CVE-2026-23467

What it is

In the Linux kernel, the following vulnerability has been resolved: drm/i915/dmc: Fix an unlikely NULL pointer deference at probe intel_dmc_update_dc6_allowed_count() oopses when DMC hasn't been initialized, and dmc is thus NULL. That would be the case when the call path is intel_power_domains_init_hw() -> {skl,bxt,icl}_display_core_init() -> gen9_set_dc_state() -> intel_dmc_update_dc6_allowed_count(), as intel_power_domains_init_hw() is called *before* intel_dmc_init(). However, gen9_set_dc_state() calls intel_dmc_update_dc6_allowed_count() conditionally, depending on the current and target DC states. At probe, the target is disabled, but if DC6 is enabled, the function is called, and an oops follows. Apparently it's quite unlikely that DC6 is enabled at probe, as we haven't seen this failure mode before. It is also strange to have DC6 enabled at boot, since that would require the DMC firmware (loaded by BIOS); the BIOS loading the DMC firmware and the driver stopping / reprogramming the firmware is a poorly specified sequence and as such unlikely an intentional BIOS behaviour. It's more likely that BIOS is leaving an unintentionally enabled DC6 HW state behind (without actually loading the required DMC firmware for this). The tracking of the DC6 allowed counter only works if starting / stopping the counter depends on the _SW_ DC6 state vs. the current _HW_ DC6 state (since stopping the counter requires the DC5 counter captured when the counter was started). Thus, using the HW DC6 state is incorrect and it also leads to the above oops. Fix both issues by using the SW DC6 state for the tracking. This is v2 of the fix originally sent by Jani, updated based on the first Link: discussion below. (cherry picked from commit 2344b93af8eb5da5d496b4e0529d35f0f559eaf0)

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-04-03 16:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-11-05 22:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-04-03 16:16 UTC

Last modified

2026-11-05 22:18 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-476 · NULL pointer dereference

Record status

Analyzed

Affected

• Linux Kernel < 6.18.20
• Linux Kernel < 6.19.10
• Linux Kernel 7.0

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-23467.md and follow it. Check whether this project is affected by CVE-2026-23467. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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