CVE-2026-64443: staging: rtl8723bs: fix OOB read in update_beacon_info() IE loop

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

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

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

staging: rtl8723bs: fix OOB read in update_beacon_info() IE loop

The IE parsing loop in update_beacon_info() advances by
(pIE->length + 2) each iteration but only guards on i < len.
When a malicious AP sends a Beacon whose last IE has only one byte
remaining in the frame (the element_id byte lands at len-1), the loop
reads pIE->length from one byte past the allocated receive buffer.

Additionally, even when the header bytes are in bounds, pIE->length
itself can extend the data window beyond len, passing a truncated IE
to the handler functions.

Add two guards at the top of the loop body:
  1. Break if fewer than sizeof(*pIE) bytes remain (can't read header).
  2. Break if the IE's declared data extends past len.

Also replace i += (pIE->length + 2) with i += sizeof(*pIE) + pIE->length
for consistency with the sizeof(*pIE) guards added above.

The Linux kernel CVE team has assigned CVE-2026-64443 to this issue.


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

	Issue introduced in 4.12 with commit 554c0a3abf216c991c5ebddcdb2c08689ecd290b and fixed in 5.15.212 with commit 5e8db4cff5b45c7c4edc8ae3f302027c3bb32b25
	Issue introduced in 4.12 with commit 554c0a3abf216c991c5ebddcdb2c08689ecd290b and fixed in 6.1.178 with commit 6dd5e8c3011ebabf417257d7f07901a7c4311539
	Issue introduced in 4.12 with commit 554c0a3abf216c991c5ebddcdb2c08689ecd290b and fixed in 6.6.145 with commit 9193c34f75fd9e1ea8a590d7cced464c3380dc29
	Issue introduced in 4.12 with commit 554c0a3abf216c991c5ebddcdb2c08689ecd290b and fixed in 6.12.96 with commit bd953d52d587d42365e399b96c52dbdb13032070
	Issue introduced in 4.12 with commit 554c0a3abf216c991c5ebddcdb2c08689ecd290b and fixed in 6.18.39 with commit 69f174a0673b6b7a29b851adb60bc450cdc0ecc4
	Issue introduced in 4.12 with commit 554c0a3abf216c991c5ebddcdb2c08689ecd290b and fixed in 7.1.4 with commit b5cc2f999927f69723ca53f1f2a3aa37dbeda907
	Issue introduced in 4.12 with commit 554c0a3abf216c991c5ebddcdb2c08689ecd290b and fixed in 7.2-rc3 with commit ed51de4a86e173c3b0ef78e039c2e49e08b11f16

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-2026-64443
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/staging/rtl8723bs/core/rtw_wlan_util.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/5e8db4cff5b45c7c4edc8ae3f302027c3bb32b25
	https://git.kernel.org/stable/c/6dd5e8c3011ebabf417257d7f07901a7c4311539
	https://git.kernel.org/stable/c/9193c34f75fd9e1ea8a590d7cced464c3380dc29
	https://git.kernel.org/stable/c/bd953d52d587d42365e399b96c52dbdb13032070
	https://git.kernel.org/stable/c/69f174a0673b6b7a29b851adb60bc450cdc0ecc4
	https://git.kernel.org/stable/c/b5cc2f999927f69723ca53f1f2a3aa37dbeda907
	https://git.kernel.org/stable/c/ed51de4a86e173c3b0ef78e039c2e49e08b11f16