{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38080","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T04:51:23.980Z","datePublished":"2025-06-18T09:33:53.920Z","dateUpdated":"2026-08-05T11:59:19.178Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:59:19.178Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Increase block_sequence array size\n\n[Why]\nIt's possible to generate more than 50 steps in hwss_build_fast_sequence,\nfor example with a 6-pipe asic where all pipes are in one MPC chain. This\noverflows the block_sequence buffer and corrupts block_sequence_steps,\ncausing a crash.\n\n[How]\nExpand block_sequence to 100 items. A naive upper bound on the possible\nnumber of steps for a 6-pipe asic, ignoring the potential for steps to be\nmutually exclusive, is 91 with current code, therefore 100 is sufficient."}],"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 overflow is reached only through the local DRM atomic-commit/page-flip ioctl path on /dev/dri/cardN (amdgpu_dm_atomic_commit_tail → dc_update_planes_and_stream → commit_planes_for_stream_fast → hwss_build_fast_sequence). There is no network or adjacent-network exposure.\nAC:L - There is no bounds check whatsoever in hwss_build_fast_sequence, so an attacker who submits an atomic commit with many planes in one MPC chain and multiple simultaneous update flags (address, gamma, CTM/out_csc, gamut remap, bias/scale) deterministically drives the step count past 50 on the widely-deployed 6-pipe DCN2.0/DCN3.0 ASICs. No race, timing window, or attacker-uncontrollable state is involved.\nPR:L - Only an ordinary local user session is needed — logind grants the seat user rw access to /dev/dri/cardN and DRM master can be acquired on a free VT or by being the compositor, which is all the DRM_MASTER-gated atomic ioctl requires. No root or CAP_SYS_ADMIN is necessary.\nUI:N - The attacker issues the atomic commit itself; no action by another user or victim is required at any point in the path.\nS:U - The corruption is confined to kernel memory belonging to the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The first overflowing write clobbers block_sequence_steps with a kernel pointer, after which hwss_execute_sequence iterates an enormous count, reading out-of-bounds kernel memory as block_sequence entries and dereferencing OOB-derived pointers (mpc, pipe_ctx, csc regval) into display hardware programming — an out-of-bounds read/disclosure primitive, and the in-struct spill over kref refcount enables a dc_state use-after-free that can be leveraged for arbitrary read.\nI:H - This is an unbounded out-of-bounds write: entries 50+ overwrite block_sequence_steps, dc_dmub_cmd[], dmub_cmd_count and the kref refcount, and once the counter holds pointer-derived garbage every further write lands far outside the kvzalloc'd dc_state, giving a wild kernel-heap write usable for control-flow hijacking.\nA:H - The commit message states outright that the overflow corrupts block_sequence_steps and causes a crash; the resulting wild writes and OOB function-pointer dispatch reliably produce a kernel oops/panic."}]}],"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/inc/core_types.h"],"versions":[{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"de67e80ab48f1f23663831007a2fa3c1471a7757","status":"affected","versionType":"git"},{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"e55c5704b12eeea27e212bfab8f7e51ad3e8ac1f","status":"affected","versionType":"git"},{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"bf1666072e7482317cf2302621766482a21a62c7","status":"affected","versionType":"git"},{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"3a7810c212bcf2f722671dadf4b23ff70a7d23ee","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/inc/core_types.h"],"versions":[{"version":"4.15","status":"affected"},{"version":"0","lessThan":"4.15","status":"unaffected","versionType":"semver"},{"version":"6.6.93","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.31","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.14.9","lessThanOrEqual":"6.14.*","status":"unaffected","versionType":"semver"},{"version":"6.15","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":"6.6.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.12.31"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.14.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.15"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/de67e80ab48f1f23663831007a2fa3c1471a7757"},{"url":"https://git.kernel.org/stable/c/e55c5704b12eeea27e212bfab8f7e51ad3e8ac1f"},{"url":"https://git.kernel.org/stable/c/bf1666072e7482317cf2302621766482a21a62c7"},{"url":"https://git.kernel.org/stable/c/3a7810c212bcf2f722671dadf4b23ff70a7d23ee"}],"title":"drm/amd/display: Increase block_sequence array size","x_generator":{"engine":"bippy-1.2.0"}}}}