{"cve":"CVE-2026-89644","nvd":{"published":"2026-09-11T20:19:50.223","modified":"2026-10-21T13:20:14.630","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix extent map leak in NOCOW direct I/O write\n\nbtrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an\nextent map reference that must be dropped on all exit paths.\n\nFor direct writes into a NOCOW range, btrfs_get_blocks_direct_write()\nkeeps using that extent map and asks btrfs_create_dio_extent() to\nallocate the ordered extent. If that fails, for example because\nbtrfs_alloc_ordered_extent() fails, the function returns the error\nwithout dropping the input extent map. The PREALLOC path avoided this by\ndropping the input extent map before replacing it with the newly created\none.\n\nCheck the error from btrfs_create_dio_extent() before replacing the\nmap and drop the input extent map on failure.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d","https://git.kernel.org/stable/c/3f950867c307c5413d628a153ac44915bd117ffd","https://git.kernel.org/stable/c/b7c873765875645b11503f94c9bae2ca80127375","https://git.kernel.org/stable/c/cb732d302245b14943a5017015fffa8e6db7a6c0","https://git.kernel.org/stable/c/f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-89644","score":0.00168,"percentile":0.06161,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}