This is a note to let you know that I've just added the patch titled net: ethernet: lantiq_etop: fix memory disclosure to the 6.1-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-ethernet-lantiq_etop-fix-memory-disclosure.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3a5e18c37ffa1eb6da52382ebc2d1de8d93d1e3a Author: Aleksander Jan Bajkowski <olek2@xxxxx> Date: Mon Sep 23 23:49:49 2024 +0200 net: ethernet: lantiq_etop: fix memory disclosure [ Upstream commit 45c0de18ff2dc9af01236380404bbd6a46502c69 ] When applying padding, the buffer is not zeroed, which results in memory disclosure. The mentioned data is observed on the wire. This patch uses skb_put_padto() to pad Ethernet frames properly. The mentioned function zeroes the expanded buffer. In case the packet cannot be padded it is silently dropped. Statistics are also not incremented. This driver does not support statistics in the old 32-bit format or the new 64-bit format. These will be added in the future. In its current form, the patch should be easily backported to stable versions. Ethernet MACs on Amazon-SE and Danube cannot do padding of the packets in hardware, so software padding must be applied. Fixes: 504d4721ee8e ("MIPS: Lantiq: Add ethernet driver") Signed-off-by: Aleksander Jan Bajkowski <olek2@xxxxx> Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx> Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> Link: https://patch.msgid.link/20240923214949.231511-2-olek2@xxxxx Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/lantiq_etop.c b/drivers/net/ethernet/lantiq_etop.c index 61baf1da76eea..c33c31019562f 100644 --- a/drivers/net/ethernet/lantiq_etop.c +++ b/drivers/net/ethernet/lantiq_etop.c @@ -482,7 +482,9 @@ ltq_etop_tx(struct sk_buff *skb, struct net_device *dev) unsigned long flags; u32 byte_offset; - len = skb->len < ETH_ZLEN ? ETH_ZLEN : skb->len; + if (skb_put_padto(skb, ETH_ZLEN)) + return NETDEV_TX_OK; + len = skb->len; if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) { netdev_err(dev, "tx ring full\n");