{"id":"CVE-2022-49554","summary":"zsmalloc: fix races between asynchronous zspage free and page migration","details":"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.","modified":"2026-04-02T08:27:42.706578Z","published":"2025-02-26T02:14:02.649Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49554.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2505a981114dcb715f8977b8433f7540854851d8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3674d8a8dadd03a447dd21069d4dacfc3399b63b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3ec459c8810e658401be428d3168eacfc380bdd0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/645996efc2ae391246d595832aaa6f9d3cc338c7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8ba7b7c1dad1f6503c541778f31b33f7f62eb966"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c5402fb5f71f1a725f1e55d9c6799c0c7bec308f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fae05b2314b147a78fbed1dc4c645d9a66313758"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fc658c083904427abbf8f18280d517ee2668677c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49554.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-49554"},{"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":"77ff465799c60294e248000cd22ae8171da3304c"},{"fixed":"3674d8a8dadd03a447dd21069d4dacfc3399b63b"},{"fixed":"645996efc2ae391246d595832aaa6f9d3cc338c7"},{"fixed":"fc658c083904427abbf8f18280d517ee2668677c"},{"fixed":"fae05b2314b147a78fbed1dc4c645d9a66313758"},{"fixed":"3ec459c8810e658401be428d3168eacfc380bdd0"},{"fixed":"8ba7b7c1dad1f6503c541778f31b33f7f62eb966"},{"fixed":"c5402fb5f71f1a725f1e55d9c6799c0c7bec308f"},{"fixed":"2505a981114dcb715f8977b8433f7540854851d8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49554.json"}}],"schema_version":"1.7.5"}