CVE-2025-22015
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2025-22015
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-22015.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2025-22015
- Downstream
- Related
- Published
- 2025-04-08T08:18:05Z
- Modified
- 2025-10-14T20:25:27.586830Z
- Summary
- mm/migrate: fix shmem xarray update during migration
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
mm/migrate: fix shmem xarray update during migration
A shmem folio can be either in page cache or in swap cache, but not at the same time. Namely, once it is in swap cache, folio->mapping should be NULL, and the folio is no longer in a shmem mapping.
In _foliomigratemapping(), to determine the number of xarray entries to update, foliotestswapbacked() is used, but that conflates shmem in page cache case and shmem in swap cache case. It leads to xarray multi-index entry corruption, since it turns a sibling entry to a normal entry during xasstore() (see [1] for a userspace reproduction). Fix it by only using foliotestswapcache() to determine whether xarray is storing swap cache entries or not to choose the right number of xarray entries to update.
[1] https://lore.kernel.org/linux-mm/Z8idPCkaJW1IChjT@casper.infradead.org/
Note: In _splithugepage(), foliotestanon() && foliotestswapcache() is used to get swapcache address space, but that ignores the shmem folio in swap cache case. It could lead to NULL pointer dereferencing when a in-swap-cache shmem folio is split at _xastore(), since !foliotestanon() is true and folio->mapping is NULL. But fortunately, its caller splithugepagetolisttoorder() bails out early with EBUSY when folio->mapping is NULL. So no need to take care of it here.
- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/29124ae980e2860f0eec7355949d3d3292ee81da
- https://git.kernel.org/stable/c/49100c0b070e900f87c8fac3be9b9ef8a30fa673
- https://git.kernel.org/stable/c/60cf233b585cdf1f3c5e52d1225606b86acd08b0
- https://git.kernel.org/stable/c/75cfb92eb63298d717b6b0118f91ba12c4fcfeb5
- https://git.kernel.org/stable/c/c057ee03f751d6cecf7ee64f52f6545d94082aaa
Affected packages
Git / 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
-
Introducedbe72d197b2281e2ee3f28017fc9be1ab17e26d16Fixed49100c0b070e900f87c8fac3be9b9ef8a30fa673
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced07550b1461d4d0499165e7d6f7718cfd0e440427Fixed29124ae980e2860f0eec7355949d3d3292ee81da
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedfc346d0a70a13d52fe1c4bc49516d83a42cd7c4cFixedc057ee03f751d6cecf7ee64f52f6545d94082aaa
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedfc346d0a70a13d52fe1c4bc49516d83a42cd7c4cFixed75cfb92eb63298d717b6b0118f91ba12c4fcfeb5
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedfc346d0a70a13d52fe1c4bc49516d83a42cd7c4cFixed60cf233b585cdf1f3c5e52d1225606b86acd08b0