Bug 2540223 (CVE-2026-93222)

Summary:	CVE-2026-93222 kernel: signal: avoid shared siginfo namespace rewrites
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
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:
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Doc Text:	A flaw was found in the Linux kernel's signal handling subsystem. When dispatching signals to a group of processes across different namespaces, the kernel modified shared signal metadata in place rather than copying it for each recipient. A local user could exploit this behavior to cause recipient processes in different namespaces to observe incorrect sender identifiers, such as process IDs and user IDs. This issue can lead to credential confusion and potentially bypass access controls or trust assumptions in receiving applications.	Story Points:	---
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-24 15:43:21 UTC

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

signal: avoid shared siginfo namespace rewrites

send_signal_locked() rewrites sender ids for the target namespace.  Group
sends reuse the same siginfo, so one recipient can affect the next.

Copy the siginfo before changing it.

Comment 1 Mauro Matteo Cascella 2026-09-25 10:49:08 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93222.mbox