From patchwork Wed Jan 16 23:36:37 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: net: calxedaxgmac: throw away overrun frames From: Rob Herring X-Patchwork-Id: 213099 Message-Id: <1358379397-7152-1-git-send-email-robherring2@gmail.com> To: netdev@vger.kernel.org Cc: Rob Herring , linux-kernel@vger.kernel.org Date: Wed, 16 Jan 2013 17:36:37 -0600 From: Rob Herring The xgmac driver assumes 1 frame per descriptor. If a frame larger than the descriptor's buffer size is received, the frame will spill over into the next descriptor. So check for received frames that span more than one descriptor and discard them. This prevents a crash if we receive erroneous large packets. Signed-off-by: Rob Herring Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- drivers/net/ethernet/calxeda/xgmac.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c index b407043..f7f0290 100644 --- a/drivers/net/ethernet/calxeda/xgmac.c +++ b/drivers/net/ethernet/calxeda/xgmac.c @@ -548,6 +548,10 @@ static int desc_get_rx_status(struct xgmac_priv *priv, struct xgmac_dma_desc *p) return -1; } + /* All frames should fit into a single buffer */ + if (!(status & RXDESC_FIRST_SEG) || !(status & RXDESC_LAST_SEG)) + return -1; + /* Check if packet has checksum already */ if ((status & RXDESC_FRAME_TYPE) && (status & RXDESC_EXT_STATUS) && !(ext_status & RXDESC_IP_PAYLOAD_MASK))