Bug 2536669 (CVE-2026-93109)

Summary:	CVE-2026-93109 kernel: RDMA/mlx5: Drain RCU callbacks during module teardown
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
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 RDMA/mlx5 component. A race condition during module teardown can occur when the mlx5_ib module unloads before all Read-Copy-Update (RCU) callbacks, such as devx_free_subscription(), have completed. This premature unloading while callbacks are still pending can lead to system instability or a crash, resulting in 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 2026-09-17 19:04:06 UTC

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

RDMA/mlx5: Drain RCU callbacks during module teardown

devx_free_subscription() can remain queued after the last DevX event file
drops its module reference or an auxiliary driver detaches its devices.
mlx5_ib can then unload before the callback runs.

Registration error unwind has the same risk because driver registration
can attach existing devices before failing. Wait after all drivers have
stopped.

Comment 1 gkamathe 2026-09-19 15:50:30 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93109.mbox