cve.bz

CVE-2022-49554

4.7 mediumEPSS 0.2%

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
4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-25)
CWE
CWE-362
Published
Modified
Record from
the NVD, synced

Affected

References

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