{"cve":"CVE-2022-49554","nvd":{"published":"2025-02-26T07:01:31.223","modified":"2026-10-15T22:17:24.480","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nzsmalloc: fix races between asynchronous zspage free and page migration\n\nThe asynchronous zspage free worker tries to lock a zspage's entire page\nlist without defending against page migration.  Since pages which haven't\nyet been locked can concurrently migrate off the zspage page list while\nlock_zspage() churns away, lock_zspage() can suffer from a few different\nlethal races.\n\nIt can lock a page which no longer belongs to the zspage and unsafely\ndereference page_private(), it can unsafely dereference a torn pointer to\nthe next page (since there's a data race), and it can observe a spurious\nNULL pointer to the next page and thus not lock all of the zspage's pages\n(since a single page migration will reconstruct the entire page list, and\ncreate_page_chain() unconditionally zeroes out each list pointer in the\nprocess).\n\nFix the races by using migrate_read_lock() in lock_zspage() to synchronize\nwith page migration.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","score":4.7},"cwes":["CWE-362"],"references":["https://git.kernel.org/stable/c/2505a981114dcb715f8977b8433f7540854851d8","https://git.kernel.org/stable/c/3674d8a8dadd03a447dd21069d4dacfc3399b63b","https://git.kernel.org/stable/c/3ec459c8810e658401be428d3168eacfc380bdd0","https://git.kernel.org/stable/c/645996efc2ae391246d595832aaa6f9d3cc338c7","https://git.kernel.org/stable/c/8ba7b7c1dad1f6503c541778f31b33f7f62eb966"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2022-49554","score":0.00217,"percentile":0.1201,"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."]}