Re: [Qemu-devel] [PATCH v4 29/30] vmxnet3: validate queues configuration coming from quest

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Michael S. Tsirkin (mst@redhat.com) wrote:
> From: Dmitry Fleytman <dmitry@daynix.com>
> 
> CVE-2013-4544
> 
> Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
> Reported-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/net/vmxnet3.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
> index 8c6df05..0fa54e7 100644
> --- a/hw/net/vmxnet3.c
> +++ b/hw/net/vmxnet3.c
> @@ -1336,6 +1336,17 @@ static void vmxnet3_validate_interrupts(VMXNET3State *s)
>      }
>  }
>  
> +static void vmxnet3_validate_queues(VMXNET3State *s)
> +{
> +    if (s->txq_num > VMXNET3_DEVICE_MAX_TX_QUEUES) {
> +        hw_error("Bad TX queues number: %d\n", s->txq_num);
> +    }
> +
> +    if (s->rxq_num > VMXNET3_DEVICE_MAX_RX_QUEUES) {
> +        hw_error("Bad RX queues number: %d\n", s->rxq_num);
> +    }

Why isn't that >= ?
(I agree it matches the original assert).

        Vmxnet3RxqDescr rxq_descr[VMXNET3_DEVICE_MAX_RX_QUEUES];
        Vmxnet3TxqDescr txq_descr[VMXNET3_DEVICE_MAX_TX_QUEUES];

static void vmxnet3_fill_stats(VMXNET3State *s)
{
    int i;
    for (i = 0; i < s->txq_num; i++) {
        cpu_physical_memory_write(s->txq_descr[i].tx_stats_pa,
                                  &s->txq_descr[i].txq_stats,
                                  sizeof(s->txq_descr[i].txq_stats));
    }

so that looks like it's 0 indexed.

Dave

> +}
> +
>  static void vmxnet3_activate_device(VMXNET3State *s)
>  {
>      int i;
> @@ -1382,7 +1393,7 @@ static void vmxnet3_activate_device(VMXNET3State *s)
>          VMXNET3_READ_DRV_SHARED8(s->drv_shmem, devRead.misc.numRxQueues);
>  
>      VMW_CFPRN("Number of TX/RX queues %u/%u", s->txq_num, s->rxq_num);
> -    assert(s->txq_num <= VMXNET3_DEVICE_MAX_TX_QUEUES);
> +    vmxnet3_validate_queues(s);
>  
>      qdescr_table_pa =
>          VMXNET3_READ_DRV_SHARED64(s->drv_shmem, devRead.misc.queueDescPA);
> -- 
> MST
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK