{"id":"CVE-2026-46263","state":"PUBLISHED","title":"drm/amd/display: Fix out-of-bounds stream encoder index v3","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Fix out-of-bounds stream encoder index v3\n\neng_id can be negative and that stream_enc_regs[]\ncan be indexed out of bounds.\n\neng_id is used directly as an index into stream_enc_regs[], which has\nonly 5 entries. When eng_id is 5 (ENGINE_ID_DIGF) or negative, this can\naccess memory past the end of the array.\n\nAdd a bounds check using ARRAY_SIZE() before using eng_id as an index.\nThe unsigned cast also rejects negative values.\n\nThis avoids out-of-bounds access.\n\nFixes the below smatch error:\ndcn*_resource.c: stream_encoder_create() may index\nstream_enc_regs[eng_id] out of bounds (size 5).\n\ndrivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn351/dcn351_resource.c\n    1246 static struct stream_encoder *dcn35_stream_encoder_create(\n    1247         enum engine_id eng_id,\n    1248         struct dc_context *ctx)\n    1249 {\n\n    ...\n\n    1255\n    1256         /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */\n    1257         if (eng_id <= ENGINE_ID_DIGF) {\n\nENGINE_ID_DIGF is 5.  should <= be <?\n\nUnrelated but, ugh, why is Smatch saying that \"eng_id\" can be negative?\nend_id is type signed long, but there are checks in the caller which prevent it from being negative.\n\n    1258                 vpg_inst = eng_id;\n    1259                 afmt_inst = eng_id;\n    1260         } else\n    1261                 return NULL;\n    1262\n\n    ...\n\n    1281\n    1282         dcn35_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios,\n    1283                                         eng_id, vpg, afmt,\n--> 1284                                         &stream_enc_regs[eng_id],\n                                                  ^^^^^^^^^^^^^^^^^^^^^^^ This stream_enc_regs[] array has 5 elements so we are one element beyond the end of the array.\n\n    ...\n\n    1287         return &enc1->base;\n    1288 }\n\nv2: use explicit bounds check as suggested by Roman/Dan; avoid unsigned int cast\n\nv3: The compiler already knows how to compare the two values, so the\n    cast (int) is not needed. (Roman)","publishedAt":"2026-06-03T15:50:02.572Z","updatedAt":"2026-10-19T19:36:56.301Z","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":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"29f3824b08a98d41ecbbfd33580630d7607f962e","versionType":"git"},{"version":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"263e28add4f4472cfa95150d218955d1945aa413","versionType":"git"},{"version":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"ca3808d560ad946ab6d089fd1f5bee04b952ead4","versionType":"git"},{"version":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"abde491143e4e12eecc41337910aace4e8d59603","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/resource/dcn315/dcn315_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn316/dcn316_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn321/dcn321_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","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/resource/dcn315/dcn315_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn316/dcn316_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn321/dcn321_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c"]}],"references":["https://git.kernel.org/stable/c/29f3824b08a98d41ecbbfd33580630d7607f962e","https://git.kernel.org/stable/c/263e28add4f4472cfa95150d218955d1945aa413","https://git.kernel.org/stable/c/ca3808d560ad946ab6d089fd1f5bee04b952ead4","https://git.kernel.org/stable/c/abde491143e4e12eecc41337910aace4e8d59603"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46263.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46263","state":"PUBLISHED","datePublished":"2026-06-03T15:50:02.572Z","dateUpdated":"2026-10-19T19:36:56.301Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.108Z"},"containers":{"cna":{"title":"drm/amd/display: Fix out-of-bounds stream encoder index v3","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Fix out-of-bounds stream encoder index v3\n\neng_id can be negative and that stream_enc_regs[]\ncan be indexed out of bounds.\n\neng_id is used directly as an index into stream_enc_regs[], which has\nonly 5 entries. When eng_id is 5 (ENGINE_ID_DIGF) or negative, this can\naccess memory past the end of the array.\n\nAdd a bounds check using ARRAY_SIZE() before using eng_id as an index.\nThe unsigned cast also rejects negative values.\n\nThis avoids out-of-bounds access.\n\nFixes the below smatch error:\ndcn*_resource.c: stream_encoder_create() may index\nstream_enc_regs[eng_id] out of bounds (size 5).