[ANNOUNCE] Release of iptables-1.3.2

Marcus Sundberg marcus at ingate.com
Sat Jul 16 14:58:45 CEST 2005


Netfilter Core Team wrote:
> - Release previously merged options from merge_opts(), reduces memory-usage of
>   ipt ables-restore dramatically 

Hi,

the call to free_opts() in merge_options() is invalid C. The oldopts
argument always refers to the memory pointed to by the opts global,
which may be freed by the call to free_opts(), but oldopts is used
after the free_opts() call. This patch makes sure we don't use freed
memory.

//Marcus

--- iptables.c	2005/07/16 12:52:33
+++ iptables.c	2005/07/16 12:52:45
@@ -1028,9 +1028,6 @@ merge_options(struct option *oldopts, co
 	unsigned int num_old, num_new, i;
 	struct option *merge;

-	/* Release previous options merged if any */
-	free_opts(0);
-	
 	for (num_old = 0; oldopts[num_old].name; num_old++);
 	for (num_new = 0; newopts[num_new].name; num_new++);

@@ -1039,6 +1036,7 @@ merge_options(struct option *oldopts, co

 	merge = malloc(sizeof(struct option) * (num_new + num_old + 1));
 	memcpy(merge, oldopts, num_old * sizeof(struct option));
+	free_opts(0); /* Release previous options merged if any */
 	for (i = 0; i < num_new; i++) {
 		merge[num_old + i] = newopts[i];
 		merge[num_old + i].val += *option_offset;


-- 
---------------------------------------+--------------------------
  Marcus Sundberg <marcus at ingate.com>  | Firewalls with SIP & NAT
 Software Developer, Ingate Systems AB |  http://www.ingate.com/



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