5.5

CVE-2025-37958: mm/huge_memory: fix dereferencing invalid pmd migration entry

Analyzed
AliasesUBUNTU-CVE-2025-37958DEBIAN-CVE-2025-37958
Published 20-05-2025Last modified 11-05-2026

Vulnerability summary

CVE-2025-37958 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in debian debian_linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.23%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 58 · Related 48
DLA-4327-1DLA-4328-1DSA-5973-1RHSA-2025:11428RHSA-2025:11861RHSA-2025:12209

Timeline

  1. 20-05-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: fix dereferencing invalid pmd migration entry When migrating a THP, concurrent access to the PMD migration entry during a deferred split scan can lead to an invalid address access, as illustrated below. To prevent this invalid access, it is necessary to check the PMD migration entry and return early. In this context, there is no need to use pmd_to_swp_entry and pfn_swap_entry_to_page to verify the equality of the target folio. Since the PMD migration entry is locked, it cannot be served as the target. Mailing list discussion and explanation from Hugh Dickins: "An anon_vma lookup points to a location which may contain the folio of interest, but might instead contain another folio: and weeding out those other folios is precisely what the "folio != pmd_folio((*pmd)" check (and the "risk of replacing the wrong folio" comment a few lines above it) is for." BUG: unable to handle page fault for address: ffffea60001db008 CPU: 0 UID: 0 PID: 2199114 Comm: tee Not tainted 6.14.0+ #4 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:split_huge_pmd_locked+0x3b5/0x2b60 Call Trace: <TASK> try_to_migrate_one+0x28c/0x3730 rmap_walk_anon+0x4f6/0x770 unmap_folio+0x196/0x1f0 split_huge_page_to_list_to_order+0x9f6/0x1560 deferred_split_scan+0xac5/0x12a0 shrinker_debugfs_scan_write+0x376/0x470 full_proxy_write+0x15c/0x220 vfs_write+0x2fc/0xcb0 ksys_write+0x146/0x250 do_syscall_64+0x6a/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e The bug is found by syzkaller on an internal kernel, then confirmed on upstream.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

14%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.22% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu143 products
  • linux< 4.15.0-245.257 | < 5.4.0-224.244 | < 5.15.0-156.166 | < 6.8.0-90.91
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.15.0-1187.200 | < 5.4.0-1153.163 | < 5.15.0-1092.99 | < 6.8.0-1044.46
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
Linux2 products
  • linux≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < 753f142f7ff7d2223a47105b61e1efd91587d711 | ≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < 9468afbda3fbfcec21ac8132364dff3dab945faf | ≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < ef5706bed97e240b4abf4233ceb03da7336bc775 | ≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < 22f6368768340260e862f35151d2e1c55cb1dc75 | ≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < 3977946f61cdba87b6b5aaf7d7094e96089583a5 | ≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < 6166c3cf405441f7147b322980144feb3cefc617 | ≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < fbab262b0c8226c697af1851a424896ed47dedcc | ≥ 84c3fc4e9c563d8fb91cfdf5948da48fe1af34d3, < be6e843fc51a584672dfd9c4a6a24c8cb81d5fb7 | 4.14
  • linux_kernel≥ 4.14, < 5.4.295 | ≥ 5.5, < 5.10.239 | ≥ 5.11, < 5.15.186 | ≥ 5.16, < 6.1.142 | ≥ 6.2, < 6.6.95 | ≥ 6.7, < 6.12.29 | ≥ 6.13, < 6.14.7 | 6.15:rc1 | 6.15:rc2 | 6.15:rc3 | 6.15:rc4 | 6.15:rc5

3 vendors · 147 products

References

48 links
Show all 48 references