Bug 2559669 (CVE-2026-98963)

Summary:	CVE-2026-98963 kernel: btrfs: always return -EIOCBQUEUED after btrfs_uring_read_extent_endio
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
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 Btrfs file system within the Linux kernel. During asynchronous read operations, an early I/O error can cause both the direct and deferred error handling paths to release the same resources. This double-free condition can be exploited by a local user to corrupt memory and cause a system crash, leading to a Denial of Service (DoS).	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 2026-10-23 12:57:53 UTC

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

btrfs: always return -EIOCBQUEUED after btrfs_uring_read_extent_endio

If all bios finish before btrfs_encoded_read_regular_fill_pages()
returns, it calls btrfs_uring_read_extent_endio() and previously
returned the I/O status.  A negative errno then made
btrfs_uring_read_extent() unlock and free while
btrfs_uring_read_finished() did the same again.

Return -EIOCBQUEUED so only the deferred path cleans up.