Linux Kernel up to 6.12.22/6.13.10/6.14.1 gup PageTail reference count

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5.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.22/6.13.10/6.14.1. It has been classified as critical. Impacted is the function PageTail of the component gup. Performing a manipulation results in reference count. This vulnerability is cataloged as CVE-2025-22034. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.22/6.13.10/6.14.1. It has been classified as critical. This affects the function PageTail of the component gup. The manipulation with an unknown input leads to a reference count vulnerability. CWE is classifying the issue as CWE-911. The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: mm/gup: reject FOLL_SPLIT_PMD with hugetlb VMAs Patch series "mm: fixes for device-exclusive entries (hmm)", v2. Discussing the PageTail() call in make_device_exclusive_range() with Willy, I recently discovered [1] that device-exclusive handling does not properly work with THP, making the hmm-tests selftests fail if THPs are enabled on the system. Looking into more details, I found that hugetlb is not properly fenced, and I realized that something that was bugging me for longer -- how device-exclusive entries interact with mapcounts -- completely breaks migration/swapout/split/hwpoison handling of these folios while they have device-exclusive PTEs. The program below can be used to allocate 1 GiB worth of pages and making them device-exclusive on a kernel with CONFIG_TEST_HMM. Once they are device-exclusive, these folios cannot get swapped out (proc$pid/smaps_rollup will always indicate 1 GiB RSS no matter how much one forces memory reclaim), and when having a memory block onlined to ZONE_MOVABLE, trying to offline it will loop forever and complain about failed migration of a page that should be movable. # echo offline > /sys/devices/system/memory/memory136/state # echo online_movable > /sys/devices/system/memory/memory136/state # ./hmm-swap & ... wait until everything is device-exclusive # echo offline > /sys/devices/system/memory/memory136/state [ 285.193431][T14882] page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x7f20671f7 pfn:0x442b6a [ 285.196618][T14882] memcg:ffff888179298000 [ 285.198085][T14882] anon flags: 0x5fff0000002091c(referenced|uptodate| dirty|active|owner_2|swapbacked|node=1|zone=3|lastcpupid=0x7ff) [ 285.201734][T14882] raw: ... [ 285.204464][T14882] raw: ... [ 285.207196][T14882] page dumped because: migration failure [ 285.209072][T14882] page_owner tracks the page as allocated [ 285.210915][T14882] page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), id 14926, tgid 14926 (hmm-swap), ts 254506295376, free_ts 227402023774 [ 285.216765][T14882] post_alloc_hook+0x197/0x1b0 [ 285.218874][T14882] get_page_from_freelist+0x76e/0x3280 [ 285.220864][T14882] __alloc_frozen_pages_noprof+0x38e/0x2740 [ 285.223302][T14882] alloc_pages_mpol+0x1fc/0x540 [ 285.225130][T14882] folio_alloc_mpol_noprof+0x36/0x340 [ 285.227222][T14882] vma_alloc_folio_noprof+0xee/0x1a0 [ 285.229074][T14882] __handle_mm_fault+0x2b38/0x56a0 [ 285.230822][T14882] handle_mm_fault+0x368/0x9f0 ... This series fixes all issues I found so far. There is no easy way to fix without a bigger rework/cleanup. I have a bunch of cleanups on top (some previous sent, some the result of the discussion in v1) that I will send out separately once this landed and I get to it. I wish we could just use some special present PROT_NONE PTEs instead of these (non-present, non-none) fake-swap entries; but that just results in the same problem we keep having (lack of spare PTE bits), and staring at other similar fake-swap entries, that ship has sailed. With this series, make_device_exclusive() doesn't actually belong into mm/rmap.c anymore, but I'll leave moving that for another day. I only tested this series with the hmm-tests selftests due to lack of HW, so I'd appreciate some testing, especially if the interaction between two GPUs wanting a device-exclusive entry works as expected. <program> #include <stdio.h> #include <fcntl.h> #include <stdint.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <sys/mman.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/ioctl.h> #define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) struct hmm_dmirror_cmd { __u64 addr; __u64 ptr; __u64 npages; __u64 cpages; __u64 faults; }; const size_t size = 1 * 1024 * 1024 * 1024ul; const size_t chunk_size = 2 * 1024 * 1024ul; int m ---truncated---

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-22034 since 12/29/2024. The exploitability is told to be easy. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 240657 (Ubuntu 25.04 : Linux kernel vulnerabilities (USN-7594-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.23, 6.13.11, 6.14.2 or 6.15-rc1 eliminates this vulnerability. Applying the patch 2e877ff3492267def06dd50cb165dc9ab8838e7d/48d28417c66cce2f3b0ba773fcb6695a56eff220/fd900832e8440046627b60697687ab5d04398008/8977752c8056a6a094a279004a49722da15bace3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (240657) and CERT Bund (WID-SEC-2025-0844). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel
  • Dell Avamar
  • SolarWinds Security Event Manager
  • Dell NetWorker
  • Dell Secure Connect Gateway
  • IBM QRadar SIEM

Productinfo

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Reference count
CWE: CWE-911 / CWE-664
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 240657
Nessus Name: Ubuntu 25.04 : Linux kernel vulnerabilities (USN-7594-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.23/6.13.11/6.14.2/6.15-rc1
Patch: 2e877ff3492267def06dd50cb165dc9ab8838e7d/48d28417c66cce2f3b0ba773fcb6695a56eff220/fd900832e8440046627b60697687ab5d04398008/8977752c8056a6a094a279004a49722da15bace3

Timelineinfo

12/29/2024 CVE reserved
04/16/2025 +107 days Advisory disclosed
04/16/2025 +0 days VulDB entry created
02/15/2026 +305 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-22034 (🔒)
GCVE (CVE): GCVE-0-2025-22034
GCVE (VulDB): GCVE-100-305079
CERT Bund: WID-SEC-2025-0844 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 04/16/2025 17:11
Updated: 02/15/2026 01:31
Changes: 04/16/2025 17:11 (59), 06/28/2025 14:13 (2), 07/15/2025 00:42 (7), 10/09/2025 00:24 (1), 10/31/2025 21:47 (12), 02/15/2026 01:31 (1)
Complete: 🔍
Cache ID: 216:424:103

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