Bug 2464450 (CVE-2026-31781)

Summary:	CVE-2026-31781 kernel: drm/ioc32: stop speculation on the drm_compat_ioctl path
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:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in the Linux kernel's Direct Rendering Manager (DRM) subsystem, specifically in the `drm/ioc32` component. This vulnerability, related to speculative execution (a technique used by modern processors to guess future instructions), allows a local attacker to potentially disclose sensitive information. The `drm_compat_ioctl` path incorrectly handles user-controlled pointers, leading to a Spectre-like issue where data can be exposed through speculative execution side channels.	Story Points:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-01 15:07:29 UTC

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

drm/ioc32: stop speculation on the drm_compat_ioctl path

The drm compat ioctl path takes a user controlled pointer, and then
dereferences it into a table of function pointers, the signature method
of spectre problems.  Fix this up by calling array_index_nospec() on the
index to the function pointer list.

Comment 1 Keith Grant 2026-05-01 23:38:03 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050151-CVE-2026-31781-8a5d@gregkh/T