CVE-2026-64498: iio: buffer: hw-consumer: free scan_mask on buffer release

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

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

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

iio: buffer: hw-consumer: free scan_mask on buffer release

The scan_mask lifetime changed in commit 9a2e1233d38c ("iio: buffer:
hw-consumer: remove redundant scan_mask flexible array").

Before that change, the scan mask storage was embedded in struct
hw_consumer_buffer, so iio_hw_buf_release() could free the whole
allocation with a single kfree(hw_buf).

That commit moved the scan mask to a separate bitmap_zalloc() allocation
stored in buffer.scan_mask, but left iio_hw_buf_release() unchanged.

Free the scan mask in iio_hw_buf_release() before freeing the buffer
wrapper.

The Linux kernel CVE team has assigned CVE-2026-64498 to this issue.


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

	Issue introduced in 7.1 with commit 9a2e1233d38c460ad07f36901931f3674a32d1ed and fixed in 7.1.4 with commit fb8e18f8ca724bd4de4643cad5b7c7230b9a5a71
	Issue introduced in 7.1 with commit 9a2e1233d38c460ad07f36901931f3674a32d1ed and fixed in 7.2-rc1 with commit 6325d6e2204327965b849c0a16efb6ac9202e5a8

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-2026-64498
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/iio/buffer/industrialio-hw-consumer.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/fb8e18f8ca724bd4de4643cad5b7c7230b9a5a71
	https://git.kernel.org/stable/c/6325d6e2204327965b849c0a16efb6ac9202e5a8