Bug 2521374 (CVE-2026-74648)

Summary:	CVE-2026-74648 kernel: staging: rtl8723bs: validate monitor transmit frame lengths
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's `rtl8723bs` Wi-Fi driver. This vulnerability occurs because the `rtw_cfg80211_monitor_if_xmit_entry()` function does not properly validate the length of monitor transmit frames after processing. A remote attacker could exploit this by sending a specially crafted, truncated frame, which may lead to out-of-bounds reads or insufficient data for Ethernet address writes. This could result in information disclosure or a denial of service (DoS).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-08-22 15:42:23 UTC

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

staging: rtl8723bs: validate monitor transmit frame lengths

rtw_cfg80211_monitor_if_xmit_entry() removes the radiotap header and
then reads the 802.11 frame control field without checking that a base
802.11 header remains.

The data path also pulls the calculated 802.11, QoS and SNAP header
span before confirming that the skb contains it. A truncated frame can
therefore cause out-of-bounds reads or leave insufficient data for the
Ethernet address writes.

Reject frames that do not contain the base 802.11 header and data
frames that do not contain their complete calculated header span.

Comment 1 gkamathe 2026-08-24 08:56:13 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082225-CVE-2026-74648-1dcb@gregkh/T