{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-21985","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-12-29T08:45:45.799Z","datePublished":"2025-04-01T15:47:12.103Z","dateUpdated":"2026-08-05T11:55:51.832Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:55:51.832Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Fix out-of-bound accesses\n\n[WHAT & HOW]\nhpo_stream_to_link_encoder_mapping has size MAX_HPO_DP2_ENCODERS(=4),\nbut location can have size up to 6. As a result, it is necessary to\ncheck location against MAX_HPO_DP2_ENCODERS.\n\nSimiliarly, disp_cfg_stream_location can be used as an array index which\nshould be 0..5, so the ASSERT's conditions should be less without equal."}],"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 vulnerable code is reached only through the local DRM atomic modeset ioctl (`DRM_IOCTL_MODE_ATOMIC`) on /dev/dri/card*, via amdgpu_dm_atomic_check() → dc_validate_global_state() → dml2_validate(); no network or remote peer data is involved.\nAC:L - Once a DisplayPort configuration with five or more streams/planes exists (multi-monitor or MST/dock setups, SubVP phantom streams, or primaries plus an MPO overlay), the out-of-bounds index is hit deterministically on every validation pass, and the attacker can re-issue TEST_ONLY atomic commits repeatedly with plane/stream assignments of their choosing.\nPR:L - The atomic ioctl is registered with DRM_MASTER only, which an ordinary unprivileged user holds for their active graphical session on the amdgpu card node — no root, no capability, and no init-namespace privilege is required.\nUI:N - The attacker performs the atomic commit themselves from their own session; no action by any other user is needed to trigger the out-of-bounds access.\nS:U - The corruption is confined to kernel heap memory belonging to the amdgpu display driver within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The read at hpo_stream_to_link_encoder_mapping[4..5] pulls kernel data from beyond the array into adjacent struct state (g6_temp_read_watermark_set), and the resulting out-of-bounds heap write is a corruption primitive that can be leveraged to shape adjacent kernel objects for disclosure.\nI:H - The out-of-bounds value is used directly as an index into the 8-entry OutputEncoder[] array, producing a 4-byte write at a large, configuration-influenced offset that lands outside the kzalloc'd struct dml2_context, corrupting neighbouring heap objects as well as the DML output configuration that drives display hardware programming.\nA:H - The wild write corrupts kernel heap memory and the display-config state used for bandwidth/watermark programming, leading to oops, slab corruption, or hung/underflowing display output requiring recovery."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c","drivers/gpu/drm/amd/display/dc/dml2/dml2_translation_helper.c"],"versions":[{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"36793d90d76f667d26c6dd025571481ee0c96abc","status":"affected","versionType":"git"},{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"9aedc776b11038f04f4641241bb7e877781e4aa4","status":"affected","versionType":"git"},{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"8adbb2a98b00926315fd513b5fe2596b5716b82d","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c","drivers/gpu/drm/amd/display/dc/dml2/dml2_translation_helper.c"],"versions":[{"version":"4.15","status":"affected"},{"version":"0","lessThan":"4.15","status":"unaffected","versionType":"semver"},{"version":"6.12.20","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.13.8","lessThanOrEqual":"6.13.*","status":"unaffected","versionType":"semver"},{"version":"6.14","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.12.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.13.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.14"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/36793d90d76f667d26c6dd025571481ee0c96abc"},{"url":"https://git.kernel.org/stable/c/9aedc776b11038f04f4641241bb7e877781e4aa4"},{"url":"https://git.kernel.org/stable/c/8adbb2a98b00926315fd513b5fe2596b5716b82d"}],"title":"drm/amd/display: Fix out-of-bound accesses","x_generator":{"engine":"bippy-1.2.0"}}}}