Bug 2516323 (CVE-2026-72345)

Summary:	CVE-2026-72345 kernel: net/mlx5: LAG, Fix off-by-one in single-FDB error rollback
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 mlx5 LAG (Link Aggregation Group) driver. An off-by-one error in the `mlx5_lag_create_single_fdb()` function's error rollback mechanism can lead to operations on uninitialized memory or a double-free condition. This could result in system instability or a 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 2026-08-15 06:06:29 UTC

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

net/mlx5: LAG, Fix off-by-one in single-FDB error rollback

On failure at index i, the reverse cleanup loop in
mlx5_lag_create_single_fdb() starts from i, so the failed index
itself is rolled back. That can operate on uninitialized state or
double-tear-down a rule the add_one path already self-rolled-back.

Start the rollback from i - 1 so only successfully-installed entries
are undone.

Comment 1 gkamathe 2026-08-19 13:55:15 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081511-CVE-2026-72345-d024@gregkh/T