a major issue with `get_keyword_offset_ptr()` adding the

offset before dereferencing `ret`, and also check if the dereferenced
return pointer is NULL

1 files changed, 5 insertions, 1 deletions

diff --git a/keyword.c b/keyword.c
index 385f526..3a87c13 100644
--- a/keyword.c
+++ b/keyword.c
@@ -13,7 +13,11 @@
 void *get_keyword_offset_ptr(const keyword *key, void *ptr) {
 	char *ret = (char *)(ptr+key->offsets[0]);
 	for (int i = 1; (int64_t)key->offsets[i] >= 0; ++i) {
-		ret = *(char **)(ret+key->offsets[i]);
+		if (*(char **)ret != NULL) {
+			ret = (*(char **)ret)+key->offsets[i];
+		} else {
+			return NULL;
+		}
 	}
 	return (void *)ret;
 }