VulnerabilityPublished 8 May 2025Updated 14 Nov 2025

CVE-2025-37834: Linux kernel · mm/vmscan: don't try to reclaim hwpoison folio

Source GCVE Database

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Authoritative record:CVE-2025-37834· High

Not known to be exploited · CVSS 5.5 High.

Data as of 13 Nov 2026, 18:57 UTC

CVSS 3.1 base score

5.5High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

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

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 May 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-jmf7-45hm-82v2

What to do

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel by modifying the reclaim logic to skip hardware-poisoned pages and properly unmap them during memory reclaim. Users should update to a kernel version that includes this fix. No other mitigation or workaround is indicated.

Description

CVE-2025-37834 is a vulnerability in the Linux kernel's memory management subsystem where the kernel attempts to reclaim hardware-poisoned memory pages (hwpoison folios) improperly. This can lead to a kernel BUG and system crash (Oops) due to incorrect handling of dirty swapcache pages that are hardware poisoned. The issue arises when the kernel tries to reclaim such pages, which are not properly unmapped and remain in the least recently used (LRU) list indefinitely, causing a failure in the reclaim process.

Impact

The vulnerability can cause a kernel crash (Oops) leading to denial of service on affected Linux systems. It does not impact confidentiality or integrity but affects availability due to system instability. The CVSS score is 5.5 (medium severity) with local attack vector, low complexity, and requires low privileges. There is no indication of exploitation in the wild.

Summary

This vulnerability involves the Linux kernel's memory reclaim code in mm/vmscan. When a dirty swapcache page is hardware poisoned and isolated by the reclaim process, the page's uptodate flag is cleared but the page remains referenced and is put back into the LRU list. If the process mapping the hwpoisoned page exits, the page is deleted but never freed, remaining in the LRU list forever. Subsequent reclaim attempts trigger a kernel BUG due to the cleared uptodate flag. The fix involves skipping hwpoisoned pages during the shrink_folio_list() reclaim process and ensuring such pages are unmapped properly to prevent them from lingering in the LRU list.

References

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