[libvirt] [PATCH] qemu: Check for negative port values in network drive configuration

[Eric Blake]

On 02/19/2015 08:53 AM, Erik Skultety wrote:
> We interpret port values as signed int (convert them from char *),
> so if a negative value is provided in network disk's configuration,
> we accept it as valid, however there's an 'unknown cause' error raised later.
> This error is only accidental because we return the port value in the return code.
> This patch adds just a minor tweak to the already existing check so we
> reject negative values the same way as we reject non-numerical strings.
> 
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1163553
> ---
>  src/qemu/qemu_command.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index 743d6f0..c1e9559 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -2954,7 +2954,7 @@ qemuNetworkDriveGetPort(int protocol,
>      int ret = 0;
>  
>      if (port) {
> -        if (virStrToLong_i(port, NULL, 10, &ret) < 0) {
> +        if (virStrToLong_i(port, NULL, 10, &ret) < 0 || ret < 0) {
>              virReportError(VIR_ERR_INTERNAL_ERROR,
>                             _("failed to parse port number '%s'"),
>                             port);

Won't this still allow wraparound (an extremely large negative input
that gets parsed as positive)?  Wouldn't it be better to switch to
virStrToLong_uip to force a positive number parse?

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

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