[libvirt] [PATCHv3 15/17] util: eliminate leak in ebtables

[Laine Stump]

When ebtRulesAppend failed its realloc, it was free'ing the argv it
had been send, but not the rules. The caller also didn't free the
rules.

This is kind of a lost cause, since it's a leak that only occurs after
a failure to allocate memory, but the fix also gives the ebtRuleFree
function a more accurate name (ebtRuleClear), and I was making a
change to this code anyway, so I split out the bugfix for easy review.
---
 src/util/ebtables.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/src/util/ebtables.c b/src/util/ebtables.c
index f1b2986..d3a8432 100644
--- a/src/util/ebtables.c
+++ b/src/util/ebtables.c
@@ -94,7 +94,7 @@ enum {
 };
 
 static void
-ebtRuleFree(ebtRule *rule)
+ebtRuleClear(ebtRule *rule)
 {
     VIR_FREE(rule->rule);
 
@@ -112,20 +112,13 @@ ebtRulesAppend(ebtRules *rules,
                const char **argv,
                int command_idx)
 {
+    ebtRule tmp = { .rule = rule, .argv = argv, .command_idx = command_idx };
+
     if (VIR_REALLOC_N(rules->rules, rules->nrules+1) < 0) {
-        int i = 0;
-        while (argv[i])
-            VIR_FREE(argv[i++]);
-        VIR_FREE(argv);
+        ebtRuleClear(&tmp);
         return ENOMEM;
     }
-
-    rules->rules[rules->nrules].rule        = rule;
-    rules->rules[rules->nrules].argv        = argv;
-    rules->rules[rules->nrules].command_idx = command_idx;
-
-    rules->nrules++;
-
+    rules->rules[rules->nrules++] = tmp;
     return 0;
 }
 
@@ -142,7 +135,7 @@ ebtRulesRemove(ebtRules *rules,
     if (i >= rules->nrules)
         return EINVAL;
 
-    ebtRuleFree(&rules->rules[i]);
+    ebtRuleClear(&rules->rules[i]);
 
     memmove(&rules->rules[i],
             &rules->rules[i+1],
@@ -163,7 +156,7 @@ ebtRulesFree(ebtRules *rules)
 
     if (rules->rules) {
         for (i = 0; i < rules->nrules; i++)
-            ebtRuleFree(&rules->rules[i]);
+            ebtRuleClear(&rules->rules[i]);
 
         VIR_FREE(rules->rules);
 
-- 
1.7.11.7