Bug 2468261 (CVE-2026-43400)

Summary:	CVE-2026-43400 kernel: drm/amdgpu: add upper bound check on user inputs in signal ioctl
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
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Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's `drm/amdgpu` module. A local user could exploit this vulnerability by providing excessively large input values to the `amdgpu_userq_signal_ioctl` function. This lack of proper input validation can lead to an Out-Of-Memory (OOM) condition, causing a Denial of Service (DoS) on the affected system.	Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-08 15:07:34 UTC

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

drm/amdgpu: add upper bound check on user inputs in signal ioctl

Huge input values in amdgpu_userq_signal_ioctl can lead to a OOM and
could be exploited.

So check these input value against AMDGPU_USERQ_MAX_HANDLES
which is big enough value for genuine use cases and could
potentially avoid OOM.

(cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)

Comment 1 Keith Grant 2026-05-08 22:04:27 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050839-CVE-2026-43400-3a71@gregkh/T