From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Mon, 4 May 2020 17:46:45 +0000 (+0200)
Subject: Prevent division by zero in linkhash.
X-Git-Tag: json-c-0.15-20200726~58^2~2^2~1
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=77d935b7ae7871a1940cd827e850e6063044ec45;p=json-c

Prevent division by zero in linkhash.

If a linkhash with a size of zero is created, then modulo operations
are prone to division by zero operations.

Purely protective measure against bad usage.
---

diff --git a/linkhash.c b/linkhash.c
index 7ea58c0..f05cc38 100644
--- a/linkhash.c
+++ b/linkhash.c
@@ -12,6 +12,7 @@
 
 #include "config.h"
 
+#include <assert.h>
 #include <limits.h>
 #include <stdarg.h>
 #include <stddef.h>
@@ -499,6 +500,8 @@ struct lh_table *lh_table_new(int size, lh_entry_free_fn *free_fn, lh_hash_fn *h
 	int i;
 	struct lh_table *t;
 
+	/* Allocate space for elements to avoid divisions by zero. */
+	assert(size > 0);
 	t = (struct lh_table *)calloc(1, sizeof(struct lh_table));
 	if (!t)
 		return NULL;