Bug 2482087 (CVE-2026-46013)

Summary: CVE-2026-46013 kernel: mm/memfd_luo: fix physical address conversion in put_folios cleanup
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: unspecified    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel. An issue in the `memfd_luo` component, specifically within the `put_folios` cleanup path of `memfd_luo_retrieve_folios()`, leads to incorrect physical address conversion and a missing check for sparse file holes. This could result in incorrect memory handling, potentially causing system instability or unexpected behavior.
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Description OSIDB Bzimport 2026-05-27 15:10:42 UTC 
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
Comment 1 Keith Grant 2026-05-27 20:48:02 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052745-CVE-2026-46013-3562@gregkh/T