The virSocketAddrFormat() allocates the string and it's caller responsibility to free it afterwards. ==28857== 11 bytes in 1 blocks are definitely lost in loss record 37 of 168 ==28857== at 0x4C2BEDF: malloc (vg_replace_malloc.c:299) ==28857== by 0x9A81D79: strdup (in /lib64/libc-2.23.so) ==28857== by 0x5DA3BF0: virStrdup (virstring.c:902) ==28857== by 0x5D96182: virSocketAddrFormatFull (virsocketaddr.c:427) ==28857== by 0x5D95E13: virSocketAddrFormat (virsocketaddr.c:352) ==28857== by 0x5706890: qemuBuildHostNetStr (qemu_command.c:3891) ==28857== by 0x57138D3: qemuBuildInterfaceCommandLine (qemu_command.c:8597) ==28857== by 0x5713D6A: qemuBuildNetCommandLine (qemu_command.c:8699) ==28857== by 0x57176F6: qemuBuildCommandLine (qemu_command.c:10027) ==28857== by 0x5769D61: qemuProcessCreatePretendCmd (qemu_process.c:6004) ==28857== by 0x4056EC: testCompareXMLToArgv (qemuxml2argvtest.c:502) ==28857== by 0x41DF40: virTestRun (testutils.c:180) Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_command.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 9b3e3fc04..abeb24846 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3900,6 +3900,7 @@ qemuBuildHostNetStr(virDomainNetDefPtr net, if (ip->prefix) virBufferAsprintf(&buf, "/%u", ip->prefix); virBufferAddChar(&buf, ','); + VIR_FREE(addr); } break;