Bug 2344685 (CVE-2025-21686)

Summary:	CVE-2025-21686 kernel: io_uring/rsrc: require cloned buffers to share accounting contexts
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	[REJECTED CVE] In the Linux kernel, the following vulnerability has been resolved: io_uring/rsrc: require cloned buffers to share accounting contexts	Story Points:	---
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Last Closed:		Type:	---
Regression:	---	Mount Type:	---
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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 2025-02-10 17:01:18 UTC

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

io_uring/rsrc: require cloned buffers to share accounting contexts

When IORING_REGISTER_CLONE_BUFFERS is used to clone buffers from uring
instance A to uring instance B, where A and B use different MMs for
accounting, the accounting can go wrong:
If uring instance A is closed before uring instance B, the pinned memory
counters for uring instance B will be decremented, even though the pinned
memory was originally accounted through uring instance A; so the MM of
uring instance B can end up with negative locked memory.

Comment 1 Robb Gatica 2025-02-10 18:59:53 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025021054-CVE-2025-21686-d416@gregkh/T

Comment 4 TEJ RATHI 2025-05-29 07:10:57 UTC

This CVE has been rejected by the Linux kernel community. Refer to the announcement: https://lore.kernel.org/linux-cve-announce/2025052034-REJECTED-3a7c@gregkh/

Comment added by: Automated Script