CVE-2026-64600

Summary

In the Linux kernel, the following vulnerability has been resolved:xfs: resample the data fork mapping after cycling ILOCKxfs_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.

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Attack profile

Affected products

• Linux3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 to before dc11be133efca5fe3a2fb02b016dee825cc12f183c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 to before b8c9aa832b52680ee40d6cab0efb081f9a69df053c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 to before 50f0012da1040f69a4e788cd9aed587c9a04983f3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 to before e705d81a7193dd19e69b8e2bad4696d78a4ea075
• Linux4.11

References