\n\ndrivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn351/dcn351_resource.c\n    1246 static struct stream_encoder *dcn35_stream_encoder_create(\n    1247         enum engine_id eng_id,\n    1248         struct dc_context *ctx)\n    1249 {\n\n    ...\n\n    1255\n    1256         /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */\n    1257         if (eng_id <= ENGINE_ID_DIGF) {\n\nENGINE_ID_DIGF is 5.  should <= be <?\n\nUnrelated but, ugh, why is Smatch saying that \"eng_id\" can be negative?\nend_id is type signed long, but there are checks in the caller which prevent it from being negative.\n\n    1258                 vpg_inst = eng_id;\n    1259                 afmt_inst = eng_id;\n    1260         } else\n    1261                 return NULL;\n    1262\n\n    ...\n\n    1281\n    1282         dcn35_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios,\n    1283                                         eng_id, vpg, afmt,\n--> 1284                                         &stream_enc_regs[eng_id],\n                                                  ^^^^^^^^^^^^^^^^^^^^^^^ This stream_enc_regs[] array has 5 elements so we are one element beyond the end of the array.\n\n    ...\n\n    1287         return &enc1->base;\n    1288 }\n\nv2: use explicit bounds check as suggested by Roman/Dan; avoid unsigned int cast\n\nv3: The compiler already knows how to compare the two values, so the\n    cast (int) is not needed. (Roman)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"29f3824b08a98d41ecbbfd33580630d7607f962e","versionType":"git"},{"version":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"263e28add4f4472cfa95150d218955d1945aa413","versionType":"git"},{"version":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"ca3808d560ad946ab6d089fd1f5bee04b952ead4","versionType":"git"},{"version":"2728e9c7c84235d2d7bc1403174d071ffc82d6d2","status":"affected","lessThan":"abde491143e4e12eecc41337910aace4e8d59603","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/resource/dcn315/dcn315_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn316/dcn316_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn321/dcn321_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","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/resource/dcn315/dcn315_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn316/dcn316_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn321/dcn321_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c","drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/29f3824b08a98d41ecbbfd33580630d7607f962e"},{"url":"https://git.kernel.org/stable/c/263e28add4f4472cfa95150d218955d1945aa413"},{"url":"https://git.kernel.org/stable/c/ca3808d560ad946ab6d089fd1f5bee04b952ead4"},{"url":"https://git.kernel.org/stable/c/abde491143e4e12eecc41337910aace4e8d59603"}],"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 flaw is in AMDGPU display core initialization (dc_create/resource_construct during GPU probe), reachable only from the local kernel context, not from the network or physical buses.\nAC:L - When an out-of-range eng_id is passed, the out-of-bounds index is deterministic with no race; the off-by-one check reliably allows ENGINE_ID_DIGF (5) past validation.\nPR:L - Exploitation requires local access on a system with a vulnerable AMD DCN3.x GPU driver loaded; typical desktop/cloud-GPU tenants have local DRM access without real root, though module reload generally needs elevated privileges.\nUI:N - No victim interaction is required; the bug fires during driver/display-core initialization, not from opening a file or approving a prompt.\nS:U - Impact stays within kernel/GPU driver context (wrong MMIO register maps, memory corruption); it does not cross a VM/hypervisor or IOMMU security boundary by itself.\nC:H - Out-of-bounds indexing of stream_enc_regs[] reads adjacent kernel memory into encoder register descriptors, which is an unbounded kernel memory disclosure primitive per kernel CVSS guidance.\nI:H - The corrupted register block pointer is used for subsequent GPU MMIO writes through stream-encoder helpers, enabling misdirected hardware register modification and potential control of display hardware state.\nA:H - Invalid register mappings and out-of-bounds kernel reads can cause kernel oops/panic or GPU hang when display paths are exercised, matching kernel guidance for crash-class availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:30:50.295Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.18.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-46263","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:21:27.958639Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:36:56.301Z"}}]}}}