Bug 2536581 (CVE-2026-93110)

Summary:	CVE-2026-93110 kernel: RDMA/core: Wait for RCU callbacks before unloading ib_core
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 RDMA core component. A race condition exists where `RCU` (Read-Copy-Update) callbacks, specifically `put_gid_ndev()`, can be invoked after the `ib_core` module has been unloaded. This occurs because stopping workqueues does not drain already queued callbacks, allowing `RCU` to call them on freed memory. This vulnerability could lead to memory corruption, potentially causing a system crash or other unpredictable behavior.	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 18:31:34 UTC

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

RDMA/core: Wait for RCU callbacks before unloading ib_core

put_gid_ndev() is queued with call_rcu() and implemented in ib_core.
Stopping the workqueues does not drain callbacks already queued, so RCU
could invoke it after the module code has been unloaded.

synchronize_rcu() does not wait for callbacks. Wait for them after all
producers have stopped.

Comment 1 gkamathe 2026-09-19 15:56:52 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93110.mbox