VulnerabilityPublished 19 Jul 2026

CVE-2026-64100: Linux kernel · drm/msm: Fix shrinker deadlock

Source GCVE Database

Not known to be exploited · CVSS 5.5 Medium.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score

5.5Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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-3q3c-q46p-rwcg

What to do

AI-suggested

A fix has been implemented in the Linux kernel to resolve this deadlock by modifying the locking mechanism in the drm/msm driver. Users should apply the official kernel update or patch that includes this fix. Since this is a kernel-level issue, upgrading to a kernel version containing the patch is the recommended remediation. Patch status is not explicitly confirmed in the provided data; check the vendor or kernel mailing list advisories for the exact fixed version and update accordingly.

Description

A deadlock vulnerability in the Linux kernel's drm/msm driver was resolved. The issue occurs with PROVE_LOCKING enabled on Snapdragon X1 platforms under VM reclaim pressure, causing a circular locking dependency involving reservation locks and fs_reclaim locks. This deadlock can cause kernel tasks to hang during memory reclaim operations. The fix replaces a blocking lock acquisition with a trylock to prevent the deadlock scenario.

Impact

The vulnerability can cause kernel deadlocks during memory reclaim operations on affected hardware, potentially leading to system hangs or degraded performance. There is no indication of privilege escalation or code execution impact. The issue is specific to certain kernel configurations and hardware (Snapdragon X1 with PROVE_LOCKING).

Summary

CVE-2026-64100 addresses a deadlock in the Linux kernel drm/msm driver related to the shrinker mechanism. Under certain conditions on Snapdragon X1 hardware with PROVE_LOCKING enabled, a circular locking dependency arises between reservation_ww_class_acquire, reservation_ww_class_mutex, and fs_reclaim locks. This deadlock manifests during VM reclaim pressure when kswapd0 holds fs_reclaim and attempts to acquire the MSM shrinker lock, which in turn tries to reacquire fs_reclaim, causing a circular wait. The patch changes the locking strategy by using dma_resv_trylock() instead of dma_resv_lock(), dropping the wait-wound lock ticket to break the deadlock chain.

References

Community reviews

Loading reviews…