{"id":"CVE-2026-89819","state":"PUBLISHED","title":"drm/amd/display: validate plane degamma LUT size for private color prop","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: validate plane degamma LUT size for private color prop\n\nUnlike the CRTC degamma path, which is guarded by\namdgpu_dm_verify_lut_sizes(), the per-plane degamma LUT size was never\nvalidated before use. __set_dm_plane_degamma() passed the user-supplied\nsize straight into __is_lut_linear() and, for a non-linear LUT, into\n__set_input_tf() -> __drm_lut_to_dc_gamma(), the latter always iterating\nMAX_COLOR_LUT_ENTRIES entries regardless of the actual LUT size.\n\nA malformed AMD_PLANE_DEGAMMA_LUT blob (e.g. a single entry) could thus\ntrigger a divide-by-zero in __is_lut_linear() or an out-of-bounds read in\n__drm_lut_to_dc_gamma(). Reject any plane degamma LUT whose size does not\nmatch MAX_COLOR_LUT_ENTRIES, mirroring the invariant the code already\nasserts a few lines below (and which the CRTC path enforces).\n\nThe AMD_PLANE_DEGAMMA_LUT property is only exposed on builds with\nAMD_PRIVATE_COLOR defined.","publishedAt":"2026-09-16T10:30:51.898Z","updatedAt":"2026-10-19T08:53:13.333Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/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":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"f6f04d8ae5725bcc893bdc62e3467efd97255c5b","versionType":"git"},{"version":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"0b2615b8b54f58bbdf986dffb38cbc35214a5cc5","versionType":"git"},{"version":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"b10cc09b329245c6d95f8fa3e7f068575e3e0e9f","versionType":"git"},{"version":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"e4c3ab59021e7c146a84b6671f0d530972bd58b4","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_color.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","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_color.c"]}],"references":["https://git.kernel.org/stable/c/f6f04d8ae5725bcc893bdc62e3467efd97255c5b","https://git.kernel.org/stable/c/0b2615b8b54f58bbdf986dffb38cbc35214a5cc5","https://git.kernel.org/stable/c/b10cc09b329245c6d95f8fa3e7f068575e3e0e9f","https://git.kernel.org/stable/c/e4c3ab59021e7c146a84b6671f0d530972bd58b4"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89819.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89819","state":"PUBLISHED","datePublished":"2026-09-16T10:30:51.898Z","dateUpdated":"2026-10-19T08:53:13.333Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.768Z"},"containers":{"cna":{"title":"drm/amd/display: validate plane degamma LUT size for private color prop","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: validate plane degamma LUT size for private color prop\n\nUnlike the CRTC degamma path, which is guarded by\namdgpu_dm_verify_lut_sizes(), the per-plane degamma LUT size was never\nvalidated before use. __set_dm_plane_degamma() passed the user-supplied\nsize straight into __is_lut_linear() and, for a non-linear LUT, into\n__set_input_tf() -> __drm_lut_to_dc_gamma(), the latter always iterating\nMAX_COLOR_LUT_ENTRIES entries regardless of the actual LUT size.\n\nA malformed AMD_PLANE_DEGAMMA_LUT blob (e.g. a single entry) could thus\ntrigger a divide-by-zero in __is_lut_linear() or an out-of-bounds read in\n__drm_lut_to_dc_gamma(). Reject any plane degamma LUT whose size does not\nmatch MAX_COLOR_LUT_ENTRIES, mirroring the invariant the code already\nasserts a few lines below (and which the CRTC path enforces).\n\nThe AMD_PLANE_DEGAMMA_LUT property is only exposed on builds with\nAMD_PRIVATE_COLOR defined."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"f6f04d8ae5725bcc893bdc62e3467efd97255c5b","versionType":"git"},{"version":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"0b2615b8b54f58bbdf986dffb38cbc35214a5cc5","versionType":"git"},{"version":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"b10cc09b329245c6d95f8fa3e7f068575e3e0e9f","versionType":"git"},{"version":"980f8710075acaeb226a94cde6dda8ffad30123c","status":"affected","lessThan":"e4c3ab59021e7c146a84b6671f0d530972bd58b4","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_color.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","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_color.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f6f04d8ae5725bcc893bdc62e3467efd97255c5b"},{"url":"https://git.kernel.org/stable/c/0b2615b8b54f58bbdf986dffb38cbc35214a5cc5"},{"url":"https://git.kernel.org/stable/c/b10cc09b329245c6d95f8fa3e7f068575e3e0e9f"},{"url":"https://git.kernel.org/stable/c/e4c3ab59021e7c146a84b6671f0d530972bd58b4"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through local DRM ioctls (DRM_IOCTL_MODE_CREATEPROPBLOB then DRM_IOCTL_MODE_ATOMIC or MODE_OBJ_SETPROPERTY) on /dev/dri/cardN when setting AMD_PLANE_DEGAMMA_LUT, a private plane property on AMDGPU display; no network or remote-peer path exists into amdgpu_dm color management.\nAC:L - The attacker fully controls the LUT blob size and contents and can deterministically trigger a divide-by-zero with a one-entry blob or a large heap over-read with a short non-linear LUT; no race, memory-layout luck, or victim state is required.\nPR:L - DRM_IOCTL_MODE_ATOMIC requires DRM master, which is the normal state of the logged-in graphical-session user (compositor, gamescope, kiosk, Steam Deck, Android) or the first opener of an unclaimed card; no CAP_SYS_ADMIN or real root is needed.\nUI:N - The attacker creates the undersized blob and issues the atomic commit from their own process; no other user must open a file, plug in a display, or take any action.\nS:U - The divide-by-zero and out-of-bounds read occur in kernel context on the same host inside the amdgpu display driver; impact stays within the kernel security authority with no VM, IOMMU, or sandbox boundary crossed.\nC:H - __drm_lut_to_dc_gamma() always walks MAX_COLOR_LUT_ENTRIES (4096) drm_color_lut records regardless of blob length, over-reading about 32KB of adjacent kernel heap from a short LUT blob and copying those values into dc_gamma and the display pipeline.\nI:H - Kernel heap contents from the over-read are stored into dc_gamma entries and applied by apply_lut_1d() into the plane transfer function that is programmed into DPP degamma hardware, corrupting driver and GPU color-management state with unvalidated memory.\nA:H - A one-entry LUT causes a divide-error (#DE) panic in __is_lut_linear(); a short non-linear LUT makes __drm_lut_to_dc_gamma() walk tens of kilobytes past the blob into potentially unmapped heap, oopsing the kernel on the atomic check/commit path."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:53:13.333Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}