CVE-2026-74693: net: prestera: validate firmware header length

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

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

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

net: prestera: validate firmware header length

prestera_fw_hdr_parse() reads the firmware header before checking
that the firmware image contains that header.

Reject images shorter than struct prestera_fw_header before decoding the
magic and version fields.

The Linux kernel CVE team has assigned CVE-2026-74693 to this issue.


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

	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 5.10.265 with commit 38a3afbf9fd8a2e8c47fa3ca47b425a8a9623240
	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 5.15.216 with commit 0fbcceb9d19f2d1dcdf099aee590f2517cb718bb
	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 6.1.183 with commit e0f382e8084117f0b11ffb070fe1079e38c0d7f9
	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 6.6.152 with commit 6fad06bb793d7089ae05b9fcf46e11be2dfe4850
	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 6.12.104 with commit 470ac9cce7308e60cf2dceb448749cdd006e73de
	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 6.18.45 with commit 363e048a9d0a6c245cbc348c8a220170afed046a
	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 7.1.9 with commit 7fa8a12296d8d5aa4b1c3904f0b354d81124cf29
	Issue introduced in 5.10 with commit 4c2703dfd7fabb0824b3bc345f9fa47e33248c14 and fixed in 7.2 with commit 8ae344eb540af3f457179b52bc6061416752485c

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-2026-74693
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/marvell/prestera/prestera_pci.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/38a3afbf9fd8a2e8c47fa3ca47b425a8a9623240
	https://git.kernel.org/stable/c/0fbcceb9d19f2d1dcdf099aee590f2517cb718bb
	https://git.kernel.org/stable/c/e0f382e8084117f0b11ffb070fe1079e38c0d7f9
	https://git.kernel.org/stable/c/6fad06bb793d7089ae05b9fcf46e11be2dfe4850
	https://git.kernel.org/stable/c/470ac9cce7308e60cf2dceb448749cdd006e73de
	https://git.kernel.org/stable/c/363e048a9d0a6c245cbc348c8a220170afed046a
	https://git.kernel.org/stable/c/7fa8a12296d8d5aa4b1c3904f0b354d81124cf29
	https://git.kernel.org/stable/c/8ae344eb540af3f457179b52bc6061416752485c