From: Doug Berger opendmb@gmail.com
[ Upstream commit 20d1f2d1b024f6be199a3bedf1578a1d21592bc5 ]
When commit 474ea9cafc45 ("net: bcmgenet: correctly pad short packets") added the call to skb_padto() it should have been located before the nr_frags parameter was read since that value could be changed when padding packets with lengths between 55 and 59 bytes (inclusive).
The use of a stale nr_frags value can cause corruption of the pad data when tx-scatter-gather is enabled. This corruption of the pad can cause invalid checksum computation when hardware offload of tx-checksum is also enabled.
Since the original reason for the padding was corrected by commit 7dd399130efb ("net: bcmgenet: fix skb_len in bcmgenet_xmit_single()") we can remove the software padding all together and make use of hardware padding of short frames as long as the hardware also always appends the FCS value to the frame.
Fixes: 474ea9cafc45 ("net: bcmgenet: correctly pad short packets") Signed-off-by: Doug Berger opendmb@gmail.com Acked-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/broadcom/genet/bcmgenet.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index 38bdfd4b46f0f..dde1c23c8e399 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -1520,11 +1520,6 @@ static netdev_tx_t bcmgenet_xmit(struct sk_buff *skb, struct net_device *dev) goto out; }
- if (skb_padto(skb, ETH_ZLEN)) { - ret = NETDEV_TX_OK; - goto out; - } - /* Retain how many bytes will be sent on the wire, without TSB inserted * by transmit checksum offload */ @@ -1571,6 +1566,9 @@ static netdev_tx_t bcmgenet_xmit(struct sk_buff *skb, struct net_device *dev) len_stat = (size << DMA_BUFLENGTH_SHIFT) | (priv->hw_params->qtag_mask << DMA_TX_QTAG_SHIFT);
+ /* Note: if we ever change from DMA_TX_APPEND_CRC below we + * will need to restore software padding of "runt" packets + */ if (!i) { len_stat |= DMA_TX_APPEND_CRC | DMA_SOP; if (skb->ip_summed == CHECKSUM_PARTIAL)