{"id":"CVE-2026-98786","title":"drm/amd/display: guard dc_sink dereferences in MST mode validation","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: guard dc_sink dereferences in MST mode validation\n\ndm_dp_mst_is_port_support_mode() reads\naconnector->dc_sink->dsc_caps... for the DSC branch-throughpu…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= f04d275d94e164d24516c32437c988a323018f63 < daa0437fe5e451856aaf8fda602a9fc2105bbd54","Linux >= f04d275d94e164d24516c32437c988a323018f63 < 217f64f348c90cba62164e7ff38e0ccf78a5ca09","Linux 6.0"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:48:22.989Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98786","references":[{"url":"https://git.kernel.org/stable/c/daa0437fe5e451856aaf8fda602a9fc2105bbd54"},{"url":"https://git.kernel.org/stable/c/217f64f348c90cba62164e7ff38e0ccf78a5ca09"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.487Z","slug":"CVE-2026-98786","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: guard dc_sink dereferences in MST mode validation\n\ndm_dp_mst_is_port_support_mode() reads\naconnector->dc_sink->dsc_caps... for the DSC branch-throughput check,\nand get_conv_frl_bw()'s HDMI-PCON FRL-bandwidth path reads\naconnector->dc_sink->edid_caps.max_frl_rate, both without a NULL\ncheck. dc_sink is cleared asynchronously on MST unplug, and both\nfunctions run from paths that the driver's own comments document as\nracing that teardown: the connector probe worker's ->mode_valid\ncallback and a compositor's atomic check, neither of which holds the\nMST manager lock that the teardown path uses. The former does have an\nexisting dsc_aux NULL check, but dsc_aux isn't reliably cleared in\nevery path that clears dc_sink, so it doesn't cover this.\n\nFail the port-support check and skip the FRL conversion path when the\nsink is already gone.\n\n(cherry picked from commit 7c3db8da4e039698ae198c870712428644e965c7)\n\n## Affected\n\n- `Linux >= f04d275d94e164d24516c32437c988a323018f63 < daa0437fe5e451856aaf8fda602a9fc2105bbd54`\n- `Linux >= f04d275d94e164d24516c32437c988a323018f63 < 217f64f348c90cba62164e7ff38e0ccf78a5ca09`\n- `Linux 6.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}