Re: [Qemu-devel] [PATCHv2] filter-mirror: segfault when specifying non existent device

[Zhang Chen]

2017-09-29 12:03 GMT+00:00 Eduardo Otubo <address@hidden>:

> v2:
>     Removed "err:" label from the end of the function and replaced by
>     two separate error messages. One when outdev is not specified and
>     one when outdev does not exist.
>
>     Fixed the error message that was referencing nf->netdev_id and not
>     s->outdev.
>
> When using filter-mirror like the example below where the interface
> 'ndev0' does not exist on the host, QEMU crashes into segmentation
> fault.
>
>  $ qemu-system-x86_64 -S -machine pc -netdev user,id=ndev0 -object
> filter-mirror,id=test-object,netdev=ndev0
>
> This happens because the function filter_mirror_setup() does not checks
> if the device actually exists and still keep on processing calling
> qemu_chr_find(). This patch fixes this issue.
>
> Signed-off-by: Eduardo Otubo <address@hidden>
>


 Reviewed-by: Zhang Chen <address@hidden>

 Thanks
 Zhang Chen


> ---
>  net/filter-mirror.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> index 90e2c92337..ce0dc23c2a 100644
> --- a/net/filter-mirror.c
> +++ b/net/filter-mirror.c
> @@ -213,6 +213,12 @@ static void filter_mirror_setup(NetFilterState *nf,
> Error **errp)
>      MirrorState *s = FILTER_MIRROR(nf);
>      Chardev *chr;
>
> +    if (s->outdev == NULL) {
> +        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, "filter-mirror
> parameter"\
> +                  " 'outdev' cannot be empty");
> +        return;
> +    }
> +
>      chr = qemu_chr_find(s->outdev);
>      if (chr == NULL) {
>          error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
> --
> 2.13.5
>
>
>