4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sean Anderson sean.anderson@linux.dev
[ Upstream commit cbd7ec083413c6a2e0c326d49e24ec7d12c7a9e0 ]
When sending packets under 60 bytes, up to three bytes of the buffer following the data may be leaked. Avoid this by extending all packets to ETH_ZLEN, ensuring nothing is leaked in the padding. This bug can be reproduced by running
$ ping -s 11 destination
Fixes: 9ad1a3749333 ("dpaa_eth: add support for DPAA Ethernet") Suggested-by: Eric Dumazet edumazet@google.com Signed-off-by: Sean Anderson sean.anderson@linux.dev Reviewed-by: Eric Dumazet edumazet@google.com Link: https://patch.msgid.link/20240910143144.1439910-1-sean.anderson@linux.dev Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c @@ -2055,12 +2055,12 @@ static netdev_tx_t dpaa_start_xmit(struct sk_buff *skb, struct net_device *net_dev) { const int queue_mapping = skb_get_queue_mapping(skb); - bool nonlinear = skb_is_nonlinear(skb); struct rtnl_link_stats64 *percpu_stats; struct dpaa_percpu_priv *percpu_priv; struct netdev_queue *txq; struct dpaa_priv *priv; struct qm_fd fd; + bool nonlinear; int offset = 0; int err = 0;
@@ -2070,6 +2070,13 @@ dpaa_start_xmit(struct sk_buff *skb, str
qm_fd_clear_fd(&fd);
+ /* Packet data is always read as 32-bit words, so zero out any part of + * the skb which might be sent if we have to pad the packet + */ + if (__skb_put_padto(skb, ETH_ZLEN, false)) + goto enomem; + + nonlinear = skb_is_nonlinear(skb); if (!nonlinear) { /* We're going to store the skb backpointer at the beginning * of the data buffer, so we need a privately owned skb