[libvirt] [PATCH] Fix memory leak in virCommandRun()

[Eric Blake]

On 12/07/2010 11:10 PM, Hu Tao wrote:
> ---
>  src/util/command.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/src/util/command.c b/src/util/command.c
> index c0520ec..473d1fc 100644
> --- a/src/util/command.c
> +++ b/src/util/command.c
> @@ -956,6 +956,8 @@ virCommandRun(virCommandPtr cmd, int *exitstatus)
>          cmd->errbuf = NULL;
>      }
>  
> +    VIR_FREE(outbuf);
> +    VIR_FREE(errbuf);

Good catch, but not quite right.  I inadvertently disabled logging
abilities with commit ee11729d7, and in so doing, outbuf and errbuf were
never populated because virCommandProcessIO was skipped.  Here's a
better patch:

From 9ce936ee395e967551e36598ff0650315ac7686e Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake at redhat.com>
Date: Wed, 8 Dec 2010 08:03:29 -0700
Subject: [PATCH] command: avoid memory leak

* src/util/command.c (virCommandRun): Fix yesterday's regression
on logging, and avoid leaking log-only output captures.
Reported by Hu Tao.
---
 src/util/command.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/src/util/command.c b/src/util/command.c
index e39e949..089e0bd 100644
--- a/src/util/command.c
+++ b/src/util/command.c
@@ -964,10 +964,12 @@ virCommandRun(virCommandPtr cmd, int *exitstatus)
     if (!cmd->outfdptr) {
         cmd->outfdptr = &cmd->outfd;
         cmd->outbuf = &outbuf;
+        string_io = true;
     }
     if (!cmd->errfdptr) {
         cmd->errfdptr = &cmd->errfd;
         cmd->errbuf = &errbuf;
+        string_io = true;
     }

     if (virCommandRunAsync(cmd, NULL) < 0) {
@@ -1009,6 +1011,7 @@ virCommandRun(virCommandPtr cmd, int *exitstatus)
             VIR_DEBUG("ignoring failed close on fd %d", tmpfd);
         cmd->outfdptr = NULL;
         cmd->outbuf = NULL;
+        VIR_FREE(outbuf);
     }
     if (cmd->errbuf == &errbuf) {
         int tmpfd = cmd->errfd;
@@ -1016,6 +1019,7 @@ virCommandRun(virCommandPtr cmd, int *exitstatus)
             VIR_DEBUG("ignoring failed close on fd %d", tmpfd);
         cmd->errfdptr = NULL;
         cmd->errbuf = NULL;
+        VIR_FREE(errbuf);
     }

     return ret;
-- 
1.7.3.2



-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org

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