Bug 2536258 (CVE-2026-90372)

Summary:	CVE-2026-90372 kernel: wifi: mt76: mt7915: avoid nss underflow in mt7915_mcu_get_sta_nss
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:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 `mt76` WiFi driver, affecting `mt7915` devices. A remote attacker, by sending a specially crafted VHT/HE MCS map with no supported spatial streams, can trigger an integer underflow in the `mt7915_mcu_get_sta_nss` function. This results in an incorrect value being written to the firmware's beamforming fields, which could lead to a denial of service for the wireless interface.	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 2026-09-17 17:10:32 UTC

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

wifi: mt76: mt7915: avoid nss underflow in mt7915_mcu_get_sta_nss

If a peer's VHT/HE MCS map has no supported spatial stream (all fields
0x3), the loop exits with nss == 0 and the function returned (u8)-1 (255),
which was then written into the firmware sta_rec_bf beamforming fields.
Clamp the result to 0.

Comment 1 gkamathe 2026-09-22 09:18:03 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90372.mbox