[libvirt] [PATCH] xenconfig: xm: check for driver on disk format

[Jim Fehlig]

On 05/24/2016 04:56 AM, Joao Martins wrote:
> When reviewing libxl vif typename series[0] I found out a bug

s/out//

> on xen-xm formatter where this "virsh domxml-to-native xen-xm file.xml"

s/this//

> can lead to a NULL dereference if the disk driver isn't specified.
> Fix this by checking for driver before writing/testing it down.
>
> [0] https://www.redhat.com/archives/libvir-list/2016-April/msg01434.html
>
> Signed-off-by: Joao Martins <joao.m.martins at oracle.com>
> ---
>  src/xenconfig/xen_xm.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/src/xenconfig/xen_xm.c b/src/xenconfig/xen_xm.c
> index 34d57de..3658c59 100644
> --- a/src/xenconfig/xen_xm.c
> +++ b/src/xenconfig/xen_xm.c
> @@ -297,9 +297,12 @@ xenFormatXMDisk(virConfValuePtr list,
>                  type = "aio";
>              else
>                  type = virStorageFileFormatTypeToString(format);
> -            virBufferAsprintf(&buf, "%s:", driver);
> -            if (STREQ(driver, "tap"))
> -                virBufferAsprintf(&buf, "%s:", type);
> +
> +            if (driver) {
> +                virBufferAsprintf(&buf, "%s:", driver);
> +                if (STREQ(driver, "tap"))
> +                    virBufferAsprintf(&buf, "%s:", type);
> +            }
>          } else {
>              switch (virDomainDiskGetType(disk)) {
>              case VIR_STORAGE_TYPE_FILE:

ACK. I've pushed the patch after the minor commit message tweak. Thanks!

Regards,
Jim