Bug 2492096 (CVE-2026-52928)

Summary:	CVE-2026-52928 kernel: af_unix: Reject SIOCATMARK on non-stream sockets
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:	rhel-process-autobot, 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 `af_unix` component. This vulnerability involves the incorrect handling of the `SIOCATMARK` operation when used with non-stream sockets, such as `SOCK_DGRAM` and `SOCK_SEQPACKET`. These socket types did not properly reject `SIOCATMARK`, an operation intended only for `SOCK_STREAM` sockets. This could lead to unexpected system behavior when an application attempts to perform this unsupported operation.	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 2026-06-24 08:01:48 UTC

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

af_unix: Reject SIOCATMARK on non-stream sockets

SIOCATMARK reports whether the receive queue is at the urgent mark for
MSG_OOB.

In AF_UNIX, MSG_OOB is supported only for SOCK_STREAM sockets.
SOCK_DGRAM and SOCK_SEQPACKET reject MSG_OOB in sendmsg() and recvmsg(),
so they should not support SIOCATMARK either.

Return -EOPNOTSUPP for non-stream sockets before checking the receive
queue.

Comment 1 Mauro Matteo Cascella 2026-06-24 16:43:47 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062432-CVE-2026-52928-de38@gregkh/T