Re: [PATCH v7] net: tulip: check frame size and r/w data length

[Jason Wang <jasowang@redhat.com>]

On 2020/3/26 下午7:11, Li Qiang wrote:
>
>
> P J P <ppandit@redhat.com <mailto:ppandit@redhat.com>> 于2020年3月25日周三 
> 上午1:31写道：
>
>     From: Prasad J Pandit <pjp@fedoraproject.org
>     <mailto:pjp@fedoraproject.org>>
>
>     Tulip network driver while copying tx/rx buffers does not check
>     frame size against r/w data length. This may lead to OOB buffer
>     access. Add check to avoid it.
>
>     Limit iterations over descriptors to avoid potential infinite
>     loop issue in tulip_xmit_list_update.
>
>     Reported-by: Li Qiang <pangpei.lq@antfin.com
>     <mailto:pangpei.lq@antfin.com>>
>     Reported-by: Ziming Zhang <ezrakiez@gmail.com
>     <mailto:ezrakiez@gmail.com>>
>     Reported-by: Jason Wang <jasowang@redhat.com
>     <mailto:jasowang@redhat.com>>
>     Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org
>     <mailto:pjp@fedoraproject.org>>
>
>
>
> Tested-by: Li Qiang <liq3ea@gmail.com <mailto:liq3ea@gmail.com>>
> Reviewed-by: Li Qiang <liq3ea@gmail.com <mailto:liq3ea@gmail.com>>
>
> Thanks,
> Li Qiang


Applied.

Thanks


>
>     ---
>      hw/net/tulip.c | 36 +++++++++++++++++++++++++++---------
>      1 file changed, 27 insertions(+), 9 deletions(-)
>
>     Update v7: fix length check expression to replace '>=' with '>'
>       ->
>     https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg07160.html
>
>     diff --git a/hw/net/tulip.c b/hw/net/tulip.c
>     index cfac2719d3..1295f51d07 100644
>     --- a/hw/net/tulip.c
>     +++ b/hw/net/tulip.c
>     @@ -170,6 +170,10 @@ static void tulip_copy_rx_bytes(TULIPState
>     *s, struct tulip_descriptor *desc)
>              } else {
>                  len = s->rx_frame_len;
>              }
>     +
>     +        if (s->rx_frame_len + len > sizeof(s->rx_frame)) {
>     +            return;
>     +        }
>              pci_dma_write(&s->dev, desc->buf_addr1, s->rx_frame +
>                  (s->rx_frame_size - s->rx_frame_len), len);
>              s->rx_frame_len -= len;
>     @@ -181,6 +185,10 @@ static void tulip_copy_rx_bytes(TULIPState
>     *s, struct tulip_descriptor *desc)
>              } else {
>                  len = s->rx_frame_len;
>              }
>     +
>     +        if (s->rx_frame_len + len > sizeof(s->rx_frame)) {
>     +            return;
>     +        }
>              pci_dma_write(&s->dev, desc->buf_addr2, s->rx_frame +
>                  (s->rx_frame_size - s->rx_frame_len), len);
>              s->rx_frame_len -= len;
>     @@ -227,7 +235,8 @@ static ssize_t tulip_receive(TULIPState *s,
>     const uint8_t *buf, size_t size)
>
>          trace_tulip_receive(buf, size);
>
>     -    if (size < 14 || size > 2048 || s->rx_frame_len ||
>     tulip_rx_stopped(s)) {
>     +    if (size < 14 || size > sizeof(s->rx_frame) - 4
>     +        || s->rx_frame_len || tulip_rx_stopped(s)) {
>              return 0;
>          }
>
>     @@ -275,7 +284,6 @@ static ssize_t tulip_receive_nc(NetClientState
>     *nc,
>          return tulip_receive(qemu_get_nic_opaque(nc), buf, size);
>      }
>
>     -
>      static NetClientInfo net_tulip_info = {
>          .type = NET_CLIENT_DRIVER_NIC,
>          .size = sizeof(NICState),
>     @@ -558,7 +566,7 @@ static void tulip_tx(TULIPState *s, struct
>     tulip_descriptor *desc)
>              if ((s->csr[6] >> CSR6_OM_SHIFT) & CSR6_OM_MASK) {
>                  /* Internal or external Loopback */
>                  tulip_receive(s, s->tx_frame, s->tx_frame_len);
>     -        } else {
>     +        } else if (s->tx_frame_len <= sizeof(s->tx_frame)) {
>                  qemu_send_packet(qemu_get_queue(s->nic),
>                      s->tx_frame, s->tx_frame_len);
>              }
>     @@ -570,23 +578,31 @@ static void tulip_tx(TULIPState *s, struct
>     tulip_descriptor *desc)
>          }
>      }
>
>     -static void tulip_copy_tx_buffers(TULIPState *s, struct
>     tulip_descriptor *desc)
>     +static int tulip_copy_tx_buffers(TULIPState *s, struct
>     tulip_descriptor *desc)
>      {
>          int len1 = (desc->control >> TDES1_BUF1_SIZE_SHIFT) &
>     TDES1_BUF1_SIZE_MASK;
>          int len2 = (desc->control >> TDES1_BUF2_SIZE_SHIFT) &
>     TDES1_BUF2_SIZE_MASK;
>
>     +    if (s->tx_frame_len + len1 > sizeof(s->tx_frame)) {
>     +        return -1;
>     +    }
>          if (len1) {
>              pci_dma_read(&s->dev, desc->buf_addr1,
>                  s->tx_frame + s->tx_frame_len, len1);
>              s->tx_frame_len += len1;
>          }
>
>     +    if (s->tx_frame_len + len2 > sizeof(s->tx_frame)) {
>     +        return -1;
>     +    }
>          if (len2) {
>              pci_dma_read(&s->dev, desc->buf_addr2,
>                  s->tx_frame + s->tx_frame_len, len2);
>              s->tx_frame_len += len2;
>          }
>          desc->status = (len1 + len2) ? 0 : 0x7fffffff;
>     +
>     +    return 0;
>      }
>
>      static void tulip_setup_filter_addr(TULIPState *s, uint8_t *buf,
>     int n)
>     @@ -651,13 +667,15 @@ static uint32_t tulip_ts(TULIPState *s)
>
>      static void tulip_xmit_list_update(TULIPState *s)
>      {
>     +#define TULIP_DESC_MAX 128
>     +    uint8_t i = 0;
>          struct tulip_descriptor desc;
>
>          if (tulip_ts(s) != CSR5_TS_SUSPENDED) {
>              return;
>          }
>
>     -    for (;;) {
>     +    for (i = 0; i < TULIP_DESC_MAX; i++) {
>              tulip_desc_read(s, s->current_tx_desc, &desc);
>              tulip_dump_tx_descriptor(s, &desc);
>
>     @@ -675,10 +693,10 @@ static void
>     tulip_xmit_list_update(TULIPState *s)
>                      s->tx_frame_len = 0;
>                  }
>
>     -            tulip_copy_tx_buffers(s, &desc);
>     -
>     -            if (desc.control & TDES1_LS) {
>     -                tulip_tx(s, &desc);
>     +            if (!tulip_copy_tx_buffers(s, &desc)) {
>     +                if (desc.control & TDES1_LS) {
>     +                    tulip_tx(s, &desc);
>     +                }
>                  }
>              }
>              tulip_desc_write(s, s->current_tx_desc, &desc);
>     -- 
>     2.25.1
>
>