{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40354","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T07:20:57.187Z","datePublished":"2025-12-16T13:30:27.082Z","dateUpdated":"2026-08-05T12:09:51.348Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:09:51.348Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: increase max link count and fix link->enc NULL pointer access\n\n[why]\n1.) dc->links[MAX_LINKS] array size smaller than actual requested.\nmax_connector + max_dpia + 4 virtual = 14.\nincrease from 12 to 14.\n\n2.) hw_init() access null LINK_ENC for dpia non display_endpoint.\n\n(cherry picked from commit d7f5a61e1b04ed87b008c8d327649d184dc5bb45)"}],"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 defect is in the amdgpu DC display driver's hardware-init path, reached through local driver probe and suspend/resume (including runtime-PM resume driven by opening /dev/dri/renderD*). There is no network-facing component.\nAC:L - Both the unbounded `dc->links[]` append in create_links() and the NULL `link->link_enc` dereference for DPIA endpoints are deterministic on affected DCN4x configurations — no race to win and no memory layout beyond the attacker's influence.\nPR:L - The vulnerable init_hw path is re-entered on every runtime-PM/system resume via dm_resume() -> dc_set_power_state(D0), which an unprivileged local user holding an ordinary DRM/render node handle can drive repeatedly; no root or CAP_SYS_ADMIN is required.\nUI:N - No victim action is needed — the corrupting create_links() loop runs at driver init and the NULL dereference is hit automatically on each hardware init/resume cycle.\nS:U - The out-of-bounds write and NULL dereference stay within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Overflowing dc->links[] overwrites the adjacent `struct link_service *link_srv`, `current_state`, and `res_pool` pointers in struct dc, so subsequent dc->link_srv->...() dispatches read from an attacker-influenceable heap object, yielding pointer confusion and arbitrary kernel-memory read primitives.\nI:H - This is an out-of-bounds write of pointer values past a fixed array directly onto a function-pointer-table pointer (link_srv), giving a realistic indirect-call hijack and arbitrary write path rather than a bounded corruption.\nA:H - The unfixed DPIA path dereferences a NULL link->link_enc in dcn401_init_hw(), producing a kernel oops on every hardware init/resume, and the adjacent-field corruption reliably panics the machine."}]}],"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/hwss/dcn401/dcn401_hwseq.c","drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h"],"versions":[{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"f28092be4e12b7df9e4f415d25bf0d767bc2d9ed","status":"affected","versionType":"git"},{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"a3fc0d36cfb927f8986b83bf5fba47dbedad3c63","status":"affected","versionType":"git"},{"version":"4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c","lessThan":"bec947cbe9a65783adb475a5fb47980d7b4f4796","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/hwss/dcn401/dcn401_hwseq.c","drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h"],"versions":[{"version":"4.15","status":"affected"},{"version":"0","lessThan":"4.15","status":"unaffected","versionType":"semver"},{"version":"6.12.56","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.17.6","lessThanOrEqual":"6.17.*","status":"unaffected","versionType":"semver"},{"version":"6.18","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":"6.12.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.17.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.18"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/f28092be4e12b7df9e4f415d25bf0d767bc2d9ed"},{"url":"https://git.kernel.org/stable/c/a3fc0d36cfb927f8986b83bf5fba47dbedad3c63"},{"url":"https://git.kernel.org/stable/c/bec947cbe9a65783adb475a5fb47980d7b4f4796"}],"title":"drm/amd/display: increase max link count and fix link->enc NULL pointer access","x_generator":{"engine":"bippy-1.2.0"}}}}