CVE-2026-46092: wifi: rtw88: check for PCI upstream bridge existence

CVE-2026-46092: wifi: rtw88: check for PCI upstream bridge existence

[Greg Kroah-Hartman]

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

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

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

wifi: rtw88: check for PCI upstream bridge existence

pci_upstream_bridge() returns NULL if the device is on a root bus.  If
8821CE is installed in the system with such a PCI topology, the probing
routine will crash.  This has probably been unnoticed as 8821CE is mostly
supplied in laptops where there is a PCI-to-PCI bridge located upstream
from the device.  However the card might be installed on a system with
different configuration.

Check if the bridge does exist for the specific workaround to be applied.

Found by Linux Verification Center (linuxtesting.org) with Svace static
analysis tool.

The Linux kernel CVE team has assigned CVE-2026-46092 to this issue.


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

	Issue introduced in 5.17 with commit 24f5e38a13b5ae2b6105cda8bb47c19108e62a9a and fixed in 7.1-rc1 with commit eb101d2abdcccb514ca4fccd3b278dd8267374f6
	Issue introduced in 5.15.17 with commit 617339466fda09916c4b4151fa5e6a9c1fdae353
	Issue introduced in 5.16.3 with commit f21e8cb927fa9da49490b74ddda3856a828b82d6

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-2026-46092
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/net/wireless/realtek/rtw88/pci.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/eb101d2abdcccb514ca4fccd3b278dd8267374f6