CVE-2022-49554
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…
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.7 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.22% probability · 12th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-362
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/2505a981114dcb715f8977b8433f7540854851d8Patch
- https://git.kernel.org/stable/c/3674d8a8dadd03a447dd21069d4dacfc3399b63bPatch
- https://git.kernel.org/stable/c/3ec459c8810e658401be428d3168eacfc380bdd0Patch
- https://git.kernel.org/stable/c/645996efc2ae391246d595832aaa6f9d3cc338c7Patch
- https://git.kernel.org/stable/c/8ba7b7c1dad1f6503c541778f31b33f7f62eb966Patch
- https://git.kernel.org/stable/c/c5402fb5f71f1a725f1e55d9c6799c0c7bec308fPatch
- https://git.kernel.org/stable/c/fae05b2314b147a78fbed1dc4c645d9a66313758Patch
- https://git.kernel.org/stable/c/fc658c083904427abbf8f18280d517ee2668677cPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.