{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68107", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.368Z", "datePublished": "2026-08-10T11:58:24.135Z", "dateUpdated": "2026-10-19T20:58:50.974Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:58:56.350Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn4: avoid rereading IB param length\n\nReuse the parameter length returned by\nvcn_v4_0_enc_find_ib_param() instead of rereading it from\nthe IB.\n\nThis avoids a potential TOCTOU issue if the IB contents\nchange between reads.\n\n(cherry picked from commit dbb02b4755f8c1f3773263f2d779872c1c0c073a)" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is only reachable through the local AMDGPU_CS DRM ioctl on /dev/dri/renderD* (amdgpu_cs_ioctl → amdgpu_cs_patch_jobs → amdgpu_cs_patch_ibs), which kmaps the user IB and calls vcn_v4_0_ring_patch_cs_in_place(); no network or physical-device path exists.\nAC:L - patch_cs_in_place reads IB contents directly from attacker-mapped GEM memory without copying; a concurrent thread can change the param-length dword between vcn_v4_0_enc_find_ib_param()'s initial read and the later idx+=amdgpu_ib_get_value(ib,idx)/4, so the attacker controls both sides of the TOCTOU race.\nPR:L - AMDGPU_CS is registered with DRM_AUTH|DRM_RENDER_ALLOW, so any local user who can open the AMDGPU render node (typical render/video group on desktops, gaming handhelds, and GPU cloud instances) can submit VCN4 command buffers without root or init-namespace capabilities.\nUI:N - Exploitation requires only the attacker submitting crafted VCN encode IBs through their own DRM context; no separate victim action such as opening a file, mounting a filesystem, or interacting with malicious content is needed.\nS:C - On VFIO GPU-passthrough and cloud ML hosts, a malicious VM guest submits VCN command streams through the assigned AMD GPU to corrupt host amdgpu kernel state, crossing the guest-to-hypervisor security boundary analogous to a device-model escape.\nC:H - Racing the length dword smaller under-advances IB iteration so nested RADEON_VCN_ENGINE_INFO entries inside a parent package are reached; vcn_v4_0_dec_msg() then reads user-mapped message buffers without snapshotting, enabling TOCTOU check/use mismatches on length/offset fields and out-of-bounds kernel reads past validated bounds.\nI:H - The same nested-entry bypass plus unsnapshotted dec_msg parsing lets userspace rewrite offset/size after kernel validation, driving out-of-bounds accesses in the message loop; skipping vcn_v4_0_limit_sched() via mis-iteration also leaves scheduler/BO state inconsistently modified in attacker-influenceable ways.\nA:H - Racing the length field to zero on re-read makes idx+=0 and re-enters the same ENGINE_INFO entry indefinitely, soft-locking the CS ioctl path; vcn_v4_0_limit_sched() may also block in dma_fence_wait(), yielding repeatable kernel denial-of-service on shared GPU hosts." } ] } ], "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/amdgpu/vcn_v4_0.c" ], "versions": [ { "version": "cfdde9197ecd957281507be99af172671a57755c", "lessThan": "bbbe6a2a8d8dc87243438d3ffea2083b52d882d9", "status": "affected", "versionType": "git" }, { "version": "6dc4eddeb7e6cca7e1ab32cafbda79d06e652d84", "lessThan": "ff6aa542d91d76a185f69bd1997b94a560ff5f6b", "status": "affected", "versionType": "git" }, { "version": "2b10cb58d7a3fd621ec9b2ba765a092e562ef998", "lessThan": "bd868c077f67589ed2a714307ceaade5f246e302", "status": "affected", "versionType": "git" }, { "version": "2b10cb58d7a3fd621ec9b2ba765a092e562ef998", "lessThan": "c309626bf91fa0a0b583575654e6e14e81f818a3", "status": "affected", "versionType": "git" }, { "version": "2b10cb58d7a3fd621ec9b2ba765a092e562ef998", "lessThan": "3b4082fabc67c9780b06eb959e59dd92fa79c0f0", "status": "affected", "versionType": "git" }, { "version": "b1dc92f55b22a80ded8f0263c9ef4ba902303895", "status": "affected", "versionType": "git" }, { "version": "6.6.107", "lessThan": "6.6.148", "status": "affected", "versionType": "semver" }, { "version": "6.12.48", "lessThan": "6.12.101", "status": "affected", "versionType": "semver" }, { "version": "6.16.8", "lessThan": "6.17", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c" ], "versions": [ { "version": "6.17", "status": "affected" }, { "version": "0", "lessThan": "6.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.6.107", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.48", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bbbe6a2a8d8dc87243438d3ffea2083b52d882d9" }, { "url": "https://git.kernel.org/stable/c/ff6aa542d91d76a185f69bd1997b94a560ff5f6b" }, { "url": "https://git.kernel.org/stable/c/bd868c077f67589ed2a714307ceaade5f246e302" }, { "url": "https://git.kernel.org/stable/c/c309626bf91fa0a0b583575654e6e14e81f818a3" }, { "url": "https://git.kernel.org/stable/c/3b4082fabc67c9780b06eb959e59dd92fa79c0f0" } ], "title": "drm/amdgpu/vcn4: avoid rereading IB param length", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-68107", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T15:43:57.531323Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-367", "description": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:58:50.974Z" } } ] } }