Bug 2540398 (CVE-2026-93821)

Summary:	CVE-2026-93821 kernel: PCI: altera: Protect root bus removal with rescan lock
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 Altera PCI Express (PCIe) controller driver. A local user could exploit a race condition during root bus removal by triggering concurrent device rescan or hotplug operations through the sysfs interface. This lack of proper synchronization can lead to a use-after-free memory flaw, resulting in a system crash and Denial of Service (DoS).	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 2026-09-24 16:41:01 UTC

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

PCI: altera: Protect root bus removal with rescan lock

Hold the pci_rescan_remove_lock lock while stopping and removing a root bus
to avoid racing with concurrent rescan or hotplug operations triggered via
sysfs.  Such races may lead to use-after-free issues or system crashes.

[bhelgaas: commit log]

Comment 1 Mauro Matteo Cascella 2026-09-28 15:01:29 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93821.mbox