Affected: Linux, Siemens RUGGEDCOM RST2428P, Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family, Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family, Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

In the Linux kernel, the following vulnerability has been resolved:

net: ethernet: lantiq_etop: fix memory disclosure

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.