CVE-2025-37958

MEDIUM EPSS 6.2%
Published May 20, 20251y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published May 20, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
6.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 13

VendorProductVersionRange
linuxlinux_kernel*≥4.14  –  <5.4.295
linuxlinux_kernel*≥5.5  –  <5.10.239
linuxlinux_kernel*≥5.11  –  <5.15.186
linuxlinux_kernel*≥5.16  –  <6.1.142
linuxlinux_kernel*≥6.2  –  <6.6.95
linuxlinux_kernel*≥6.7  –  <6.12.29
linuxlinux_kernel*≥6.13  –  <6.14.7
linuxlinux_kernel6.15any
linuxlinux_kernel6.15any
linuxlinux_kernel6.15any
linuxlinux_kernel6.15any
linuxlinux_kernel6.15any
debiandebian_linux11.0any

References 10

  • git.kernel.org https://git.kernel.org/stable/c/22f6368768340260e862f35151d2e1c55cb1dc75
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3977946f61cdba87b6b5aaf7d7094e96089583a5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6166c3cf405441f7147b322980144feb3cefc617
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/753f142f7ff7d2223a47105b61e1efd91587d711
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9468afbda3fbfcec21ac8132364dff3dab945faf
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/be6e843fc51a584672dfd9c4a6a24c8cb81d5fb7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ef5706bed97e240b4abf4233ceb03da7336bc775
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fbab262b0c8226c697af1851a424896ed47dedcc
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
    Third Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
    Third Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/22f6368768340260e862f35151d2e1c55cb1dc75
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3977946f61cdba87b6b5aaf7d7094e96089583a5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6166c3cf405441f7147b322980144feb3cefc617
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/753f142f7ff7d2223a47105b61e1efd91587d711
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9468afbda3fbfcec21ac8132364dff3dab945faf
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/be6e843fc51a584672dfd9c4a6a24c8cb81d5fb7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ef5706bed97e240b4abf4233ceb03da7336bc775
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fbab262b0c8226c697af1851a424896ed47dedcc
    Patch