CVE-2026-80992: net: ravb: avoid dereferencing an invalid PTP clock

CVE-2026-80992: net: ravb: avoid dereferencing an invalid PTP clock

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

net: ravb: avoid dereferencing an invalid PTP clock

The PTP clock is unavailable before the first open, so querying its
index can dereference a NULL pointer. Registration failures can also
leave an error pointer in priv->ptp.clock.

Cache the PHC index separately and report -1 while no clock is
registered. Normalize registration errors to NULL and preserve the
static timestamping capabilities.

The Linux kernel CVE team has assigned CVE-2026-80992 to this issue.


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

	Issue introduced in 4.2 with commit a0d2f20650e81407d8e51ad2cbdc492861c74e9c and fixed in 6.12.109 with commit fc710f89a644e030a7ca15343176ca862fd61b9d
	Issue introduced in 4.2 with commit a0d2f20650e81407d8e51ad2cbdc492861c74e9c and fixed in 6.18.50 with commit 8d4d06d6e2b501cb8e30ed3b1924c470358e8052
	Issue introduced in 4.2 with commit a0d2f20650e81407d8e51ad2cbdc492861c74e9c and fixed in 7.2.4 with commit 0aaa53936419cf0c19c670387fc6d431e042a1b6
	Issue introduced in 4.2 with commit a0d2f20650e81407d8e51ad2cbdc492861c74e9c and fixed in 7.3-rc1 with commit 1f77af0aaf277413ff32f6ff8c2c4282bd64c897

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-2026-80992
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/renesas/ravb.h
	drivers/net/ethernet/renesas/ravb_main.c
	drivers/net/ethernet/renesas/ravb_ptp.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/fc710f89a644e030a7ca15343176ca862fd61b9d
	https://git.kernel.org/stable/c/8d4d06d6e2b501cb8e30ed3b1924c470358e8052
	https://git.kernel.org/stable/c/0aaa53936419cf0c19c670387fc6d431e042a1b6
	https://git.kernel.org/stable/c/1f77af0aaf277413ff32f6ff8c2c4282bd64c897