{"id":"CVE-2026-98786","state":"PUBLISHED","title":"drm/amd/display: guard dc_sink dereferences in MST mode validation","description":"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-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)","publishedAt":"2026-10-18T15:48:22.989Z","updatedAt":"2026-10-19T09:25:39.296Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f04d275d94e164d24516c32437c988a323018f63","status":"affected","lessThan":"daa0437fe5e451856aaf8fda602a9fc2105bbd54","versionType":"git"},{"version":"f04d275d94e164d24516c32437c988a323018f63","status":"affected","lessThan":"217f64f348c90cba62164e7ff38e0ccf78a5ca09","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c"]}],"references":["https://git.kernel.org/stable/c/daa0437fe5e451856aaf8fda602a9fc2105bbd54","https://git.kernel.org/stable/c/217f64f348c90cba62164e7ff38e0ccf78a5ca09"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98786.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98786","state":"PUBLISHED","datePublished":"2026-10-18T15:48:22.989Z","dateUpdated":"2026-10-19T09:25:39.296Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.370Z"},"containers":{"cna":{"title":"drm/amd/display: guard dc_sink dereferences in MST mode validation","descriptions":[{"lang":"en","value":"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-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)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f04d275d94e164d24516c32437c988a323018f63","status":"affected","lessThan":"daa0437fe5e451856aaf8fda602a9fc2105bbd54","versionType":"git"},{"version":"f04d275d94e164d24516c32437c988a323018f63","status":"affected","lessThan":"217f64f348c90cba62164e7ff38e0ccf78a5ca09","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/daa0437fe5e451856aaf8fda602a9fc2105bbd54"},{"url":"https://git.kernel.org/stable/c/217f64f348c90cba62164e7ff38e0ccf78a5ca09"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:25:39.296Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}