CVE Catalog

CVE-2026-64600

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.51%

41th percentile - higher than 41% of all known CVEs

Summary

In the Linux kernel, a vulnerability in XFS filesystem: functions xfs_reflink_fill_cow_hole and xfs_reflink_fill_delalloc cycle the ILOCK to grab a transaction, causing data fork mappings to become stale. Failure to refresh the data fork mapping before re-querying the COW mapping can lead to incorrect *shared values, potentially causing writes to wrong physical blocks.

Risk Assessment

The risk is potential data corruption or filesystem integrity compromise due to writes to incorrect physical blocks.

Recommendation

Update the Linux kernel to a version containing the fix for this vulnerability and monitor XFS filesystems for potential corruption.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS