Bug 2516296 (CVE-2026-72370)

Summary:	CVE-2026-72370 kernel: iomap: release pages on atomic dio size mismatch
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 `iomap` subsystem. When handling atomic direct I/O (DIO) operations, if a bio (a data structure representing I/O requests) is built with a size mismatch and subsequently rejected, the kernel's error handling path fails to release the associated memory pages. This oversight can lead to a resource leak, potentially causing memory exhaustion and a Denial of Service (DoS) condition on the affected system.	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 2026-08-15 06:05:06 UTC

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

iomap: release pages on atomic dio size mismatch

If bio_iov_iter_get_pages() or the bounce helper succeeds but builds a
short bio, the REQ_ATOMIC size check rejects it before submission.  The
old error path only dropped the bio reference, leaving any pages already
attached to the bio unreleased.

Release or unbounce the pages before falling through to out_put_bio on
this error path.

This bug was reported by sashiko:
https://sashiko.dev/#/patchset/20260608073134.95964-1-changfengnan%40bytedance.com

Comment 1 gkamathe 2026-08-18 05:42:20 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081515-CVE-2026-72370-d161@gregkh/T