4.19-stable review patch. If anyone has any objections, please let me know.
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From: Aleksander Jan Bajkowski olek2@wp.pl
[ 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@wp.pl Reviewed-by: Jacob Keller jacob.e.keller@intel.com Reviewed-by: Florian Fainelli florian.fainelli@broadcom.com Link: https://patch.msgid.link/20240923214949.231511-2-olek2@wp.pl Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/lantiq_etop.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/lantiq_etop.c b/drivers/net/ethernet/lantiq_etop.c index b41822d08649d..d492b8899d32a 100644 --- a/drivers/net/ethernet/lantiq_etop.c +++ b/drivers/net/ethernet/lantiq_etop.c @@ -478,7 +478,9 @@ 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");