Bug 2536287 (CVE-2026-90356)

Summary:	CVE-2026-90356 kernel: wifi: mt76: mt7996: free vif links after clearing wcid entries on full reset
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
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, specifically in the mt7996 component. This vulnerability arises from an incorrect order of operations during a full reset, where Virtual Interface (VIF) links are freed before their corresponding Wireless Client ID (WCID) entries are cleared. This can lead to a use-after-free condition, allowing a local attacker to potentially cause system instability or 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 17:16:19 UTC

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

wifi: mt76: mt7996: free vif links after clearing wcid entries on full reset

mt7996_mac_reset_vif_iter() queues non-default vif links for kfree_rcu
while dev->wcid[] still holds pointers to the wcid embedded in each
freed link; mt76_reset_device() then dereferences those entries and
runs mt76_wcid_cleanup() on them. If a grace period elapses in between,
the cleanup operates on freed memory.

Run mt76_reset_device() first, so the wcid entries are cleaned up and
cleared while the links are still valid.

Comment 1 gkamathe 2026-09-22 07:06:12 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90356.mbox