Subject: CVE-2024-35850: Bluetooth: qca: fix NULL-deref on non-serdev setup

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

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

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

Bluetooth: qca: fix NULL-deref on non-serdev setup

Qualcomm ROME controllers can be registered from the Bluetooth line
discipline and in this case the HCI UART serdev pointer is NULL.

Add the missing sanity check to prevent a NULL-pointer dereference when
setup() is called for a non-serdev controller.

The Linux kernel CVE team has assigned CVE-2024-35850 to this issue.

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

	Issue introduced in 6.2 with commit e9b3e5b8c657 and fixed in 6.6.30 with commit 67459f1a707a
	Issue introduced in 6.2 with commit e9b3e5b8c657 and fixed in 6.8.9 with commit bec4d4c6fa5c
	Issue introduced in 6.2 with commit e9b3e5b8c657 and fixed in 6.9 with commit 7ddb9de6af0f

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-2024-35850
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/hci_qca.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/67459f1a707aae6d590454de07956c2752e21ea4
	https://git.kernel.org/stable/c/bec4d4c6fa5c6526409f582e4f31144e20c86c21
	https://git.kernel.org/stable/c/7ddb9de6af0f1c71147785b12fd7c8ec3f06cc86