CVE-2022-49554
zsmalloc: fix races between asynchronous zspage free and page migration
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: zsmalloc: fix races between asynchronous zspage free and page migration The asynchronous zspage free worker tries to lock a zspage's entire page list without defending against page migration. Since pages which haven't yet been locked can concurrently migrate off the zspage page list while lock_zspage() churns away, lock_zspage() can suffer from a few different lethal races. It can lock a page which no longer belongs to the zspage and unsafely dereference page_private(), it can unsafely dereference a torn pointer to the next page (since there's a data race), and it can observe a spurious NULL pointer to the next page and thus not lock all of the zspage's pages (since a single page migration will reconstruct the entire page list, and create_page_chain() unconditionally zeroes out each list pointer in the process). Fix the races by using migrate_read_lock() in lock_zspage() to synchronize with page migration.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium4.7 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.22% · top 88% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 77ff465799c60294e248000cd22ae8171da3304c – < 3674d8a8dadd03a447dd21069d4dacfc3399b63b
- affected 77ff465799c60294e248000cd22ae8171da3304c – < 645996efc2ae391246d595832aaa6f9d3cc338c7
- affected 77ff465799c60294e248000cd22ae8171da3304c – < fc658c083904427abbf8f18280d517ee2668677c
- affected 77ff465799c60294e248000cd22ae8171da3304c – < fae05b2314b147a78fbed1dc4c645d9a66313758
- affected 77ff465799c60294e248000cd22ae8171da3304c – < 3ec459c8810e658401be428d3168eacfc380bdd0
- affected 77ff465799c60294e248000cd22ae8171da3304c – < 8ba7b7c1dad1f6503c541778f31b33f7f62eb966
- affected 77ff465799c60294e248000cd22ae8171da3304c – < c5402fb5f71f1a725f1e55d9c6799c0c7bec308f
- affected 77ff465799c60294e248000cd22ae8171da3304c – < 2505a981114dcb715f8977b8433f7540854851d8
- affected 4.14
- unaffected < 4.14
- unaffected 4.14.282 – ≤ 4.14.*
- unaffected 4.19.246 – ≤ 4.19.*
- unaffected 5.4.197 – ≤ 5.4.*
- unaffected 5.10.120 – ≤ 5.10.*
- unaffected 5.15.45 – ≤ 5.15.*
- unaffected 5.17.13 – ≤ 5.17.*
- unaffected 5.18.2 – ≤ 5.18.*
- unaffected 5.19 – ≤ *
References (8)
- https://git.kernel.org/stable/c/3674d8a8dadd03a447dd21069d4dacfc3399b63b (opens in a new tab)
- https://git.kernel.org/stable/c/645996efc2ae391246d595832aaa6f9d3cc338c7 (opens in a new tab)
- https://git.kernel.org/stable/c/fc658c083904427abbf8f18280d517ee2668677c (opens in a new tab)
- https://git.kernel.org/stable/c/fae05b2314b147a78fbed1dc4c645d9a66313758 (opens in a new tab)
- https://git.kernel.org/stable/c/3ec459c8810e658401be428d3168eacfc380bdd0 (opens in a new tab)
- https://git.kernel.org/stable/c/8ba7b7c1dad1f6503c541778f31b33f7f62eb966 (opens in a new tab)
- https://git.kernel.org/stable/c/c5402fb5f71f1a725f1e55d9c6799c0c7bec308f (opens in a new tab)
- https://git.kernel.org/stable/c/2505a981114dcb715f8977b8433f7540854851d8 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2022-49554)Record last updated .