CVE-2026-46013mm/memfd_luo: fix physical address conversion in put_folios cleanup

Official description

In the Linux kernel, the following vulnerability has been resolved: mm/memfd_luo: fix physical address conversion in put_folios cleanup In memfd_luo_retrieve_folios()'s put_folios cleanup path: 1. kho_restore_folio() expects a phys_addr_t (physical address) but receives a raw PFN (pfolio->pfn). This causes kho_restore_page() to check the wrong physical address (pfn << PAGE_SHIFT instead of the actual physical address). 2. This loop lacks the !pfolio->pfn check that exists in the main retrieval loop and memfd_luo_discard_folios(), which could incorrectly process sparse file holes where pfn=0. Fix by converting PFN to physical address with PFN_PHYS() and adding the !pfolio->pfn check, matching the pattern used elsewhere in this file. This issue was identified by the AI review. https://sashiko.dev/#/patchset/20260323110747.193569-1-duanchenghao@kylinos.cn

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/bd0d6bde286a2b8e3ae7975b0dcc2d43875d5fc9
• https://git.kernel.org/stable/c/3538f90ab89aaf302782b4b073a0aae66904cd67