Re: [Qemu-devel] [PATCH] e1000: bounds packet size against buffer size

[Stefano Stabellini]

On Mon, 23 Jan 2012, Anthony Liguori wrote:
> Otherwise we can write beyond the buffer and corrupt memory.  This is tracked
> as CVE-2012-0029.

The stable-1.0 branch looks vulnerable too, shouldn't this patch be
backported?


> Signed-off-by: Anthony Liguori <address@hidden>
> ---
>  hw/e1000.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/e1000.c b/hw/e1000.c
> index a29c944..86c5416 100644
> --- a/hw/e1000.c
> +++ b/hw/e1000.c
> @@ -466,6 +466,8 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp)
>              bytes = split_size;
>              if (tp->size + bytes > msh)
>                  bytes = msh - tp->size;
> +
> +            bytes = MIN(sizeof(tp->data) - tp->size, bytes);
>              pci_dma_read(&s->dev, addr, tp->data + tp->size, bytes);
>              if ((sz = tp->size + bytes) >= hdr && tp->size < hdr)
>                  memmove(tp->header, tp->data, hdr);
> @@ -481,6 +483,7 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp)
>          // context descriptor TSE is not set, while data descriptor TSE is 
> set
>          DBGOUT(TXERR, "TCP segmentaion Error\n");
>      } else {
> +        split_size = MIN(sizeof(tp->data) - tp->size, split_size);
>          pci_dma_read(&s->dev, addr, tp->data + tp->size, split_size);
>          tp->size += split_size;
>      }
> -- 
> 1.7.4.1
> 
>