Re: [PATCH] virtio-net: fix map leaking on error during receive

[Michael S. Tsirkin]

On Tue, Mar 08, 2022 at 01:56:42PM +0800, Jason Wang wrote:
> Commit bedd7e93d0196 ("virtio-net: fix use after unmap/free for sg")
> tries to fix the use after free of the sg by caching the virtqueue
> elements in an array and unmap them at once after receiving the
> packets, But it forgot to unmap the cached elements on error which
> will lead to leaking of mapping and other unexpected results.
> 
> Fixing this by detaching the cached elements on error. This addresses
> CVE-2022-26353.


Pls use a tag:

Fixes: CVE-2022-26353


Besides that

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Feel free to merge.

> Reported-by: Victor Tom <vv474172261@gmail.com>
> Cc: qemu-stable@nongnu.org
> Fixes: bedd7e93d0196 ("virtio-net: fix use after unmap/free for sg")
> Signed-off-by: Jason Wang <jasowang@redhat.com>

> ---
>  hw/net/virtio-net.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index cf8ab0f8af..65b61c836c 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -1867,6 +1867,7 @@ static ssize_t virtio_net_receive_rcu(NetClientState 
> *nc, const uint8_t *buf,
>  
>  err:
>      for (j = 0; j < i; j++) {
> +        virtqueue_detach_element(q->rx_vq, elems[j], lens[j]);
>          g_free(elems[j]);
>      }
>  
> -- 
> 2.25.1