CVE-2026-68467: mtd: mchp23k256: use SPI match data for chip caps

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

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

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

mtd: mchp23k256: use SPI match data for chip caps

The driver stores chip capacity information in both the OF match table
and the SPI id table. Probe currently uses of_device_get_match_data(),
so a non-OF SPI modalias match falls back to mchp23k256_caps even when
the SPI id table selected a different part.

Use spi_get_device_match_data() so SPI id-table driver_data is consumed
when OF match data is absent. This keeps the existing default fallback
while avoiding the wrong MTD geometry for id-table-only matches.

The Linux kernel CVE team has assigned CVE-2026-68467 to this issue.


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

	Issue introduced in 4.13 with commit 4379075a870b8de43a9ecd5b46884953234fc669 and fixed in 5.15.212 with commit 2e179b028da9fd628a09286a2c9df4fa076b2cc9
	Issue introduced in 4.13 with commit 4379075a870b8de43a9ecd5b46884953234fc669 and fixed in 6.1.178 with commit a0c38083623c8b210a5b87fd34bebd05aa935ae8
	Issue introduced in 4.13 with commit 4379075a870b8de43a9ecd5b46884953234fc669 and fixed in 6.6.145 with commit 7c0a3a73dccc9a3fc701f6be762449f18d0ca0fc
	Issue introduced in 4.13 with commit 4379075a870b8de43a9ecd5b46884953234fc669 and fixed in 6.12.97 with commit dbe2254d1da99c986f9a3392471fc5eaa3229647
	Issue introduced in 4.13 with commit 4379075a870b8de43a9ecd5b46884953234fc669 and fixed in 6.18.40 with commit 04ebd3766861f219325852c9598e0f0281cb3636
	Issue introduced in 4.13 with commit 4379075a870b8de43a9ecd5b46884953234fc669 and fixed in 7.1.5 with commit 09e044192a42f716215fbd1a100ee87fa57426aa
	Issue introduced in 4.13 with commit 4379075a870b8de43a9ecd5b46884953234fc669 and fixed in 7.2-rc4 with commit d322e40f4edf92bf0ca329e5aa4ae1c0316feb38

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-2026-68467
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/mtd/devices/mchp23k256.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/2e179b028da9fd628a09286a2c9df4fa076b2cc9
	https://git.kernel.org/stable/c/a0c38083623c8b210a5b87fd34bebd05aa935ae8
	https://git.kernel.org/stable/c/7c0a3a73dccc9a3fc701f6be762449f18d0ca0fc
	https://git.kernel.org/stable/c/dbe2254d1da99c986f9a3392471fc5eaa3229647
	https://git.kernel.org/stable/c/04ebd3766861f219325852c9598e0f0281cb3636
	https://git.kernel.org/stable/c/09e044192a42f716215fbd1a100ee87fa57426aa
	https://git.kernel.org/stable/c/d322e40f4edf92bf0ca329e5aa4ae1c0316feb38