Bug 2546411 (CVE-2026-98251)

Summary:	CVE-2026-98251 kernel: openvswitch: avoid reallocating confirmed conntrack labels
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 Open vSwitch component. When handling network connection tracking (conntrack) labels, the kernel may reallocate memory for active connections while another processor accesses it simultaneously. This race condition can lead to memory corruption, allowing an attacker to cause a system crash and a Denial of Service (DoS).	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 2026-10-06 09:16:44 UTC

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

openvswitch: avoid reallocating confirmed conntrack labels

ovs_ct_get_conn_labels() adds the labels extension when a conntrack
entry does not have one.  Confirmed conntracks can be read locklessly,
so adding an extension may reallocate and free the extension block
while another CPU accesses it.

Only add the extension for unconfirmed conntracks.  A confirmed
conntrack without labels now fails the caller's label operation instead
of reallocating its extension storage.

Comment 1 gkamathe 2026-10-10 17:14:05 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98251.mbox