CVE-2026-64056: net: ethernet: cortina: Make RX SKB per-port

From: Greg Kroah-Hartman <[email protected]>

Description
===========

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

net: ethernet: cortina: Make RX SKB per-port

The SKB used to assemble packets from fragments in gmac_rx()
is static local, but the Gemini has two ethernet ports, meaning
there can be races between the ports on a bad day if a device
is using both.

Make the RX SKB a per-port variable and carry it over between
invocations in the port struct instead.

Zero the pointer once we call napi_gro_frags(), on error (after
calling napi_free_frags()) or if the port is stopped.

Zero it in some place where not strictly necessary just to
emphasize what is going on.

This was found by Sashiko during normal patch review.

The Linux kernel CVE team has assigned CVE-2026-64056 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 5.10.258 with commit 27856d533eca3804008695f61c1e4d5ff984196b
	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 5.15.209 with commit b6b22824b30e48ce1df3a2e80990f4b8505deb50
	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 6.1.175 with commit 6bba24e9ebe6f1c0b356cd471e36bdc7fa434897
	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 6.6.142 with commit 3b249988d774dacf13b203817e971934a42243c4
	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 6.12.92 with commit 72158ea185b27afae163949b0e86164cb6b64e55
	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 6.18.34 with commit cfd62907f3cdbc3b6da8f49ba907c0390018fe5e
	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 7.0.11 with commit 67a35e7da7ef9d2f000aa758552a128324c604a0
	Issue introduced in 4.16 with commit 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 and fixed in 7.1 with commit 06937db21ee311ed07eba47954447245041a982d

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64056
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/cortina/gemini.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/27856d533eca3804008695f61c1e4d5ff984196b
	https://git.kernel.org/stable/c/b6b22824b30e48ce1df3a2e80990f4b8505deb50
	https://git.kernel.org/stable/c/6bba24e9ebe6f1c0b356cd471e36bdc7fa434897
	https://git.kernel.org/stable/c/3b249988d774dacf13b203817e971934a42243c4
	https://git.kernel.org/stable/c/72158ea185b27afae163949b0e86164cb6b64e55
	https://git.kernel.org/stable/c/cfd62907f3cdbc3b6da8f49ba907c0390018fe5e
	https://git.kernel.org/stable/c/67a35e7da7ef9d2f000aa758552a128324c604a0
	https://git.kernel.org/stable/c/06937db21ee311ed07eba47954447245041a982d