In the Linux kernel, the following vulnerability has been resolved:

block: add pgmap check to biovec_phys_mergeable

biovec_phys_mergeable() is used by the request merge, DMA mapping,
and integrity merge paths to decide if two physically contiguous
bvec segments can be coalesced into one. It currently has no check
for whether the segments belong to different dev_pagemaps.

When zone device memory is registered in multiple chunks, each chunk
gets its own dev_pagemap. A single bio can legitimately contain
bvecs from different pgmaps -- iov_iter_extract_bvecs() breaks at
pgmap boundaries but the outer loop in bio_iov_iter_get_pages()
continues filling the same bio. If such bvecs are physically
contiguous, biovec_phys_mergeable() will coalesce them, making it
impossible to recover the correct pgmap for the merged segment
via page_pgmap().

Add a zone_device_pages_have_same_pgmap() check to prevent merging
bvec segments that span different pgmaps.

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History

Thu, 28 May 2026 11:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-285
CWE-456

Thu, 28 May 2026 10:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: block: add pgmap check to biovec_phys_mergeable biovec_phys_mergeable() is used by the request merge, DMA mapping, and integrity merge paths to decide if two physically contiguous bvec segments can be coalesced into one. It currently has no check for whether the segments belong to different dev_pagemaps. When zone device memory is registered in multiple chunks, each chunk gets its own dev_pagemap. A single bio can legitimately contain bvecs from different pgmaps -- iov_iter_extract_bvecs() breaks at pgmap boundaries but the outer loop in bio_iov_iter_get_pages() continues filling the same bio. If such bvecs are physically contiguous, biovec_phys_mergeable() will coalesce them, making it impossible to recover the correct pgmap for the merged segment via page_pgmap(). Add a zone_device_pages_have_same_pgmap() check to prevent merging bvec segments that span different pgmaps.
Title block: add pgmap check to biovec_phys_mergeable
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-28T09:35:26.735Z

Reserved: 2026-05-13T15:03:33.098Z

Link: CVE-2026-46115

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-28T10:16:26.980

Modified: 2026-05-28T13:44:01.663

Link: CVE-2026-46115

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-28T12:15:19Z

Weaknesses