{"api_version":"1","generated_at":"2026-08-13T12:30:16+00:00","cve":"CVE-2026-68436","urls":{"html":"https://cve.report/CVE-2026-68436","api":"https://cve.report/api/cve/CVE-2026-68436.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-68436","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-68436"},"summary":{"title":"drm/amd/display: use kvzalloc to allocate struct dc","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: use kvzalloc to allocate struct dc\n\nstruct dc has grown large over time (most of it the two inlined\ndc_scratch_space copies) and now sits close to the page allocator's 4 MiB\ncontiguous allocation limit. Its actual size is not fixed by the source\nalone, it also depends on the compiler and the .config, so it can easily\ncross 4 MiB, e.g. with a newer GCC or a config change.\n\ndc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the\nrequest is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER,\nso the page allocator warns and returns NULL. dc_create() then fails, DM\ninit fails and amdgpu probe aborts with -EINVAL:\n\n  WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380\n   dc_create+0x38/0x660 [amdgpu]\n   amdgpu_dm_init+0x2d9/0x510 [amdgpu]\n   dm_hw_init+0x1b/0x90 [amdgpu]\n   amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu]\n   amdgpu_driver_load_kms+0x19/0x80 [amdgpu]\n   amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu]\n\ndc_create() then returns NULL and DM init fails, which aborts the whole\nGPU init and makes amdgpu probe fail with -EINVAL (\"hw_init of IP block\n<dm> failed -22\"), leaving the display unusable. The subsequent\namdgpu_irq_put() warnings during teardown are just fallout of unwinding\na half-initialized device.\n\nstruct dc is a software-only bookkeeping structure that is never handed\nto hardware DMA and is only ever kept as an opaque pointer, so it does\nnot require physically contiguous memory. Allocate it with kvzalloc()\n(and free it with kvfree()) so that the allocator can fall back to\nvmalloc() when a contiguous allocation of that size is not available,\nwhich also avoids the MAX_PAGE_ORDER warning entirely.\n\nv2:\n - Rebase to amd-staging-drm-next.\n\n(cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-12 00:17:43","updated_at":"2026-08-12 00:17:43"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/75050390151a14802be433c3856ddcb483cecd24","name":"https://git.kernel.org/stable/c/75050390151a14802be433c3856ddcb483cecd24","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dbad70d40cad9c5e7586953275287fe7531fb811","name":"https://git.kernel.org/stable/c/dbad70d40cad9c5e7586953275287fe7531fb811","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68436","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68436","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 dbad70d40cad9c5e7586953275287fe7531fb811 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 75050390151a14802be433c3856ddcb483cecd24 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1.6 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.6 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"68436","cve":"CVE-2026-68436","epss":"0.001450000","percentile":"0.042690000","score_date":"2026-08-12","updated_at":"2026-08-13 00:04:46"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/gpu/drm/amd/display/dc/core/dc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"dbad70d40cad9c5e7586953275287fe7531fb811","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"75050390151a14802be433c3856ddcb483cecd24","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"7.1.6","status":"affected","version":"0","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/gpu/drm/amd/display/dc/core/dc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc2","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: use kvzalloc to allocate struct dc\n\nstruct dc has grown large over time (most of it the two inlined\ndc_scratch_space copies) and now sits close to the page allocator's 4 MiB\ncontiguous allocation limit. Its actual size is not fixed by the source\nalone, it also depends on the compiler and the .config, so it can easily\ncross 4 MiB, e.g. with a newer GCC or a config change.\n\ndc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the\nrequest is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER,\nso the page allocator warns and returns NULL. dc_create() then fails, DM\ninit fails and amdgpu probe aborts with -EINVAL:\n\n  WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380\n   dc_create+0x38/0x660 [amdgpu]\n   amdgpu_dm_init+0x2d9/0x510 [amdgpu]\n   dm_hw_init+0x1b/0x90 [amdgpu]\n   amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu]\n   amdgpu_driver_load_kms+0x19/0x80 [amdgpu]\n   amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu]\n\ndc_create() then returns NULL and DM init fails, which aborts the whole\nGPU init and makes amdgpu probe fail with -EINVAL (\"hw_init of IP block\n<dm> failed -22\"), leaving the display unusable. The subsequent\namdgpu_irq_put() warnings during teardown are just fallout of unwinding\na half-initialized device.\n\nstruct dc is a software-only bookkeeping structure that is never handed\nto hardware DMA and is only ever kept as an opaque pointer, so it does\nnot require physically contiguous memory. Allocate it with kvzalloc()\n(and free it with kvfree()) so that the allocator can fall back to\nvmalloc() when a contiguous allocation of that size is not available,\nwhich also avoids the MAX_PAGE_ORDER warning entirely.\n\nv2:\n - Rebase to amd-staging-drm-next.\n\n(cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)"}],"providerMetadata":{"dateUpdated":"2026-08-12T00:07:24.698Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/dbad70d40cad9c5e7586953275287fe7531fb811"},{"url":"https://git.kernel.org/stable/c/75050390151a14802be433c3856ddcb483cecd24"}],"title":"drm/amd/display: use kvzalloc to allocate struct dc","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-68436","datePublished":"2026-08-12T00:07:24.698Z","dateReserved":"2026-07-30T09:28:09.394Z","dateUpdated":"2026-08-12T00:07:24.698Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-12 00:17:43","lastModifiedDate":"2026-08-12 00:17:43","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"68436","Ordinal":"1","Title":"drm/amd/display: use kvzalloc to allocate struct dc","CVE":"CVE-2026-68436","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"68436","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: use kvzalloc to allocate struct dc\n\nstruct dc has grown large over time (most of it the two inlined\ndc_scratch_space copies) and now sits close to the page allocator's 4 MiB\ncontiguous allocation limit. Its actual size is not fixed by the source\nalone, it also depends on the compiler and the .config, so it can easily\ncross 4 MiB, e.g. with a newer GCC or a config change.\n\ndc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the\nrequest is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER,\nso the page allocator warns and returns NULL. dc_create() then fails, DM\ninit fails and amdgpu probe aborts with -EINVAL:\n\n  WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380\n   dc_create+0x38/0x660 [amdgpu]\n   amdgpu_dm_init+0x2d9/0x510 [amdgpu]\n   dm_hw_init+0x1b/0x90 [amdgpu]\n   amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu]\n   amdgpu_driver_load_kms+0x19/0x80 [amdgpu]\n   amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu]\n\ndc_create() then returns NULL and DM init fails, which aborts the whole\nGPU init and makes amdgpu probe fail with -EINVAL (\"hw_init of IP block\n<dm> failed -22\"), leaving the display unusable. The subsequent\namdgpu_irq_put() warnings during teardown are just fallout of unwinding\na half-initialized device.\n\nstruct dc is a software-only bookkeeping structure that is never handed\nto hardware DMA and is only ever kept as an opaque pointer, so it does\nnot require physically contiguous memory. Allocate it with kvzalloc()\n(and free it with kvfree()) so that the allocator can fall back to\nvmalloc() when a contiguous allocation of that size is not available,\nwhich also avoids the MAX_PAGE_ORDER warning entirely.\n\nv2:\n - Rebase to amd-staging-drm-next.\n\n(cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)","Type":"Description","Title":"drm/amd/display: use kvzalloc to allocate struct dc"}]}}}