Bug 2536465 (CVE-2026-93115)

Summary:	CVE-2026-93115 kernel: platform/mellanox: mlxbf-pmc: Check ACPI_COMPANION() against NULL
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
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 Mellanox mlxbf-pmc driver. A local attacker could exploit this by forcing the driver to bind to a device lacking an ACPI (Advanced Configuration and Power Interface) companion object. This action triggers a NULL pointer dereference, which can lead to a system crash and result in a 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 2026-09-17 18:04:34 UTC

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

platform/mellanox: mlxbf-pmc: Check ACPI_COMPANION() against NULL

Every platform driver can be forced to match a device that doesn't match
its list of device IDs because of device_match_driver_override(), so
platform drivers that rely on the existence of a device's ACPI companion
object need to verify its presence.

mlxbf_pmc_probe() passes the result of ACPI_COMPANION() to
acpi_device_hid(), which dereferences it, so force-binding the driver to
a device without an ACPI companion leads to a NULL pointer dereference.

Accordingly, add a requisite ACPI_COMPANION() check against NULL to the
mlxbf-pmc driver and return -ENODEV when the companion is missing.

Comment 1 gkamathe 2026-09-19 16:36:19 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93115.mbox