[libvirt] [PATCH] Fix QEMU migration cookie crash for guests with no graphics

[Wen Congyang]

At 05/19/2011 01:08 AM, Daniel P. Berrange Write:
> When generating a cookie for a guest with no data, the
> QEMU_MIGRATION_COOKIE_GRAPHICS flag was set even if no
> graphics data was added. Avoid setting the flag unless
> it was needed, also add a safety check for mig->graphics
> being non-NULL
> 
> * src/qemu/qemu_migration.c: Avoid cookie crash for guest
>   with no graphics
> ---
>  src/qemu/qemu_migration.c |   14 ++++++++------
>  1 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index fcf8f9c..4d7bc38 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -252,11 +252,12 @@ qemuMigrationCookieAddGraphics(qemuMigrationCookiePtr mig,
>  
>      if (dom->def->ngraphics == 1 &&
>          (dom->def->graphics[0]->type == VIR_DOMAIN_GRAPHICS_TYPE_VNC ||
> -         dom->def->graphics[0]->type == VIR_DOMAIN_GRAPHICS_TYPE_SPICE) &&
> -        !(mig->graphics = qemuMigrationCookieGraphicsAlloc(driver, dom->def->graphics[0])))
> -        return -1;
> -
> -    mig->flags |= QEMU_MIGRATION_COOKIE_GRAPHICS;
> +         dom->def->graphics[0]->type == VIR_DOMAIN_GRAPHICS_TYPE_SPICE)) {
> +        if (!(mig->graphics =
> +              qemuMigrationCookieGraphicsAlloc(driver, dom->def->graphics[0])))
> +            return -1;
> +        mig->flags |= QEMU_MIGRATION_COOKIE_GRAPHICS;
> +    }
>  
>      return 0;
>  }
> @@ -295,7 +296,8 @@ static void qemuMigrationCookieXMLFormat(virBufferPtr buf,
>      virBufferEscapeString(buf, "  <hostname>%s</hostname>\n", mig->hostname);
>      virBufferAsprintf(buf, "  <hostuuid>%s</hostuuid>\n", hostuuidstr);
>  
> -    if (mig->flags & QEMU_MIGRATION_COOKIE_GRAPHICS)
> +    if ((mig->flags & QEMU_MIGRATION_COOKIE_GRAPHICS) &&
> +        mig->graphics)
>          qemuMigrationCookieGraphicsXMLFormat(buf, mig->graphics);
>  
>      virBufferAddLit(buf, "</qemu-migration>\n");

This duplicates my patch:

https://www.redhat.com/archives/libvir-list/2011-May/msg01095.html