{"cve":"CVE-2025-21853","nvd":{"published":"2025-03-12T10:15:18.063","modified":"2026-10-15T02:17:38.630","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: avoid holding freeze_mutex during mmap operation\n\nWe use map->freeze_mutex to prevent races between map_freeze() and\nmemory mapping BPF map contents with writable permissions. The way we\nnaively do this means we'll hold freeze_mutex for entire duration of all\nthe mm and VMA manipulations, which is completely unnecessary. This can\npotentially also lead to deadlocks, as reported by syzbot in [0].\n\nSo, instead, hold freeze_mutex only during writeability checks, bump\n(proactively) \"write active\" count for the map, unlock the mutex and\nproceed with mmap logic. And only if something went wrong during mmap\nlogic, then undo that \"write active\" counter increment.\n\n  [0] https://lore.kernel.org/bpf/678dcbc9.050a0220.303755.0066.GAE@google.com/","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0d90d9e154144a3a80e9fc0eb9b21b7fc990f68f","https://git.kernel.org/stable/c/271e49f8a58edba65bc2b1250a0abaa98c4bfdbe","https://git.kernel.org/stable/c/29cfda62ab4d92ab94123813db49ab76c1e61b29","https://git.kernel.org/stable/c/2ce31c97c219b4fe797749f950274f246eb88c49","https://git.kernel.org/stable/c/4759acbd44d24a69b7b14848012ec4201d6c5501"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:17.429720821+00:00"},"epss":{"cve":"CVE-2025-21853","score":0.00248,"percentile":0.16001,"date":"2026-10-26"},"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."]}