[Qemu-devel] Re: [V3 PATCH] net: properly handle illegal fd/vhostfd from command line

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 25 Oct 2010 13:39:59 +0800
Jason Wang <jasowang@redhat.com> wrote:

> When hanlding fd/vhostfd form command line through net_handle_fd_param(),
> we need to check mon and return value of strtol() otherwise we could
> get segmentation fault or invalid fd when user type an illegal fd/vhostfd.
> 
> This patch is based on the suggestions from
> Luiz Capitulino <lcapitulino@redhat.com>.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>

> ---
>  net.c |   16 +++++++++++-----
>  1 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/net.c b/net.c
> index ed74c7f..c5e6063 100644
> --- a/net.c
> +++ b/net.c
> @@ -774,19 +774,25 @@ int qemu_find_nic_model(NICInfo *nd, const char * const *models,
>  
>  int net_handle_fd_param(Monitor *mon, const char *param)
>  {
> -    if (!qemu_isdigit(param[0])) {
> -        int fd;
> +    int fd;
> +
> +    if (!qemu_isdigit(param[0]) && mon) {
>  
>          fd = monitor_get_fd(mon, param);
>          if (fd == -1) {
>              error_report("No file descriptor named %s found", param);
>              return -1;
>          }
> -
> -        return fd;
>      } else {
> -        return strtol(param, NULL, 0);
> +        char *endptr = NULL;
> +
> +        fd = strtol(param, &endptr, 10);
> +        if (*endptr || (fd == 0 && param == endptr)) {
> +            return -1;
> +        }
>      }
> +
> +    return fd;
>  }
>  
>  static int net_init_nic(QemuOpts *opts,
>