Bug 2536575 (CVE-2026-93077)

Summary:	CVE-2026-93077 kernel: cxl/features: Clamp Get Feature output size to the remaining buffer
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:	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 cxl/features component. The `cxl_get_feature()` function, when reading feature data, uses a fixed output buffer size in a loop. This can lead to a buffer overflow if a connected device returns more data than the remaining buffer capacity, potentially allowing for memory corruption.	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 18:28:46 UTC

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

cxl/features: Clamp Get Feature output size to the remaining buffer

cxl_get_feature() reads a feature in a loop but passes a fixed size_out
as the output capacity every iteration. On the last partial iteration
the buffer has less room left, so a device that returns more than asked
can overflow feat_out.

Use the per-iter size data_to_rd_size, which already tracks the
remaining room, as the output capacity.

Comment 1 gkamathe 2026-09-19 23:07:59 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93077.mbox