[PATCH for-3.18 2/5] bgmac: add check for oversized packets

Amit Pundir
2017-07-04T11:44:41Z

From: Felix Fietkau <nbd@openwrt.org>

commit 6a6c708469c9e10fd87adcc3abff164270538d62 upstream.

In very rare cases, the MAC can catch an internal buffer that is bigger
than it's supposed to be. Instead of crashing the kernel, simply pass
the buffer back to the hardware

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
---
drivers/net/ethernet/broadcom/bgmac.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c
index 7f34d91acdb9..54a7da860a2d 100644
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -373,6 +373,13 @@ static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring,
break;
}

+ if (len > BGMAC_RX_ALLOC_SIZE) {
+ bgmac_err(bgmac, "Found oversized packet at slot %d, DMA issue!\n",
+ ring->start);
+ put_page(virt_to_head_page(buf));
+ break;
+ }
+
/* Omit CRC. */
len -= ETH_FCS_LEN;

--
2.7.4