From: Phil Sutter <phil@nwl.cc>
Date: Tue, 10 Jan 2023 21:36:58 +0000 (+0100)
Subject: netlink: Fix for potential NULL-pointer deref
X-Git-Tag: v1.0.7~35
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=927d5674e7bf656428f97c54c9171006e8c3c75e;p=thirdparty%2Fnftables.git

netlink: Fix for potential NULL-pointer deref

If memory allocation fails, calloc() returns NULL which was not checked
for. The code seems to expect zero array size though, so simply
replacing this call by one of the x*calloc() ones won't work. So guard
the call also by a check for 'len'.

Fixes: db0697ce7f602 ("src: support for flowtable listing")
Signed-off-by: Phil Sutter <phil@nwl.cc>
---

diff --git a/src/netlink.c b/src/netlink.c
index 51de9c9c..efae1251 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -1790,7 +1790,8 @@ netlink_delinearize_flowtable(struct netlink_ctx *ctx,
 	while (dev_array[len])
 		len++;
 
-	flowtable->dev_array = calloc(1, len * sizeof(char *));
+	if (len)
+		flowtable->dev_array = xmalloc(len * sizeof(char *));
 	for (i = 0; i < len; i++)
 		flowtable->dev_array[i] = xstrdup(dev_array[i]);