{"id":"CVE-2026-63849","state":"PUBLISHED","title":"drm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 enc ring","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 enc ring\n\nVCN encoder and decoder rings do not support 64-bit user fence writes,\nreject CS submissions with user fences.\n\n(cherry picked from commit e16be95a2c3ee712b142cb27d2dca0b461181359)","publishedAt":"2026-07-19T14:04:41.395Z","updatedAt":"2026-10-19T20:07:51.086Z","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":"346492f30ce3581bf5324c4ae417eab8537dc998","status":"affected","lessThan":"081ef0e46c9cdd26c0db0ef721470393d36b6655","versionType":"git"},{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","status":"affected","lessThan":"5a4bffd67e94944ed3db26a959346cfb7fabaecd","versionType":"git"},{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","status":"affected","lessThan":"8f4954722eab88e10c4ea0c0d3b1269c31421d3a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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/amd/amdgpu/vcn_v5_0_1.c"]}],"references":["https://git.kernel.org/stable/c/081ef0e46c9cdd26c0db0ef721470393d36b6655","https://git.kernel.org/stable/c/5a4bffd67e94944ed3db26a959346cfb7fabaecd","https://git.kernel.org/stable/c/8f4954722eab88e10c4ea0c0d3b1269c31421d3a"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63849.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63849","state":"PUBLISHED","datePublished":"2026-07-19T14:04:41.395Z","dateUpdated":"2026-10-19T20:07:51.086Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.016Z"},"containers":{"cna":{"title":"drm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 enc ring","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 enc ring\n\nVCN encoder and decoder rings do not support 64-bit user fence writes,\nreject CS submissions with user fences.\n\n(cherry picked from commit e16be95a2c3ee712b142cb27d2dca0b461181359)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","status":"affected","lessThan":"081ef0e46c9cdd26c0db0ef721470393d36b6655","versionType":"git"},{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","status":"affected","lessThan":"5a4bffd67e94944ed3db26a959346cfb7fabaecd","versionType":"git"},{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","status":"affected","lessThan":"8f4954722eab88e10c4ea0c0d3b1269c31421d3a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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/amd/amdgpu/vcn_v5_0_1.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/081ef0e46c9cdd26c0db0ef721470393d36b6655"},{"url":"https://git.kernel.org/stable/c/5a4bffd67e94944ed3db26a959346cfb7fabaecd"},{"url":"https://git.kernel.org/stable/c/8f4954722eab88e10c4ea0c0d3b1269c31421d3a"}],"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 vulnerability is reached only through local DRM ioctls (primarily DRM_IOCTL_AMDGPU_CS on a /dev/dri/renderD* node), not over any network protocol.\nAC:L - An attacker with render-node access can deterministically submit a VCN_ENC command buffer with an AMDGPU_CHUNK_ID_FENCE chunk; no race or attacker-uncontrollable conditions are required beyond having the affected AMDGPU hardware.\nPR:L - Exploitation requires only local access to the GPU render node as an unprivileged user (DRM_AUTH|DRM_RENDER_ALLOW); no root or special capabilities are needed.\nUI:N - Triggering the bug requires only the attacker's own ioctl submissions; no action by another user or victim is required.\nS:U - Impact is confined to the attacker's GPU command-submission context and process GPU virtual address space; it does not cross a VM/host or other security-boundary scope.\nC:H - The unsupported 64-bit user-fence path causes the VCN engine to perform GPU memory writes to attacker-influenced addresses, which constitutes exploitable memory corruption that can be leveraged for information disclosure.\nI:H - The malformed fence write gives the attacker a GPU-initiated arbitrary memory write primitive within their GPU VA space, which can corrupt adjacent buffers and be chained toward code execution.\nA:H - Submitting unsupported user fences to the VCN ring can hang or reset the GPU and trigger kernel driver errors, causing denial of service on affected systems."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:36:27.366Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-63849","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:32:07.985488Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","type":"CWE","description":"CWE-20 Improper Input Validation"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:07:51.086Z"}}]}}}