Bug 2492428 (CVE-2026-53056)

Summary: CVE-2026-53056 kernel: drm/msm/dpu: fix mismatch between power and frequency
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's Display Processing Unit (DPU) driver. During DPU runtime suspend, a mismatch can occur between the power rail voltage and the core clock frequency. This happens when the power management attempts to drop the voltage while the clock remains at its highest rate. This inconsistency can lead to system instability or a crash, effectively causing a Denial of Service (DoS).
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-06-24 18:11:32 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/msm/dpu: fix mismatch between power and frequency

During DPU runtime suspend, calling dev_pm_opp_set_rate(dev, 0) drops
the MMCX rail to MIN_SVS while the core clock frequency remains at its
original (highest) rate. When runtime resume re-enables the clock, this
may result in a mismatch between the rail voltage and the clock rate.

For example, in the DPU bind path, the sequence could be:
  cpu0: dev_sync_state -> rpmhpd_sync_state
  cpu1:                                     dpu_kms_hw_init
timeline 0 ------------------------------------------------> t

After rpmhpd_sync_state, the voltage performance is no longer guaranteed
to stay at the highest level. During dpu_kms_hw_init, calling
dev_pm_opp_set_rate(dev, 0) drops the voltage, causing the MMCX rail to
fall to MIN_SVS while the core clock is still at its maximum frequency.
When the power is re-enabled, only the clock is enabled, leading to a
situation where the MMCX rail is at MIN_SVS but the core clock is at its
highest rate. In this state, the rail cannot sustain the clock rate,
which may cause instability or system crash.

Remove the call to dev_pm_opp_set_rate(dev, 0) from dpu_runtime_suspend
to ensure the correct vote is restored when DPU resumes.

Patchwork: https://patchwork.freedesktop.org/patch/710077/
Comment 1 Mauro Matteo Cascella 2026-06-26 11:43:07 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062401-CVE-2026-53056-973a@gregkh/T