Bug 2461438 (CVE-2026-31572)

Summary: CVE-2026-31572 kernel: i2c: designware: amdisp: Fix resume-probe race condition issue
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
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 `i2c: designware: amdisp` component. A race condition exists between the device's probe and runtime Power Management (PM) resume operations. When `pm_runtime_get_sync()` is called before `i2c_dw_probe()`, it can prematurely trigger the `amdisp` i2c runtime resume before the device's probe process is complete. This timing issue can lead to a NULL dereferencing error, potentially causing system instability or a denial of service.
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 2026-04-24 15:01:31 UTC
In the Linux kernel, the following vulnerability has been resolved:

i2c: designware: amdisp: Fix resume-probe race condition issue

Identified resume-probe race condition in kernel v7.0 with the commit
38fa29b01a6a ("i2c: designware: Combine the init functions"),but this
issue existed from the beginning though not detected.

The amdisp i2c device requires ISP to be in power-on state for probe
to succeed. To meet this requirement, this device is added to genpd
to control ISP power using runtime PM. The pm_runtime_get_sync() called
before i2c_dw_probe() triggers PM resume, which powers on ISP and also
invokes the amdisp i2c runtime resume before the probe completes resulting
in this race condition and a NULL dereferencing issue in v7.0

Fix this race condition by using the genpd APIs directly during probe:
  - Call dev_pm_genpd_resume() to Power ON ISP before probe
  - Call dev_pm_genpd_suspend() to Power OFF ISP after probe
  - Set the device to suspended state with pm_runtime_set_suspended()
  - Enable runtime PM only after the device is fully initialized