Bug 2536742 (CVE-2026-90376)

Summary:	CVE-2026-90376 kernel: wifi: mt76: mt7996: fix MLD ID in MAC TXD and HIF TXP
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 MediaTek mt76 Wi-Fi driver within the Linux kernel. An incorrect Multi-Link Device (MLD) ID in the MAC Transmit Descriptor (TXD) and Host Interface Transmit Packet (HIF TXP) can cause the firmware to enter a busy loop. This issue occurs when a third MLD link is in power saving mode, leading to a Microcontroller Unit (MCU) command timeout and a denial of service.	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 19:23:57 UTC

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

wifi: mt76: mt7996: fix MLD ID in MAC TXD and HIF TXP

Problem:
MCU command timeout while the firmware state is normal, and the
firmware keeps showing the error log "ERROR!! NO PAUSE...".

Root cause:
If the MLD_ID field in the TXD is neither the primary link id nor the
secondary link id, it may lead to a firmware busy loop when the third
link is in power saving mode.

Remap frames directed to a third link to the primary link wcid. Since
TX status events and txfree completions carry the wcid the firmware
saw, use the remapped wcid for packet id tracking and non-AQL packet
accounting as well, while the frame keeps its original link context
for addressing, band and OMAC selection.

Comment 1 gkamathe 2026-09-22 10:02:19 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90376.mbox