Bug 2536418 (CVE-2026-90350)

Summary:	CVE-2026-90350 kernel: wifi: mt76: reject out-of-range link ids in mt76_vif_link()
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` Wi-Fi driver. This vulnerability occurs because the driver does not properly check the validity of link identifiers, allowing an attacker to provide an invalid identifier. This can lead to reading memory outside of its intended boundaries, which may result in information disclosure or cause the system to become unstable (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 17:45:26 UTC

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

wifi: mt76: reject out-of-range link ids in mt76_vif_link()

mt76_vif_link() indexes mvif->link[] without validating link_id, but
callers pass mvif->deflink_id / msta->deflink_id, which hold
IEEE80211_LINK_UNSPECIFIED (0xf) until the first link has been added.
Since IEEE80211_MLD_MAX_NUM_LINKS is 15, that reads one element past the
end of the array, aliasing mt76_vif_data.offchannel_link.

Reachable via mt7996_set_tsf()/mt7996_offset_tsf() and
mt7996_net_fill_forward_path(). Bounds check link_id and return NULL,
matching mt7996_sta_link() and mt7996_sta_link_protected().

Comment 1 gkamathe 2026-09-22 06:13:45 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90350.mbox