CVE-2026-64170: spi: qup: fix error pointer deref after DMA setup failure

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

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

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

spi: qup: fix error pointer deref after DMA setup failure

The driver falls back to PIO mode if DMA setup fails during probe.

Make sure to the clear the DMA channel pointers on setup failure to
avoid dereferencing an error pointer (or attempting to release a channel
a second time) on later probe errors or driver unbind.

This issue was flagged by Sashiko when reviewing a devres allocation
conversion patch.

The Linux kernel CVE team has assigned CVE-2026-64170 to this issue.


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

	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 5.10.259 with commit 0bb3bd442f0bdad3932739a61dd6c580c9c1955e
	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 5.15.210 with commit d577c55d189e7ae150973058d13e299b6855633f
	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 6.1.176 with commit 9e673affb92c29d9ba879bf4ea81c5e840166b56
	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 6.6.142 with commit 45760b72e84c1a1498f1a8a9047184c85299da20
	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 6.12.92 with commit 8f9b61d255b1e989b8913b06c8ebe0aba5e1b238
	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 6.18.34 with commit 4bb4764f2c51f03f657a28029eb0595d8223aab5
	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 7.0.11 with commit 4f4051e9d644c371c50de4a042b85bba6727d5c3
	Issue introduced in 4.1 with commit 612762e82ae6058d69b4ce734598491bf030afe7 and fixed in 7.1 with commit a7e8f3efd50a165ba0189f6dc57f7e51a7d149db

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-2026-64170
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/spi/spi-qup.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/0bb3bd442f0bdad3932739a61dd6c580c9c1955e
	https://git.kernel.org/stable/c/d577c55d189e7ae150973058d13e299b6855633f
	https://git.kernel.org/stable/c/9e673affb92c29d9ba879bf4ea81c5e840166b56
	https://git.kernel.org/stable/c/45760b72e84c1a1498f1a8a9047184c85299da20
	https://git.kernel.org/stable/c/8f9b61d255b1e989b8913b06c8ebe0aba5e1b238
	https://git.kernel.org/stable/c/4bb4764f2c51f03f657a28029eb0595d8223aab5
	https://git.kernel.org/stable/c/4f4051e9d644c371c50de4a042b85bba6727d5c3
	https://git.kernel.org/stable/c/a7e8f3efd50a165ba0189f6dc57f7e51a7d149db