[libvirt] [PATCH] qemuMonitorTextGetMemoryStats: plug a leak on an error path

Coverity complained about a leak via this return -1 in qemu_monitor_text.c: int qemuMonitorTextGetMemoryStats(qemuMonitorPtr mon, virDomainMemoryStatPtr stats, unsigned int nr_stats) { char *reply = NULL; int ret = 0; char *offset; if (qemuMonitorCommand(mon, "info balloon", &reply) < 0) { qemudReportError(NULL, NULL, NULL, VIR_ERR_OPERATION_FAILED, "%s", _("could not query memory balloon statistics")); return -1; } That can happen because qemuMonitorCommand calls qemuMonitorCommandWithFd which calls qemuMonitorCommandWithHandler, which does this: 218 ret = qemuMonitorSend(mon, &msg); ... 228 if (msg.rxBuffer) { 229 *reply = msg.rxBuffer; 230 } else { 231 *reply = strdup(""); 232 if (!*reply) { 233 virReportOOMError(NULL); 234 return -1; 235 } 236 } 237 238 if (ret < 0) 239 virReportSystemError(NULL, msg.lastErrno, 240 _("cannot send monitor command '%s'"), cmd); 241 242 return ret; 243 } That function breaks contract by failing to free *reply when it returns a negative value. Here's the fix: From: Jim Meyering <meyering(a)redhat.com&gt; Date: Wed, 20 Jan 2010 18:24:47 +0100 Subject: [PATCH] qemuMonitorTextGetMemoryStats: plug a leak on an error path * src/qemu/qemu_monitor_text.c (qemuMonitorCommandWithHandler): Always free *reply, upon failure. --- src/qemu/qemu_monitor_text.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_monitor_text.c b/src/qemu/qemu_monitor_text.c index c3848b5..d921c7e 100644 --- a/src/qemu/qemu_monitor_text.c +++ b/src/qemu/qemu_monitor_text.c @@ -1,7 +1,7 @@ /* * qemu_monitor_text.c: interaction with QEMU monitor console * - * Copyright (C) 2006-2009 Red Hat, Inc. + * Copyright (C) 2006-2010 Red Hat, Inc. * Copyright (C) 2006 Daniel P. Berrange * * This library is free software; you can redistribute it and/or @@ -235,9 +235,11 @@ qemuMonitorCommandWithHandler(qemuMonitorPtr mon, } } - if (ret < 0) + if (ret < 0) { virReportSystemError(NULL, msg.lastErrno, _("cannot send monitor command '%s'"), cmd); + VIR_FREE(*reply); + } return ret; } -- 1.6.6.516.gb72f