Re: [Libvir] [patch 1/5] iptables: fix invalid free
On Wed, Mar 21, 2007 at 12:47:58PM +0000, Mark McLoughlin wrote:
In iptablesContextNew(), make sure we don't try and free an
invalid
pointer if one of the iptRulesNew() fails.
Signed-off-by: Mark McLoughlin <markmc(a)redhat.com>
Index: libvirt/qemud/iptables.c
===================================================================
--- libvirt.orig/qemud/iptables.c
+++ libvirt/qemud/iptables.c
@@ -496,7 +496,7 @@ iptablesContextNew(void)
{
iptablesContext *ctx;
- if (!(ctx = (iptablesContext *) malloc(sizeof (iptablesContext))))
+ if (!(ctx = (iptablesContext *) calloc(1, sizeof (iptablesContext))))
return NULL;
if (!(ctx->input_filter = iptRulesNew("filter", IPTABLES_PREFIX
"INPUT")))
I usually prefer malloc + memset( , 0, ) , but this probably comes from
libxml2 where I replaced malloc calls with specific wrappers (and I still
have a TODO for this in libvirt though some part of libvirt are not linked to
libxml2 I guess so that may make things a bit harder)
What's the policy w.r.t. error reporting in qemud and libvirt related daemons
in general ? I guess a failure to malloc or thisd kind of problems should be
logged somewhere, right ?
@@ -518,9 +518,12 @@ iptablesContextNew(void)
void
iptablesContextFree(iptablesContext *ctx)
{
- iptRulesFree(ctx->input_filter);
- iptRulesFree(ctx->forward_filter);
- iptRulesFree(ctx->nat_postrouting);
+ if (ctx->input_filter)
+ iptRulesFree(ctx->input_filter);
+ if (ctx->forward_filter)
+ iptRulesFree(ctx->forward_filter);
+ if (ctx->nat_postrouting)
+ iptRulesFree(ctx->nat_postrouting);
free(ctx);
}
The patch does the right thing, sounds good to me :-)
Daniel
--
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Daniel Veillard | virtualization library http://libvirt.org/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
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