Prüfe auf Integer-Überlauf

1 files changed, 10 insertions, 4 deletions

diff --git a/csv.c b/csv.c
index 1ba3aa7..f154c12 100644
--- a/csv.c
+++ b/csv.c
@@ -25,22 +25,28 @@ csv_mem_allocate(size_t n, size_t sz, void *cb_arg)
 static void *
 csv_mem_reallocate(void *ptr, size_t n, size_t sz, void *cb_arg)
 {
-        void *reallocarray(void *ptr, size_t nmemb, size_t size);
+        size_t len;
 
         (void) cb_arg;
 
-        return reallocarray(ptr, n, sz);
+        if ( !__builtin_mul_overflow(n, sz, &len) ) {
+                return realloc(ptr, len);
+        }
+        return NULL;
 }
 
 static void
 csv_mem_free(void *ptr, size_t n, size_t sz, void *cb_arg)
 {
+        size_t len;
+
         void explicit_bzero(void *b, size_t len);
 
         (void) cb_arg;
 
-        // TODO: Check for overflow!
-        explicit_bzero(ptr, n * sz);
+        if ( !__builtin_mul_overflow(n, sz, &len) ) {
+                explicit_bzero(ptr, len);
+        }
         free(ptr);
 }