CVE-2026-74532: Bluetooth: btintel: Validate length before parsing diagnostics TLV

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

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

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

Bluetooth: btintel: Validate length before parsing diagnostics TLV

btintel_diagnostics() accesses tlv->val[0] without first validating
that the diagnostics VSE is long enough to contain that field, so
may cause reading data beyond the received frame.

Fix by validating the length before access.

The Linux kernel CVE team has assigned CVE-2026-74532 to this issue.


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

	Issue introduced in 6.4 with commit af395330abed142a2685bf3d17a938544816bf3c and fixed in 6.6.151 with commit c31be902ccbbb0b2c23159a1481dce80d1f9753d
	Issue introduced in 6.4 with commit af395330abed142a2685bf3d17a938544816bf3c and fixed in 6.12.103 with commit dd20e30bdbd707ea8ced581f3d7f9e9854634b17
	Issue introduced in 6.4 with commit af395330abed142a2685bf3d17a938544816bf3c and fixed in 6.18.44 with commit c618a9a5b08ea2e17bddf4e948be9f75d408fca4
	Issue introduced in 6.4 with commit af395330abed142a2685bf3d17a938544816bf3c and fixed in 7.1.8 with commit 6ec9c3dc52302b891513f608f5fb478349b15ab3
	Issue introduced in 6.4 with commit af395330abed142a2685bf3d17a938544816bf3c and fixed in 7.2-rc6 with commit b640ff9af3c809ff5ea2077fbba17df1594ec1e4

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-2026-74532
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/bluetooth/btintel.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/c31be902ccbbb0b2c23159a1481dce80d1f9753d
	https://git.kernel.org/stable/c/dd20e30bdbd707ea8ced581f3d7f9e9854634b17
	https://git.kernel.org/stable/c/c618a9a5b08ea2e17bddf4e948be9f75d408fca4
	https://git.kernel.org/stable/c/6ec9c3dc52302b891513f608f5fb478349b15ab3
	https://git.kernel.org/stable/c/b640ff9af3c809ff5ea2077fbba17df1594ec1e4