{"id":"CVE-2026-64600","summary":"xfs: resample the data fork mapping after cycling ILOCK","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: resample the data fork mapping after cycling ILOCK\n\nxfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode,\na data fork mapping, and a cow fork mapping.  Unfortunately, these two\nhelpers cycle the ILOCK to grab a transaction, which means that the\nmappings are stale as soon as we reacquire the ILOCK.  Currently we\nrefresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but\nwe don't refresh the data fork mapping beforehand, which means that the\nxfs_bmap_trim_cow in that function queries the refcount btree about the\nwrong physical blocks and returns an inaccurate value in *shared.\n\nIf *shared is now false, the directio write proceeds with a stale data\nfork mapping.  Fix this by querying the data fork mapping if the\nsequence counter changes across the ILOCK cycle.","modified":"2026-07-25T03:47:47.129397017Z","published":"2026-07-23T05:46:56.149Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64600.json"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/07/22/14"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/07/22/18"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/07/22/19"},{"type":"WEB","url":"https://git.kernel.org/stable/c/206c09b04dc5469c7ff14d8aceff2d47c88078d9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/44f891bc088958399eec27f7604928694aa35581"},{"type":"WEB","url":"https://git.kernel.org/stable/c/50f0012da1040f69a4e788cd9aed587c9a04983f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b8c9aa832b52680ee40d6cab0efb081f9a69df05"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dc11be133efca5fe3a2fb02b016dee825cc12f18"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e705d81a7193dd19e69b8e2bad4696d78a4ea075"},{"type":"ADVISORY","url":"https://cdn2.qualys.com/advisory/2026/07/22/RefluXFS.txt"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64600.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64600"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5"},{"fixed":"dc11be133efca5fe3a2fb02b016dee825cc12f18"},{"fixed":"b8c9aa832b52680ee40d6cab0efb081f9a69df05"},{"fixed":"50f0012da1040f69a4e788cd9aed587c9a04983f"},{"fixed":"e705d81a7193dd19e69b8e2bad4696d78a4ea075"},{"fixed":"206c09b04dc5469c7ff14d8aceff2d47c88078d9"},{"fixed":"44f891bc088958399eec27f7604928694aa35581"},{"fixed":"2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64600.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.11.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.96"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.39"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64600.json"}}],"schema_version":"1.7.5"}