mm/hugetlb: fix folio is still mapped when deleted

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-40006
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-10-20 16:15:37 UTC
Updated2026-07-30 06:24:05 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix folio is still mapped when deleted Migration may be raced with fallocating hole. remove_inode_single_folio will unmap the folio if the folio is still mapped. However, it's called without folio lock. If the folio is migrated and the mapped pte has been converted to migration entry, folio_mapped() returns false, and won't unmap it. Due to extra refcount held by remove_inode_single_folio, migration fails, restores migration entry to normal pte, and the folio is mapped again. As a result, we triggered BUG in filemap_unaccount_folio. The log is as follows: BUG: Bad page cache in process hugetlb pfn:156c00 page: refcount:515 mapcount:0 mapping:0000000099fef6e1 index:0x0 pfn:0x156c00 head: order:9 mapcount:1 entire_mapcount:1 nr_pages_mapped:0 pincount:0 aops:hugetlbfs_aops ino:dcc dentry name(?):"my_hugepage_file" flags: 0x17ffffc00000c1(locked|waiters|head|node=0|zone=2|lastcpupid=0x1fffff) page_type: f4(hugetlb) page dumped because: still mapped when deleted CPU: 1 UID: 0 PID: 395 Comm: hugetlb Not tainted 6.17.0-rc5-00044-g7aac71907bde-dirty #484 NONE Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Call Trace: <TASK> dump_stack_lvl+0x4f/0x70 filemap_unaccount_folio+0xc4/0x1c0 __filemap_remove_folio+0x38/0x1c0 filemap_remove_folio+0x41/0xd0 remove_inode_hugepages+0x142/0x250 hugetlbfs_fallocate+0x471/0x5a0 vfs_fallocate+0x149/0x380 Hold folio lock before checking if the folio is mapped to avold race with migration.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.001880000 probability, percentile 0.087250000 (date 2026-07-31)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 bc1c9ce8aeff45318332035dbef9713fb9e982d7 git Not specified
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 91f548e920fbf8be3f285bfa3fa045ae017e836d git Not specified
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 3e851448078f5b01f6264915df3cfef75e323a12 git Not specified
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 c1dc0524ab2cc3982d4e0d2bfac71a0cd4d65c39 git Not specified
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 c9c2a51f91aea70e89b496cac360cd795a2b3c26 git Not specified
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 910d7749346c4b0acdc6e4adfdc4a9984281a206 git Not specified
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 21ee79ce938127f88fe07e409c1817f477dbe7ea git Not specified
CNA Linux Linux affected 4aae8d1c051ea00b456da6811bc36d1f69de5445 7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7 git Not specified
CNA Linux Linux affected 4.5 Not specified
CNA Linux Linux unaffected 4.5 semver Not specified
CNA Linux Linux unaffected 5.4.300 5.4.* semver Not specified
CNA Linux Linux unaffected 5.10.245 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.194 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.155 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.109 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.50 6.12.* semver Not specified
CNA Linux Linux unaffected 6.16.10 6.16.* semver Not specified
CNA Linux Linux unaffected 6.17 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/3e851448078f5b01f6264915df3cfef75e323a12 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/bc1c9ce8aeff45318332035dbef9713fb9e982d7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/c1dc0524ab2cc3982d4e0d2bfac71a0cd4d65c39 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/910d7749346c4b0acdc6e4adfdc4a9984281a206 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/91f548e920fbf8be3f285bfa3fa045ae017e836d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/21ee79ce938127f88fe07e409c1817f477dbe7ea 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/c9c2a51f91aea70e89b496cac360cd795a2b3c26 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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