CVE-2026-68331: dpaa2-eth: put MAC endpoint device on disconnect

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

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

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

dpaa2-eth: put MAC endpoint device on disconnect

fsl_mc_get_endpoint() returns the MAC endpoint device with a reference
taken through device_find_child(). The Ethernet connect path stores that
device in mac->mc_dev and keeps it for the lifetime of the connected MAC
object.

However, the disconnect path only disconnects and closes the MAC before
freeing the dpaa2_mac object. It does not drop the endpoint device
reference stored in mac->mc_dev, so every successful connect leaks that
device reference when the MAC is later disconnected.

Drop the endpoint device reference after closing the MAC and before
freeing the dpaa2_mac object.

The Linux kernel CVE team has assigned CVE-2026-68331 to this issue.


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

	Issue introduced in 5.5 with commit 71947923089353f23f4f210864903c4dcf2c1696 and fixed in 6.6.148 with commit 915012e923316b8b5d5bf8fc771617b47bd7572d
	Issue introduced in 5.5 with commit 71947923089353f23f4f210864903c4dcf2c1696 and fixed in 6.12.101 with commit e23e4a3b9dfd893469c731318d409cdf04fb1ddf
	Issue introduced in 5.5 with commit 71947923089353f23f4f210864903c4dcf2c1696 and fixed in 6.18.42 with commit f112df0744e2d77baa68eeebb860021bbaaa022a
	Issue introduced in 5.5 with commit 71947923089353f23f4f210864903c4dcf2c1696 and fixed in 7.1.6 with commit a3cecf169cc652b558d08661bb6ce55e4c933ec0
	Issue introduced in 5.5 with commit 71947923089353f23f4f210864903c4dcf2c1696 and fixed in 7.2-rc5 with commit b4b201cc93ff70150853aba03e14d314d1980ca0

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-2026-68331
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/freescale/dpaa2/dpaa2-eth.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/915012e923316b8b5d5bf8fc771617b47bd7572d
	https://git.kernel.org/stable/c/e23e4a3b9dfd893469c731318d409cdf04fb1ddf
	https://git.kernel.org/stable/c/f112df0744e2d77baa68eeebb860021bbaaa022a
	https://git.kernel.org/stable/c/a3cecf169cc652b558d08661bb6ce55e4c933ec0
	https://git.kernel.org/stable/c/b4b201cc93ff70150853aba03e14d314d1980ca0