[libvirt] [PATCHv2] network: Avoid memory leaks on networkBuildDnsmasqArgv

[Eric Blake]

On 01/18/2012 03:04 AM, ajia at redhat.com wrote:
> From: Alex Jia <ajia at redhat.com>
> 
> Detected by valgrind. Leaks introduced in commit 973af236.
> 
> * src/network/bridge_driver.c: fix memory leaks on failure and successful path.
> 
> * How to reproduce?
> % make -C tests check TESTS=networkxml2argvtest
> % cd tests && valgrind -v --leak-check=full ./networkxml2argvtest
> 

>  src/network/bridge_driver.c |    9 ++++++---
>  1 files changed, 6 insertions(+), 3 deletions(-)

Needs a v3.

> 
> diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
> index 5d0d528..5bd5a50 100644
> --- a/src/network/bridge_driver.c
> +++ b/src/network/bridge_driver.c
> @@ -459,6 +459,9 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>      int r, ret = -1;
>      int nbleases = 0;
>      int ii;
> +    char *recordPort = NULL;
> +    char *recordPriority = NULL;
> +    char *recordWeight = NULL;
>      virNetworkIpDefPtr tmpipdef;

Moving the declaration here, and a cleanup at the end, will only free
_one_ instance of allocation.

>  
>      /*
> @@ -530,9 +533,6 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>  
>          for (i = 0; i < dns->nsrvrecords; i++) {
>              char *record = NULL;
> -            char *recordPort = NULL;
> -            char *recordPriority = NULL;
> -            char *recordWeight = NULL;

But these values were allocated in a for loop, so if there is more than
one nsrvrecords, then you are leaking on each iteration of the loop.

>  
>              if (dns->srvrecords[i].service && dns->srvrecords[i].protocol) {
>                  if (dns->srvrecords[i].port) {
> @@ -671,6 +671,9 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>  
>      ret = 0;
>  cleanup:
> +    VIR_FREE(recordPort);
> +    VIR_FREE(recordWeight);
> +    VIR_FREE(recordPriority);

You need to also copy these three lines into the end of the for loop.

-- 
Eric Blake   eblake at redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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