CVE-2026-72262: ASoC: SOF: ipc3-control: Fix heap overflow in bytes_ext put/get

CVE-2026-72262: ASoC: SOF: ipc3-control: Fix heap overflow in bytes_ext put/get

[Greg Kroah-Hartman]

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

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

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

ASoC: SOF: ipc3-control: Fix heap overflow in bytes_ext put/get

The ipc_control_data buffer is allocated as kzalloc(max_size), where
max_size covers the entire struct sof_ipc_ctrl_data including its
flexible array payload. However, the bounds checks in bytes_ext_put
and _bytes_ext_get compared user data lengths against max_size
directly, ignoring that cdata->data sits at an offset of
sizeof(struct sof_ipc_ctrl_data) bytes into the allocation.

This allowed writing up to sizeof(struct sof_ipc_ctrl_data) bytes past
the end of the heap buffer from unprivileged userspace via the ALSA TLV
kcontrol interface, and similarly allowed over-reading adjacent heap
data on the get path.

Fix all bounds checks to subtract sizeof(*cdata) from max_size so they
reflect the actual space available at the cdata->data offset. Also fix
the error-path restore in bytes_ext_put which wrote to cdata->data
instead of cdata, causing the same overflow.

The Linux kernel CVE team has assigned CVE-2026-72262 to this issue.


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

	Issue introduced in 5.18 with commit 67ec2a091630c28ea8d05db2bd7178a05b04b7e6 and fixed in 6.6.145 with commit 1adde1941bba7b0d7104b86ed819d48d81cb0ad9
	Issue introduced in 5.18 with commit 67ec2a091630c28ea8d05db2bd7178a05b04b7e6 and fixed in 6.12.97 with commit eaa67e139c9217099e2a7b717aeeb46c65de3494
	Issue introduced in 5.18 with commit 67ec2a091630c28ea8d05db2bd7178a05b04b7e6 and fixed in 6.18.40 with commit 121577383b5cf221e86581e0f2bcca4c66f17469
	Issue introduced in 5.18 with commit 67ec2a091630c28ea8d05db2bd7178a05b04b7e6 and fixed in 7.1.5 with commit f4933e1d11b97b6a0951648b7c3e53850e1b33a9
	Issue introduced in 5.18 with commit 67ec2a091630c28ea8d05db2bd7178a05b04b7e6 and fixed in 7.2-rc1 with commit fd46668d538993218eea19c6925c868ac0f2630c

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-2026-72262
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:
	sound/soc/sof/ipc3-control.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/1adde1941bba7b0d7104b86ed819d48d81cb0ad9
	https://git.kernel.org/stable/c/eaa67e139c9217099e2a7b717aeeb46c65de3494
	https://git.kernel.org/stable/c/121577383b5cf221e86581e0f2bcca4c66f17469
	https://git.kernel.org/stable/c/f4933e1d11b97b6a0951648b7c3e53850e1b33a9
	https://git.kernel.org/stable/c/fd46668d538993218eea19c6925c868ac0f2630c