CVE-2026-46263 (GCVE-0-2026-46263)
Vulnerability from cvelistv5
Published
2026-06-03 15:50
Modified
2026-08-05 12:30
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix out-of-bounds stream encoder index v3 eng_id can be negative and that stream_enc_regs[] can be indexed out of bounds. eng_id is used directly as an index into stream_enc_regs[], which has only 5 entries. When eng_id is 5 (ENGINE_ID_DIGF) or negative, this can access memory past the end of the array. Add a bounds check using ARRAY_SIZE() before using eng_id as an index. The unsigned cast also rejects negative values. This avoids out-of-bounds access. Fixes the below smatch error: dcn*_resource.c: stream_encoder_create() may index stream_enc_regs[eng_id] out of bounds (size 5). drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn351/dcn351_resource.c 1246 static struct stream_encoder *dcn35_stream_encoder_create( 1247 enum engine_id eng_id, 1248 struct dc_context *ctx) 1249 { ... 1255 1256 /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */ 1257 if (eng_id <= ENGINE_ID_DIGF) { ENGINE_ID_DIGF is 5. should <= be <? Unrelated but, ugh, why is Smatch saying that "eng_id" can be negative? end_id is type signed long, but there are checks in the caller which prevent it from being negative. 1258 vpg_inst = eng_id; 1259 afmt_inst = eng_id; 1260 } else 1261 return NULL; 1262 ... 1281 1282 dcn35_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios, 1283 eng_id, vpg, afmt, --> 1284 &stream_enc_regs[eng_id], ^^^^^^^^^^^^^^^^^^^^^^^ This stream_enc_regs[] array has 5 elements so we are one element beyond the end of the array. ... 1287 return &enc1->base; 1288 } v2: use explicit bounds check as suggested by Roman/Dan; avoid unsigned int cast v3: The compiler already knows how to compare the two values, so the cast (int) is not needed. (Roman)
References
Impacted products
Vendor Product Version
Linux Linux Version: 2728e9c7c84235d2d7bc1403174d071ffc82d6d2
Version: 2728e9c7c84235d2d7bc1403174d071ffc82d6d2
Version: 2728e9c7c84235d2d7bc1403174d071ffc82d6d2
Version: 2728e9c7c84235d2d7bc1403174d071ffc82d6d2
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "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"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "29f3824b08a98d41ecbbfd33580630d7607f962e",
              "status": "affected",
              "version": "2728e9c7c84235d2d7bc1403174d071ffc82d6d2",
              "versionType": "git"
            },
            {
              "lessThan": "263e28add4f4472cfa95150d218955d1945aa413",
              "status": "affected",
              "version": "2728e9c7c84235d2d7bc1403174d071ffc82d6d2",
              "versionType": "git"
            },
            {
              "lessThan": "ca3808d560ad946ab6d089fd1f5bee04b952ead4",
              "status": "affected",
              "version": "2728e9c7c84235d2d7bc1403174d071ffc82d6d2",
              "versionType": "git"
            },
            {
              "lessThan": "abde491143e4e12eecc41337910aace4e8d59603",
              "status": "affected",
              "version": "2728e9c7c84235d2d7bc1403174d071ffc82d6d2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "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"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.75",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.75",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.14",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.4",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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 \u003c= ENGINE_ID_DIGF) {\n\nENGINE_ID_DIGF is 5.  should \u003c= be \u003c?\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-\u003edc_bios,\n    1283                                         eng_id, vpg, afmt,\n--\u003e 1284                                         \u0026stream_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 \u0026enc1-\u003ebase;\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)"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "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": {
        "dateUpdated": "2026-08-05T12:30:50.295Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "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"
        }
      ],
      "title": "drm/amd/display: Fix out-of-bounds stream encoder index v3",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46263",
    "datePublished": "2026-06-03T15:50:02.572Z",
    "dateReserved": "2026-05-13T15:03:33.108Z",
    "dateUpdated": "2026-08-05T12:30:50.295Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.