{"id":"CVE-2026-64219","state":"PUBLISHED","title":"drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async\n\n[Why&How]\ndc_process_dmub_aux_transfer_async() copies payload->length bytes into a\n16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which\nis a no-op in release builds. If a caller ever passes length > 16 this\nresults in a stack buffer overflow via memcpy.\n\nAdditionally, link_index is used to dereference dc->links[] without\nbounds checking against dc->link_count, risking an out-of-bounds access.\n\nReplace the ASSERT with a hard runtime check that returns false when\npayload->length exceeds the destination buffer size, and add a bounds\ncheck for link_index before it is used.\n\n(cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881)","publishedAt":"2026-07-24T15:23:06.379Z","updatedAt":"2026-10-19T20:28:15.578Z","severity":{"score":7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"d6590e3f766e3111dd1beaf88b9384d117acfa6b","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"16a5fa57565afb6bf37e18129921c270c93d8e2b","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"90c398e822ca76e40548df0c061dd4f93ea92d71","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"3265f3ed373fb8048be713aadcdf702579a0e53d","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"1ecde19bfce6535bffddad1139ff466b6d401b8e","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"1c8c6e912f2945b2a3e669afca6b52174b88e86e","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"6c92f6d9600efa3ef0d9e560a2b52776d9803c29","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/core/dc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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/dc/core/dc.c"]}],"references":["https://git.kernel.org/stable/c/d6590e3f766e3111dd1beaf88b9384d117acfa6b","https://git.kernel.org/stable/c/16a5fa57565afb6bf37e18129921c270c93d8e2b","https://git.kernel.org/stable/c/90c398e822ca76e40548df0c061dd4f93ea92d71","https://git.kernel.org/stable/c/3265f3ed373fb8048be713aadcdf702579a0e53d","https://git.kernel.org/stable/c/1ecde19bfce6535bffddad1139ff466b6d401b8e","https://git.kernel.org/stable/c/1c8c6e912f2945b2a3e669afca6b52174b88e86e","https://git.kernel.org/stable/c/6c92f6d9600efa3ef0d9e560a2b52776d9803c29"],"weaknesses":["CWE-121"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64219.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64219","state":"PUBLISHED","datePublished":"2026-07-24T15:23:06.379Z","dateUpdated":"2026-10-19T20:28:15.578Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.770Z"},"containers":{"cna":{"title":"drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async\n\n[Why&How]\ndc_process_dmub_aux_transfer_async() copies payload->length bytes into a\n16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which\nis a no-op in release builds. If a caller ever passes length > 16 this\nresults in a stack buffer overflow via memcpy.\n\nAdditionally, link_index is used to dereference dc->links[] without\nbounds checking against dc->link_count, risking an out-of-bounds access.\n\nReplace the ASSERT with a hard runtime check that returns false when\npayload->length exceeds the destination buffer size, and add a bounds\ncheck for link_index before it is used.\n\n(cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"d6590e3f766e3111dd1beaf88b9384d117acfa6b","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"16a5fa57565afb6bf37e18129921c270c93d8e2b","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"90c398e822ca76e40548df0c061dd4f93ea92d71","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"3265f3ed373fb8048be713aadcdf702579a0e53d","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"1ecde19bfce6535bffddad1139ff466b6d401b8e","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"1c8c6e912f2945b2a3e669afca6b52174b88e86e","versionType":"git"},{"version":"4f8e37dbaf584de6d38f58b3000b0bfd7eaf2ff6","status":"affected","lessThan":"6c92f6d9600efa3ef0d9e560a2b52776d9803c29","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/core/dc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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/dc/core/dc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/d6590e3f766e3111dd1beaf88b9384d117acfa6b"},{"url":"https://git.kernel.org/stable/c/16a5fa57565afb6bf37e18129921c270c93d8e2b"},{"url":"https://git.kernel.org/stable/c/90c398e822ca76e40548df0c061dd4f93ea92d71"},{"url":"https://git.kernel.org/stable/c/3265f3ed373fb8048be713aadcdf702579a0e53d"},{"url":"https://git.kernel.org/stable/c/1ecde19bfce6535bffddad1139ff466b6d401b8e"},{"url":"https://git.kernel.org/stable/c/1c8c6e912f2945b2a3e669afca6b52174b88e86e"},{"url":"https://git.kernel.org/stable/c/6c92f6d9600efa3ef0d9e560a2b52776d9803c29"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The closest attack surface is the local DRM DisplayPort AUX character-device path; no network protocol reaches this function. Physical USB4/DisplayPort devices can initiate AUX activity but cannot directly supply the vulnerable length or index.\nAC:H - All current callers cap transactions at 16 bytes, while link_index is derived from an internally created dc_link. Exploitation therefore requires an abnormal internal caller or corrupted state that the attacker cannot directly create.\nPR:L - Reaching the relevant DRM/AUX interfaces requires local device access, but the traced path contains no administrative capability or init-namespace privilege check. Basic session or device-ACL access is therefore sufficient.\nUI:N - Once the attacker has local device access and the required abnormal state exists, the vulnerable copy or dereference executes without further victim action.\nS:U - The corruption occurs within the host kernel and does not inherently cross a separate virtualization, IOMMU, or other security authority boundary.\nC:H - A length greater than 40 can copy payload-controlled bytes beyond the 64-byte stack command and overwrite control data. Successful control-flow hijacking would permit arbitrary kernel-memory disclosure.\nI:H - The unbounded stack write can overwrite saved state and potentially enable kernel code execution; an invalid link_index can also dereference a wild pointer. This supports complete integrity impact.\nA:H - FORTIFY converts a sufficiently large copy into a kernel panic, while unfortified stack corruption, stack-canary failure, or the unchecked link dereference can cause an oops or crash."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:40:07.374Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64219","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:37:34.646600Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-121","lang":"en","type":"CWE","description":"CWE-121 Stack-based Buffer Overflow"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:28:15.578Z"}}]}}}