This is a note to let you know that I've just added the patch titled net: dpaa: Pad packets to ETH_ZLEN to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dpaa-pad-packets-to-eth_zlen.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 05beecce07488966cfd794c219a3b83399f1ee54 Author: Sean Anderson <sean.anderson@xxxxxxxxx> Date: Tue Sep 10 10:31:44 2024 -0400 net: dpaa: Pad packets to ETH_ZLEN [ 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@xxxxxxxxxx> Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxxx> Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx> Link: https://patch.msgid.link/20240910143144.1439910-1-sean.anderson@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c index c6a3eefd83bf..e7bf70ac9a4c 100644 --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c @@ -2285,12 +2285,12 @@ 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; @@ -2300,6 +2300,13 @@ dpaa_start_xmit(struct sk_buff *skb, struct net_device *net_dev) 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