Bug 2516635 (CVE-2026-72017)

Summary:	CVE-2026-72017 kernel: net: macb: drop in-flight Tx SKBs on close
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 MACB network driver. This driver fails to properly release outgoing Socket Kernel Buffers (SKBs) when the driver is closed. This continuous leakage of resources can lead to resource exhaustion over time, potentially resulting in a Denial of Service (DoS) condition for the system.	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 2026-08-15 06:23:07 UTC

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

net: macb: drop in-flight Tx SKBs on close

The MACB driver has since forever leaked the outgoing SKBs that
have not yet been marked as completed. They live in queue->tx_skb
which gets freed without remorse nor checking.

macb_free_consistent() gets called in a few codepaths, but only close will
trigger the added expressions. In macb_open() and macb_alloc_consistent()
failure cases, queues' tx_skb just got allocated and are empty.

Comment 1 Keith Grant 2026-08-17 15:53:48 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081509-CVE-2026-72017-598c@gregkh/T