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CVE Record

CVE-2025-21849: drm/i915/gt: Use spin_lock_irqsave() in interruptible context

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gt: Use spin_lock_irqsave() in interruptible context spin_lock/unlock() functions used in interrupt contexts could result in a deadlock, as seen in GitLab issue #13399, which occurs when interrupt comes in while holding a lock. Try to remedy the problem by saving irq state before spin lock acquisition. v2: add irqs' state save/restore calls to all locks/unlocks in signal_irq_work() execution (Maciej) v3: use with spin_lock_irqsave() in guc_lrc_desc_unpin() instead of other lock/unlock calls and add Fixes and Cc tags (Tvrtko); change title and commit message (cherry picked from commit c088387ddd6482b40f21ccf23db1125e8fa4af7e)

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel availability flaw in the Intel i915 graphics driver. A local user with access to an affected system could trigger a driver deadlock, potentially hanging GPU-related work or affecting system availability. It does not indicate data theft or privilege escalation in the provided sources.

Executive priority

Treat as a moderate availability risk. Patch through the normal kernel maintenance process, with faster handling for shared endpoints, developer workstations, and systems where local users are less trusted.

Technical view

The issue is improper lock handling in drm/i915/gt. spin_lock/unlock were used in interruptible contexts, so an interrupt arriving while a lock was held could deadlock. The upstream fix changes the relevant paths to save and restore interrupt state around spin lock acquisition.

Likely exposure

Exposure is mainly Linux systems running affected kernel versions with the Intel i915 graphics driver path present. Highest concern is shared workstations, desktop fleets, CI hosts, or systems where untrusted local users can run workloads that exercise Intel GPU functionality.

Exploitation context

The CVSS vector is local, low complexity, low privileges, no user interaction, and high availability impact. The source bundle does not cite public exploitation, and KEV status is false, so active exploitation is not established here.

Researcher notes

The provided record ties the bug to CWE-667 and a deadlock in signal_irq_work-related i915/Guc locking. Evidence supports availability impact only. Affected-version data is kernel-focused and should be reconciled with distribution backports before declaring systems vulnerable.

Mitigation direction

  • Apply Linux kernel updates that include the referenced stable fixes.
  • Check distribution or vendor advisories for backported fixed kernel packages.
  • Prioritize shared systems where local users can exercise Intel i915 GPU paths.
  • Plan required reboots after kernel updates.
  • If no update is available, follow vendor guidance for interim controls.

Validation and detection

  • Inventory Linux kernel versions across systems using Intel graphics hardware.
  • Confirm installed kernel packages include the CVE fix or referenced stable commits.
  • Check whether the i915 driver is present or active on candidate systems.
  • Review vendor changelogs for CVE-2025-21849 or the i915 spin_lock_irqsave fix.
  • After updating, monitor for recurring GPU hangs or deadlock symptoms.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-667: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2025-21849 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
1ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2025-21849Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux2f2cc53b5fe7022f3ae602eb24573d52f8740959, 2f2cc53b5fe7022f3ae602eb24573d52f8740959, 2f2cc53b5fe7022f3ae602eb24573d52f8740959unaffected
LinuxLinux6.9, 0, 6.12.17, 6.13.5, 6.14affected
Weakness

CWE details

CWE-667

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.