[libvirt] [PATCHv3] network: Avoid memory leaks on networkBuildDnsmasqArgv

[ajia at redhat.com]

From: Alex Jia <ajia at redhat.com>

Detected by valgrind. Leaks introduced in commit 973af236.

* src/network/bridge_driver.c: fix memory leaks on failure and successful path.

* How to reproduce?
% make -C tests check TESTS=networkxml2argvtest
% cd tests && valgrind -v --leak-check=full ./networkxml2argvtest

* Actual result:

==2226== 3 bytes in 1 blocks are definitely lost in loss record 1 of 24
==2226==    at 0x4A05FDE: malloc (vg_replace_malloc.c:236)
==2226==    by 0x39CF0FEDE7: __vasprintf_chk (in /lib64/libc-2.12.so)
==2226==    by 0x41DFF7: virVasprintf (stdio2.h:199)
==2226==    by 0x41E0B7: virAsprintf (util.c:1695)
==2226==    by 0x41A2D9: networkBuildDhcpDaemonCommandLine (bridge_driver.c:545)
==2226==    by 0x4145C8: testCompareXMLToArgvHelper (networkxml2argvtest.c:47)
==2226==    by 0x4156A1: virtTestRun (testutils.c:141)
==2226==    by 0x414332: mymain (networkxml2argvtest.c:123)
==2226==    by 0x414D97: virtTestMain (testutils.c:696)
==2226==    by 0x39CF01ECDC: (below main) (in /lib64/libc-2.12.so)
==2226==
==2226== 3 bytes in 1 blocks are definitely lost in loss record 2 of 24
==2226==    at 0x4A05FDE: malloc (vg_replace_malloc.c:236)
==2226==    by 0x39CF0FEDE7: __vasprintf_chk (in /lib64/libc-2.12.so)
==2226==    by 0x41DFF7: virVasprintf (stdio2.h:199)
==2226==    by 0x41E0B7: virAsprintf (util.c:1695)
==2226==    by 0x41A307: networkBuildDhcpDaemonCommandLine (bridge_driver.c:551)
==2226==    by 0x4145C8: testCompareXMLToArgvHelper (networkxml2argvtest.c:47)
==2226==    by 0x4156A1: virtTestRun (testutils.c:141)
==2226==    by 0x414332: mymain (networkxml2argvtest.c:123)
==2226==    by 0x414D97: virtTestMain (testutils.c:696)
==2226==    by 0x39CF01ECDC: (below main) (in /lib64/libc-2.12.so)
==2226==
==2226== 5 bytes in 1 blocks are definitely lost in loss record 4 of 24
==2226==    at 0x4A05FDE: malloc (vg_replace_malloc.c:236)
==2226==    by 0x39CF0FEDE7: __vasprintf_chk (in /lib64/libc-2.12.so)
==2226==    by 0x41DFF7: virVasprintf (stdio2.h:199)
==2226==    by 0x41E0B7: virAsprintf (util.c:1695)
==2226==    by 0x41A2AB: networkBuildDhcpDaemonCommandLine (bridge_driver.c:539)
==2226==    by 0x4145C8: testCompareXMLToArgvHelper (networkxml2argvtest.c:47)
==2226==    by 0x4156A1: virtTestRun (testutils.c:141)
==2226==    by 0x414332: mymain (networkxml2argvtest.c:123)
==2226==    by 0x414D97: virtTestMain (testutils.c:696)
==2226==    by 0x39CF01ECDC: (below main) (in /lib64/libc-2.12.so)
==2226==
==2226== LEAK SUMMARY:
==2226==    definitely lost: 11 bytes in 3 blocks


Signed-off-by: Alex Jia <ajia at redhat.com>
---
 src/network/bridge_driver.c |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 5d0d528..c9a8ccf 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -458,7 +458,10 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
 {
     int r, ret = -1;
     int nbleases = 0;
-    int ii;
+    int ii, i, j;
+    char *recordPort = NULL;
+    char *recordPriority = NULL;
+    char *recordWeight = NULL;
     virNetworkIpDefPtr tmpipdef;
 
     /*
@@ -513,7 +516,6 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
 
     if (network->def->dns != NULL) {
         virNetworkDNSDefPtr dns = network->def->dns;
-        int i;
 
         for (i = 0; i < dns->ntxtrecords; i++) {
             char *record = NULL;
@@ -530,10 +532,6 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
 
         for (i = 0; i < dns->nsrvrecords; i++) {
             char *record = NULL;
-            char *recordPort = NULL;
-            char *recordPriority = NULL;
-            char *recordWeight = NULL;
-
             if (dns->srvrecords[i].service && dns->srvrecords[i].protocol) {
                 if (dns->srvrecords[i].port) {
                     if (virAsprintf(&recordPort, "%d", dns->srvrecords[i].port) < 0) {
@@ -671,6 +669,11 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
 
     ret = 0;
 cleanup:
+    for (j = 0; j < i; j++) {
+        VIR_FREE(recordPort);
+        VIR_FREE(recordWeight);
+        VIR_FREE(recordPriority);
+    }
     return ret;
 }
 
-- 
1.7.1