{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63844","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T07:54:57.015Z","datePublished":"2026-07-19T14:04:38.452Z","dateUpdated":"2026-08-05T12:36:21.992Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:36:21.992Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/jpeg: set no_user_fence for JPEG v4.0.3 ring\n\nJPEG rings do not support 64-bit user fence writes, reject CS\nsubmissions with user fences.\n\n(cherry picked from commit 2f6afc97d259d530f4f86c7743efbc573a8da927)"}],"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 - Exploitation requires local access to the AMDGPU DRM render node and the DRM_IOCTL_AMDGPU_CS ioctl path; there is no network, adjacent-wireless, or physical-access entry point to the vulnerable JPEG ring submission code.\nAC:L - An attacker with render-node access can deterministically submit a command stream to the VCN JPEG ring with an AMDGPU_CHUNK_ID_FENCE user-fence chunk; no race or attacker-uncontrollable memory layout is required beyond having affected VCN 4.0.3 hardware.\nPR:L - The vulnerable amdgpu_cs_ioctl handler is gated by DRM_AUTH|DRM_RENDER_ALLOW, requiring a local unprivileged user with access to /dev/dri/renderD* (typically the render/video group), not root or capabilities obtainable only in the init namespace.\nUI:N - Once the attacker has render-node access, triggering the bug is fully programmatic via ioctl/GEM setup and does not require any additional victim interaction such as opening files or mounting filesystems.\nS:U - Impact is confined to the AMDGPU driver/GPU memory domain of the submitting process's security context; this is not a KVM guest-to-host escape, IOMMU bypass, or other cross-authority boundary crossing.\nC:H - Incorrect 64-bit user-fence handling on JPEG hardware can cause GPU-initiated writes to unintended addresses in GPU-visible memory, a memory-corruption primitive that can be leveraged for arbitrary kernel/GPU memory disclosure beyond the intended fence buffer.\nI:H - The bug allows the GPU to perform unintended memory writes when processing user-fence completion on a ring that lacks 64-bit user-fence support, providing a writable corruption primitive that could be developed into further code execution or privilege escalation.\nA:H - Submitting unsupported user fences to the JPEG v4.0.3 ring can hang or reset the GPU/firmware and trigger repeated denial of service on affected AMD systems (workstations, laptops, cloud GPU instances) using VCN 4.0.3."}]}],"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/jpeg_v4_0_3.c"],"versions":[{"version":"e684e654eba9481a9f462a7bbf5c385b7d1c076e","lessThan":"b884ff67d62ef514eee9d5f605c03101c8b6bc98","status":"affected","versionType":"git"},{"version":"e684e654eba9481a9f462a7bbf5c385b7d1c076e","lessThan":"d6bd2a5fd611ec9c8a2411f084cff2435c709608","status":"affected","versionType":"git"},{"version":"e684e654eba9481a9f462a7bbf5c385b7d1c076e","lessThan":"8549b3933038e68dc61cb934b9a54223dd244a78","status":"affected","versionType":"git"},{"version":"e684e654eba9481a9f462a7bbf5c385b7d1c076e","lessThan":"249fa7549736de1c8e327d7ca6b32fa148a40bd6","status":"affected","versionType":"git"},{"version":"e684e654eba9481a9f462a7bbf5c385b7d1c076e","lessThan":"83e37c0987ca92f9e87789b46dd311dcf5a4a6c8","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/amdgpu/jpeg_v4_0_3.c"],"versions":[{"version":"6.5","status":"affected"},{"version":"0","lessThan":"6.5","status":"unaffected","versionType":"semver"},{"version":"6.6.141","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.91","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"6.5","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/b884ff67d62ef514eee9d5f605c03101c8b6bc98"},{"url":"https://git.kernel.org/stable/c/d6bd2a5fd611ec9c8a2411f084cff2435c709608"},{"url":"https://git.kernel.org/stable/c/8549b3933038e68dc61cb934b9a54223dd244a78"},{"url":"https://git.kernel.org/stable/c/249fa7549736de1c8e327d7ca6b32fa148a40bd6"},{"url":"https://git.kernel.org/stable/c/83e37c0987ca92f9e87789b46dd311dcf5a4a6c8"}],"title":"drm/amdgpu/jpeg: set no_user_fence for JPEG v4.0.3 ring","x_generator":{"engine":"bippy-1.2.0"}}}}