CVE-2026-80935: wifi: mt76: mt7996: bound the device EEPROM address before the EFUSE copy

CVE-2026-80935: wifi: mt76: mt7996: bound the device EEPROM address before the EFUSE copy

[Greg Kroah-Hartman]

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

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

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

wifi: mt76: mt7996: bound the device EEPROM address before the EFUSE copy

mt7996_mcu_get_eeprom() derives the destination of the EFUSE/EXT block
copy from the address reported by the MCU response (event->addr, a
device-controlled __le32) and clamps only the copy length, never the
destination offset into dev->mt76.eeprom.data. A malicious or
malfunctioning device can report an arbitrary address and drive an
out-of-bounds write of up to MT7996_EXT_EEPROM_BLOCK_SIZE bytes past
eeprom.data.

Reject a response whose address would place the copy outside eeprom.data
before deriving the destination pointer. Devices that echo the requested
in-bounds offset are unaffected.

The Linux kernel CVE team has assigned CVE-2026-80935 to this issue.


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

	Issue introduced in 6.2 with commit 98686cd21624c75a043e96812beadddf4f6f48e5 and fixed in 7.2.4 with commit 6be59da2063d5b3522bfde8aae0487ec095eb384
	Issue introduced in 6.2 with commit 98686cd21624c75a043e96812beadddf4f6f48e5 and fixed in 7.3-rc1 with commit 13b3c29a782033ce4a230be9e5618032813dbcd4

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-2026-80935
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/wireless/mediatek/mt76/mt7996/mcu.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/6be59da2063d5b3522bfde8aae0487ec095eb384
	https://git.kernel.org/stable/c/13b3c29a782033ce4a230be9e5618032813dbcd4