CVE-2026-64600

CVE Details

Release Date:	2026-07-23
Impact:	Important	What is this?

Description

In the Linux kernel, the following vulnerability has been resolved: xfs: resample the data fork mapping after cycling ILOCK xfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode, a data fork mapping, and a cow fork mapping. Unfortunately, these two helpers cycle the ILOCK to grab a transaction, which means that the mappings are stale as soon as we reacquire the ILOCK. Currently we refresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but we don't refresh the data fork mapping beforehand, which means that the xfs_bmap_trim_cow in that function queries the refcount btree about the wrong physical blocks and returns an inaccurate value in *shared. If *shared is now false, the directio write proceeds with a stale data fork mapping. Fix this by querying the data fork mapping if the sequence counter changes across the ILOCK cycle.

See more information about CVE-2026-64600 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	7.8
Vector String:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Version:	3.1
Attack Vector:	Local
Attack Complexity:	Low
Privileges Required:	Low
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	High
Integrity Impact:	High
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 10 (kernel)	ELSA-2026-39494	2026-07-16
Oracle Linux version 7 (kernel-uek)	ELBA-2026-500009	2026-07-16
Oracle Linux version 7 (kernel-uek)	ELSA-2026-500121	2026-08-03
Oracle Linux version 8 (kernel-uek)	ELBA-2026-500009	2026-07-16
Oracle Linux version 8 (kernel-uek)	ELBA-2026-500010	2026-07-16
Oracle Linux version 8 (kernel-uek)	ELSA-2026-500121	2026-08-03
Oracle Linux version 9 (kernel-uek)	ELBA-2026-500010	2026-07-16