{"id":"CVE-2026-68274","state":"PUBLISHED","title":"drm/xe/guc: Fix buffer overflow in steered register list allocation","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe/guc: Fix buffer overflow in steered register list allocation\n\nThe size calculation for the steered register extarray uses only the\ngeometry DSS mask (g_dss_mask) to determine the number of entries to\nallocate:\n\n  total = bitmap_weight(gt->fuse_topo.g_dss_mask, ...) * steer_reg_num;\n\nHowever, the filling loop uses for_each_dss_steering(), which iterates\nover for_each_dss(), defined as the union of g_dss_mask and c_dss_mask\n(geometry + compute DSS). On platforms with compute-only DSS bits, the\nloop writes past the allocated buffer, corrupting adjacent slab objects.\n\nThis manifests as list_del corruption and SLUB redzone overwrites during\ndrm_managed_release on device unbind, since the overflow corrupts the\ndrmres list_head of neighboring allocations.\n\nFix by computing the allocation size using the union of both DSS masks,\nmatching the iteration pattern of for_each_dss_steering().\n\n--\nv2:\n- use bitmap_weighted_or() (Zhanjun)\n\n(cherry picked from commit 0a78a44f4901aa6c9263e66be7fce02282f1109f)","publishedAt":"2026-08-10T12:01:49.762Z","updatedAt":"2026-10-19T20:58:59.226Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b170d696c1e2226713471d810c63b1162335079f","status":"affected","lessThan":"b485bfb45555163bfa5f565d6a3415fcb3035b02","versionType":"git"},{"version":"b170d696c1e2226713471d810c63b1162335079f","status":"affected","lessThan":"a9a020f3c11eba6573b699f9cf9245a51b025ade","versionType":"git"},{"version":"b170d696c1e2226713471d810c63b1162335079f","status":"affected","lessThan":"632ecc90e1ca5d3b6822bb4d08f84a175b6c42c0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/xe/xe_guc_capture.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/xe/xe_guc_capture.c"]}],"references":["https://git.kernel.org/stable/c/b485bfb45555163bfa5f565d6a3415fcb3035b02","https://git.kernel.org/stable/c/a9a020f3c11eba6573b699f9cf9245a51b025ade","https://git.kernel.org/stable/c/632ecc90e1ca5d3b6822bb4d08f84a175b6c42c0"],"weaknesses":["CWE-787"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68274.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68274","state":"PUBLISHED","datePublished":"2026-08-10T12:01:49.762Z","dateUpdated":"2026-10-19T20:58:59.226Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.379Z"},"containers":{"cna":{"title":"drm/xe/guc: Fix buffer overflow in steered register list allocation","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe/guc: Fix buffer overflow in steered register list allocation\n\nThe size calculation for the steered register extarray uses only the\ngeometry DSS mask (g_dss_mask) to determine the number of entries to\nallocate:\n\n  total = bitmap_weight(gt->fuse_topo.g_dss_mask, ...) * steer_reg_num;\n\nHowever, the filling loop uses for_each_dss_steering(), which iterates\nover for_each_dss(), defined as the union of g_dss_mask and c_dss_mask\n(geometry + compute DSS). On platforms with compute-only DSS bits, the\nloop writes past the allocated buffer, corrupting adjacent slab objects.\n\nThis manifests as list_del corruption and SLUB redzone overwrites during\ndrm_managed_release on device unbind, since the overflow corrupts the\ndrmres list_head of neighboring allocations.\n\nFix by computing the allocation size using the union of both DSS masks,\nmatching the iteration pattern of for_each_dss_steering().\n\n--\nv2:\n- use bitmap_weighted_or() (Zhanjun)\n\n(cherry picked from commit 0a78a44f4901aa6c9263e66be7fce02282f1109f)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b170d696c1e2226713471d810c63b1162335079f","status":"affected","lessThan":"b485bfb45555163bfa5f565d6a3415fcb3035b02","versionType":"git"},{"version":"b170d696c1e2226713471d810c63b1162335079f","status":"affected","lessThan":"a9a020f3c11eba6573b699f9cf9245a51b025ade","versionType":"git"},{"version":"b170d696c1e2226713471d810c63b1162335079f","status":"affected","lessThan":"632ecc90e1ca5d3b6822bb4d08f84a175b6c42c0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/xe/xe_guc_capture.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/xe/xe_guc_capture.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b485bfb45555163bfa5f565d6a3415fcb3035b02"},{"url":"https://git.kernel.org/stable/c/a9a020f3c11eba6573b699f9cf9245a51b025ade"},{"url":"https://git.kernel.org/stable/c/632ecc90e1ca5d3b6822bb4d08f84a175b6c42c0"}],"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 flaw is in the drm/xe GPU driver's GuC ADS/capture-list setup, reached only through local kernel device probe/GuC upload on the machine's own hardware; there is no network or remote-peer input anywhere on the path.\nAC:L - On any affected platform (one whose compute DSS mask contains bits outside the geometry DSS mask) the undersized allocation and the for_each_dss_steering() fill loop mismatch is fully deterministic, so the out-of-bounds write occurs reliably on every driver load without needing a race or a lucky memory layout.\nPR:L - The overflow happens in the xe driver's GuC initialization path, so an attacker needs only ordinary local access to a system with the affected Intel GPU present; no capability check or elevated privilege gates the corrupted code path itself.\nUI:N - No victim action is needed; the buffer overflow occurs automatically during xe_guc_ads_populate() at device probe, with no file to open, filesystem to mount, or user gesture involved.\nS:U - The out-of-bounds write corrupts kernel slab objects belonging to the same kernel security authority; there is no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - The overflow overwrites adjacent slab objects including drmres list_head pointers, and such heap metadata corruption can be leveraged to make subsequent list operations dereference attacker-influenceable heap contents, so an information-disclosure primitive cannot be ruled out.\nI:H - This is a heap out-of-bounds write past the end of the drmm_kzalloc'd extarray, overwriting neighboring allocations' contents and list linkage, which is exactly the class of corruption that yields arbitrary-write and control-flow-hijack primitives.\nA:H - The corruption is confirmed to produce list_del corruption and SLUB redzone overwrites, causing kernel oops/panic during drm_managed_release on device unbind and unpredictable slab corruption beforehand."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:02:07.998Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68274","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:46:31.440786Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","lang":"en","type":"CWE","description":"CWE-787 Out-of-bounds Write"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:58:59.226Z"}}]}}}