[libvirt] [PATCHv3] Fix Memory Leak in virQEMUCapsInitGuestFromBinary()

While running qemucaps2xmltest, it was found that valgrind pointed out the following memory leaks: ==29896== 0 bytes in 1 blocks are definitely lost in loss record 1 of 65 ==29896== at 0x4A0577B: calloc (vg_replace_malloc.c:593) ==29896== by 0x4C6B45E: virAllocN (viralloc.c:191) ==29896== by 0x4232A9: virQEMUCapsGetMachineTypesCaps (qemu_capabilities.c:1999) ==29896== by 0x4234E7: virQEMUCapsInitGuestFromBinary (qemu_capabilities.c:789) ==29896== by 0x41F10B: testQemuCapsXML (qemucaps2xmltest.c:118) ==29896== by 0x41FFD1: virtTestRun (testutils.c:201) ==29896== by 0x41EE7A: mymain (qemucaps2xmltest.c:203) ==29896== by 0x42074D: virtTestMain (testutils.c:789) ==29896== by 0x3E6CE1ED1C: (below main) (libc-start.c:226) ==29896== ==29896== 0 bytes in 1 blocks are definitely lost in loss record 2 of 65 ==29896== at 0x4A0577B: calloc (vg_replace_malloc.c:593) ==29896== by 0x4C6B45E: virAllocN (viralloc.c:191) ==29896== by 0x4232A9: virQEMUCapsGetMachineTypesCaps (qemu_capabilities.c:1999) ==29896== by 0x4234E7: virQEMUCapsInitGuestFromBinary (qemu_capabilities.c:789) ==29896== by 0x41F10B: testQemuCapsXML (qemucaps2xmltest.c:118) ==29896== by 0x41FFD1: virtTestRun (testutils.c:201) ==29896== by 0x41EEA3: mymain (qemucaps2xmltest.c:204) ==29896== by 0x42074D: virtTestMain (testutils.c:789) ==29896== by 0x3E6CE1ED1C: (below main) (libc-start.c:226) --- Based on Daniel's comments. v2: https://www.redhat.com/archives/libvir-list/2014-March/msg01672.html v1: https://www.redhat.com/archives/libvir-list/2014-March/msg01667.html src/qemu/qemu_capabilities.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 7673592..e4c1cbd 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -1996,10 +1996,12 @@ int virQEMUCapsGetMachineTypesCaps(virQEMUCapsPtr qemuCaps, *nmachines = 0; *machines = NULL; - if (VIR_ALLOC_N(*machines, qemuCaps->nmachineTypes) < 0) - goto error; *nmachines = qemuCaps->nmachineTypes; + if (*nmachines && + VIR_ALLOC_N(*machines, qemuCaps->nmachineTypes) < 0) + goto error; + for (i = 0; i < qemuCaps->nmachineTypes; i++) { virCapsGuestMachinePtr mach; if (VIR_ALLOC(mach) < 0) -- 1.7.1