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CVE-2026-43477

In the Linux kernel, the following vulnerability has been resolved: drm/i915/vrr: Configure VRR timings after enabling TRANS_DDI_FUNC_CTL Apparently ICL may hang with…

Published May 13, 2026 · updated Jun 26, 2026 · linux linux kernel

In the Linux kernel, the following vulnerability has been resolved: drm/i915/vrr: Configure VRR timings after enabling TRANS_DDI_FUNC_CTL Apparently ICL may hang with an MCE if we write TRANS_VRR_VMAX/FLIPLINE before enabling TRANS_DDI_FUNC_CTL. Personally I was only able to reproduce a hang (on an Dell XPS 7390 2-in-1) with an external display connected via a dock using a dodgy type-C cable that made the link training fail. After the failed link training the machine would hang. TGL seemed immune to the problem for whatever reason. BSpec does tell us to configure VRR after enabling TRANS_DDI_FUNC_CTL as well. The DMC firmware also does the VRR restore in two stages: - first stage seems to be unconditional and includes TRANS_VRR_CTL and a few other VRR registers, among other things - second stage is conditional on the DDI being enabled, and includes TRANS_DDI_FUNC_CTL and TRANS_VRR_VMAX/VMIN/FLIPLINE, among other things So let's reorder the steps to match to avoid the hang, and toss in an extra WARN to make sure we don't screw this up later. BSpec: 22243 (cherry picked from commit 93f3a267c3dd4d811b224bb9e179a10d81456a74)

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 13, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: drm/i915/vrr: Configure VRR timings after enabling TRANS_DDI_FUNC_CTL Apparently ICL may hang with an MCE if we write TRANS_VRR_VMAX/FLIPLINE before enabling TRANS_DDI_FUNC_CTL. Personally I was only able to reproduce a hang (on an Dell XPS 7390 2-in-1) with an external display connected via a dock using a dodgy type-C cable that

  2. Jun 26, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: drm/i915/vrr: Configure VRR timings after enabling TRANS_DDI_FUNC_CTL Apparently ICL may hang with an MCE if we write TRANS_VRR_VMAX/FLIPLINE before enabling TRANS_DDI_FUNC_CTL. Personally I was only able to reproduce a hang (on an Dell XPS 7390 2-in-1) with an external display connected via a dock using a dodgy type-C cable that

Affected

  • cpe linux/linux kernelversion unspecified
  • cpe linux/linux kernel7.0

Sources

  • CVE.orgVulnerability recordCVE-2026-43477

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-43477

    In the Linux kernel, the following vulnerability has been resolved: drm/i915/vrr: Configure VRR timings after enabling TRANS_DDI_FUNC_CTL Apparently ICL may hang with an MCE if we write TRANS_VRR_VMAX/FLIPLINE before enabling TRANS_DDI_FUNC_CTL. Personally I was only able to r

    nvd.nist.gov

References