CVE-2025-39899
- Source
- https://cve.org/CVERecord?id=CVE-2025-39899
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39899.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2025-39899
- Downstream
- Published
- 2025-10-01T07:42:47.100Z
- Modified
- 2026-01-15T03:10:54.682394Z
- Severity
-
- 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
mm/userfaultfd: fix kmaplocal LIFO ordering for CONFIGHIGHPTE
With CONFIGHIGHPTE on 32-bit ARM, movepagespte() maps PTE pages using kmaplocal_page(), which requires unmapping in Last-In-First-Out order.
The current code maps dstpte first, then srcpte, but unmaps them in the same order (dstpte, srcpte), violating the LIFO requirement. This causes the warning in kunmaplocalindexed():
WARNING: CPU: 0 PID: 604 at mm/highmem.c:622 kunmaplocalindexed+0x178/0x17c addr != _fixtovirt(FIXKMAP_BEGIN + idx)
Fix this by reversing the unmap order to respect LIFO ordering.
This issue follows the same pattern as similar fixes: - commit eca6828403b8 ("crypto: skcipher - fix mismatch between mapping and unmapping order") - commit 8cf57c6df818 ("nilfs2: eliminate staggered calls to kunmap in nilfs_rename")
Both of which addressed the same fundamental requirement that kmap_local operations must follow LIFO ordering.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39899.json" }- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/9614d8bee66387501f48718fa306e17f2aa3f2f3
- https://git.kernel.org/stable/c/b051f707018967ea8f697d790a1ed8c443f63812
- https://git.kernel.org/stable/c/bd1ee62759d0bd4d6b909731c076c230ac89d61e
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39899.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-39899
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
-
Introducedadef440691bab824e39c1b17382322d195e1fab0Fixedb051f707018967ea8f697d790a1ed8c443f63812Fixedbd1ee62759d0bd4d6b909731c076c230ac89d61eFixed9614d8bee66387501f48718fa306e17f2aa3f2f3