[libvirt] [PATCHv4] python: Avoid memory leaks on libvirt_virNodeGetMemoryStats

Detected by valgrind. Leaks are introduced in commit 17c7795. * python/libvirt-override.c (libvirt_virNodeGetMemoryStats): fix memory leaks and improve codes return value. For details, please see the following link: RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=770944 Signed-off-by: Alex Jia <ajia@redhat.com> --- python/libvirt-override.c | 41 +++++++++++++++++++++++++++++++---------- 1 files changed, 31 insertions(+), 10 deletions(-) diff --git a/python/libvirt-override.c b/python/libvirt-override.c index 792cfa3..634e8bb 100644 --- a/python/libvirt-override.c +++ b/python/libvirt-override.c @@ -2550,7 +2550,9 @@ libvirt_virNodeGetCPUStats(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) static PyObject * libvirt_virNodeGetMemoryStats(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) { - PyObject *ret; + PyObject *ret = NULL; + PyObject *key = NULL; + PyObject *val = NULL; PyObject *pyobj_conn; virConnectPtr conn; unsigned int flags; @@ -2559,7 +2561,7 @@ libvirt_virNodeGetMemoryStats(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) virNodeMemoryStatsPtr stats = NULL; if (!PyArg_ParseTuple(args, (char *)"Oii:virNodeGetMemoryStats", &pyobj_conn, &cellNum, &flags)) - return(NULL); + return ret; conn = (virConnectPtr)(PyvirConnect_Get(pyobj_conn)); LIBVIRT_BEGIN_ALLOW_THREADS; @@ -2570,7 +2572,7 @@ libvirt_virNodeGetMemoryStats(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) if (nparams) { if (VIR_ALLOC_N(stats, nparams) < 0) - return VIR_PY_NONE; + return PyErr_NoMemory(); LIBVIRT_BEGIN_ALLOW_THREADS; c_retval = virNodeGetMemoryStats(conn, cellNum, stats, &nparams, flags); @@ -2580,18 +2582,37 @@ libvirt_virNodeGetMemoryStats(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) return VIR_PY_NONE; } } - if (!(ret = PyDict_New())) { - VIR_FREE(stats); - return VIR_PY_NONE; - } + + if (!(ret = PyDict_New())) + goto error; + for (i = 0; i < nparams; i++) { - PyDict_SetItem(ret, - libvirt_constcharPtrWrap(stats[i].field), - libvirt_ulonglongWrap(stats[i].value)); + key = libvirt_constcharPtrWrap(stats[i].field); + val = libvirt_ulonglongWrap(stats[i].value); + + if (!key || !val) { + ret = NULL; + goto error; + } + + if (PyDict_SetItem(ret, key, val) < 0) { + Py_DECREF(ret); + ret = NULL; + goto error; + } + + Py_DECREF(key); + Py_DECREF(val); } VIR_FREE(stats); return ret; + +error: + VIR_FREE(stats); + Py_XDECREF(key); + Py_XDECREF(val); + return ret; } static PyObject * -- 1.7.1

On 03/20/2012 01:14 AM, Alex Jia wrote:
Detected by valgrind. Leaks are introduced in commit 17c7795.
* python/libvirt-override.c (libvirt_virNodeGetMemoryStats): fix memory leaks and improve codes return value.
For details, please see the following link: RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=770944
Signed-off-by: Alex Jia <ajia@redhat.com> --- python/libvirt-override.c | 41 +++++++++++++++++++++++++++++++---------- 1 files changed, 31 insertions(+), 10 deletions(-)
for (i = 0; i < nparams; i++) { - PyDict_SetItem(ret, - libvirt_constcharPtrWrap(stats[i].field), - libvirt_ulonglongWrap(stats[i].value)); + key = libvirt_constcharPtrWrap(stats[i].field); + val = libvirt_ulonglongWrap(stats[i].value); + + if (!key || !val) { + ret = NULL; + goto error;
Memory leak of ret.
+ } + + if (PyDict_SetItem(ret, key, val) < 0) { + Py_DECREF(ret); + ret = NULL; + goto error; + }
Fix it by doing: if (!key || !val || PyDict_SetItem(ret, key, val) < 0) { Py_DECREF(ret); ret = NULL; goto error; } ACK with that fix. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org

Eric, thanks for your review and comment, I will change patch with your advice then directly push. Alex ----- Original Message ----- From: "Eric Blake" <eblake@redhat.com> To: "Alex Jia" <ajia@redhat.com> Cc: libvir-list@redhat.com Sent: Tuesday, March 20, 2012 11:46:51 PM Subject: Re: [libvirt] [PATCHv4] python: Avoid memory leaks on libvirt_virNodeGetMemoryStats On 03/20/2012 01:14 AM, Alex Jia wrote:
Detected by valgrind. Leaks are introduced in commit 17c7795.
* python/libvirt-override.c (libvirt_virNodeGetMemoryStats): fix memory leaks and improve codes return value.
For details, please see the following link: RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=770944
Signed-off-by: Alex Jia <ajia@redhat.com> --- python/libvirt-override.c | 41 +++++++++++++++++++++++++++++++---------- 1 files changed, 31 insertions(+), 10 deletions(-)
for (i = 0; i < nparams; i++) { - PyDict_SetItem(ret, - libvirt_constcharPtrWrap(stats[i].field), - libvirt_ulonglongWrap(stats[i].value)); + key = libvirt_constcharPtrWrap(stats[i].field); + val = libvirt_ulonglongWrap(stats[i].value); + + if (!key || !val) { + ret = NULL; + goto error;
Memory leak of ret.
+ } + + if (PyDict_SetItem(ret, key, val) < 0) { + Py_DECREF(ret); + ret = NULL; + goto error; + }
Fix it by doing: if (!key || !val || PyDict_SetItem(ret, key, val) < 0) { Py_DECREF(ret); ret = NULL; goto error; } ACK with that fix. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
participants (2)
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Alex Jia
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Eric Blake