Local DCHVM hang via non-atomic PHY transition
Published May 6, 2026 · Updated May 6, 2026
Denial of service in the Linux kernel AMD DCN35 display path allows local users to hang DCHVM invalidation handling during TMDS shutdown. The DCN35 PHY state machine disables the PHY PLL without an atomic TX_EN-to-PLL_ON transition, so the OTG remains stuck and DCHVM cannot acknowledge invalidations. Reachability requires an AMD GPU using the DCN35 path and thread preemption before the IOMMU watchdog expires; no data exposure or modification is reported.
Summary
What happened
Denial of service in the Linux kernel AMD DCN35 display path allows local users to hang DCHVM invalidation handling during TMDS shutdown. The DCN35 PHY state machine disables the PHY PLL without an atomic TX_EN-to-PLL_ON transition, so the OTG remains stuck and DCHVM cannot acknowledge invalidations. Reachability requires an AMD GPU using the DCN35 path and thread preemption before the IOMMU watchdog expires; no data exposure or modification is reported.
The record
- CVE
- CVE-2026-43191
- Published
- May 6, 2026
- Updated
- May 6, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 6, 2026CVE publishedPublication date reported by the CVE source.
- May 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <75372d75a4e23783583998ed99d5009d555850da
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d1f7ceb00e8956ff6d183b7b45ef4e73c96f4c51
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