Bug 2555113 (CVE-2026-98709)

Summary:	CVE-2026-98709 kernel: kernel: mac80211: Denial of Service via use-after-free during channel switching
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 mac80211 wireless networking subsystem. During channel context switching operations across multiple virtual interfaces, improper tracking of link reservations can cause an active channel context to be released prematurely while still in use by the driver. A local attacker could exploit this flaw to trigger a use-after-free condition, resulting in a Denial of Service (DoS) through a system crash or potential memory corruption.	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 2026-10-18 15:55:11 UTC

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

wifi: mac80211: count only matching reservations in reserved switch

ieee80211_vif_use_reserved_switch() validates a replacement by counting
assigned links on ctx->replace_ctx and treating reservations too
broadly. A link can still be assigned to the old channel context while
holding a reservation that belongs to a different replacement
operation.

That can make the current replacement appear complete too early. If
another link finalizes first, the function can free the
WILL_BE_REPLACED chanctx while the unmatched link and driver still use
it, leading to a use-after-free in later beacon generation.

Require an in-place reservation to point at the current replacement
context, and require the reserved and assigned contexts to be the
matching replacement pair, before counting or moving the link.