[libvirt] [PATCHv3] network: Avoid memory leaks on networkBuildDnsmasqArgv
From: Alex Jia <ajia@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@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
On 29.01.2012 06:24, ajia@redhat.com wrote:
From: Alex Jia <ajia@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@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; }
I think we need v4; You want to free memory in the very same loop where it is allocated. Otherwise we still leak memory from previous loop iterations. More detailed, virAsprintf() takes given pointer and overwrites it. So if pointer was referring to an allocated memory, we lost this single reference and thus leak. Michal
Hi Michal, Thanks for your comment, the following v1 patch should be a right way? https://www.redhat.com/archives/libvir-list/2012-January/msg00209.html Regards, Alex ----- Original Message ----- From: "Michal Privoznik" <mprivozn@redhat.com> To: ajia@redhat.com Cc: libvir-list@redhat.com Sent: Monday, January 30, 2012 7:32:59 PM Subject: Re: [libvirt] [PATCHv3] network: Avoid memory leaks on networkBuildDnsmasqArgv On 29.01.2012 06:24, ajia@redhat.com wrote:
From: Alex Jia <ajia@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@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; }
I think we need v4; You want to free memory in the very same loop where it is allocated. Otherwise we still leak memory from previous loop iterations. More detailed, virAsprintf() takes given pointer and overwrites it. So if pointer was referring to an allocated memory, we lost this single reference and thus leak. Michal
[reordering - top-posting is hard to follow] On 01/30/2012 08:11 AM, Alex Jia wrote:
@@ -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,
I think we need v4; You want to free memory in the very same loop where it is allocated. Otherwise we still leak memory from previous loop iterations. More detailed, virAsprintf() takes given pointer and overwrites it. So if pointer was referring to an allocated memory, we lost this single reference and thus leak.
Michal
Hi Michal, Thanks for your comment, the following v1 patch should be a right way? https://www.redhat.com/archives/libvir-list/2012-January/msg00209.html
v1 was incomplete, but was at least attempting to free things in the for loop where they were allocated. What I'd suggest is: declare variables outside the loop, start the for loop by freeing any state from previous iterations, and also free all state in the cleanup label at which point, you _don't_ have to follow the v1 approach of trying to free variables before every goto or break (and missing some). Something like: char *record = NULL; for (i = 0; i < dns->nsrrvrecords; i++) { /* free previous iteration */ VIR_FREE(record); ... record = ... if (error) goto cleanup; } cleanup: VIR_FREE(record); -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
On 01/31/2012 05:34 AM, Eric Blake wrote:
[reordering - top-posting is hard to follow]
On 01/30/2012 08:11 AM, Alex Jia wrote:
@@ -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, I think we need v4; You want to free memory in the very same loop where it is allocated. Otherwise we still leak memory from previous loop iterations. More detailed, virAsprintf() takes given pointer and overwrites it. So if pointer was referring to an allocated memory, we lost this single reference and thus leak.
Michal Hi Michal, Thanks for your comment, the following v1 patch should be a right way? https://www.redhat.com/archives/libvir-list/2012-January/msg00209.html v1 was incomplete, but was at least attempting to free things in the for loop where they were allocated.
What I'd suggest is:
declare variables outside the loop, start the for loop by freeing any state from previous iterations, and also free all state in the cleanup label
at which point, you _don't_ have to follow the v1 approach of trying to free variables before every goto or break (and missing some). Something like:
char *record = NULL; for (i = 0; i< dns->nsrrvrecords; i++) { /* free previous iteration */ VIR_FREE(record); Hi Eric, thanks for your nice comment, the 'record' variable is allocated memory in previous for loop, but we free it in here, the issue is 'dns->ntxtrecords' = 'dns->nsrrvrecord' ? if not, is it also okay?
Thanks & Regards, Alex
... record = ... if (error) goto cleanup; } cleanup: VIR_FREE(record);
On 01/31/2012 12:15 AM, Alex Jia wrote:
What I'd suggest is:
declare variables outside the loop, start the for loop by freeing any state from previous iterations, and also free all state in the cleanup label
at which point, you _don't_ have to follow the v1 approach of trying to free variables before every goto or break (and missing some). Something like:
char *record = NULL; for (i = 0; i< dns->nsrrvrecords; i++) { /* free previous iteration */ VIR_FREE(record); Hi Eric, thanks for your nice comment, the 'record' variable is allocated memory in previous for loop, but we free it in here, the issue is 'dns->ntxtrecords' = 'dns->nsrrvrecord' ? if not, is it also okay?
That's why you _also_ free things in the cleanup label. If every iteration of the loop frees the previous iteration, then the first iteration of the loop is a no-op, and the cleanup code frees the last iteration, no matter whether you get to the cleanup code via a goto or whether the last iteration exited normally. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
participants (4)
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ajia＠redhat.com -
Alex Jia
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Eric Blake -
Michal Privoznik