Bug 2541079 (CVE-2026-98017)

Summary:	CVE-2026-98017 kernel: net/sched: defer qdisc freeing after failed creation
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 network traffic control subsystem. This flaw allows a local user with network administration privileges to cause a denial of service (DoS) or potentially escalate privileges. A use-after-free condition occurs when the kernel prematurely deallocates network queueing structures after a failed configuration request while concurrent packet processing routines are still referencing them.	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 2026-09-25 10:46:22 UTC

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

net/sched: defer qdisc freeing after failed creation

An RTM_NEWQDISC request can make clsact bind a populated shared ingress
block during ->init(), publishing an embedded mini_Qdisc to lockless
readers.  If the same request has an invalid TCA_RATE, estimator setup
fails after ->init(); the unwind removes the pointer but synchronously
frees its containing qdisc while tc_run() may still hold it.

Retire failed qdiscs through the same RCU helper as normal destruction.
Inline the synchronous free into the callback now that no direct callers
remain.

Comment 1 Keith Grant 2026-09-28 20:28:33 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98017.mbox