[libvirt] [PATCH] Fix cd eject segfault

[Daniel P. Berrange]

On Thu, Aug 21, 2008 at 11:20:28PM -0400, Cole Robinson wrote:
> The cdrom eject code was trying to dereference the
> NULL source of an empty cdrom. Attached patch fixes
> this.
> @@ -2972,6 +2973,13 @@ static int qemudDomainChangeCDROM(virDomainPtr dom,
>          }
>          VIR_FREE(safe_path);
>  
> +        newsrc = strdup(newdisk->src);
> +        if (!newsrc) {
> +            qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
> +                             "%s", _("out of memory"));
> +            return -1;
> +        }

Rather than dup'ing the string here and having to deal with OOM...

> +
>      } else if (asprintf(&cmd, "eject cdrom") == -1) {
>          qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
>                           "%s", _("out of memory"));
> @@ -2982,11 +2990,17 @@ static int qemudDomainChangeCDROM(virDomainPtr dom,
>          qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
>                           "%s", _("cannot change cdrom media"));
>          VIR_FREE(cmd);
> +        VIR_FREE(newsrc);
>          return -1;
>      }
>      VIR_FREE(reply);
>      VIR_FREE(cmd);
> -    strcpy(olddisk->src, newdisk->src);
> +
> +    VIR_FREE(olddisk->src);
> +    if (newsrc) {
> +        olddisk->src = newsrc;
> +        newsrc = NULL;
> +    }

Just do

      VIR_FREE(olddisk->src);
      olddisk->src = newdisk->src;
      newdisk->src = NULL;

Daniel
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