From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80883][MODERATE 7.0] drm/tegra: gr2d/gr3d: Initialize address register map before HOST1X client is registered [ Upstream Date: Fri, 04 Sep 2026 15:47:27 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80883 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 6 X-AL-KERNEL-ActionableScore-Lower: 4 X-AL-KERNEL-Commit: 6e22d5ad61cfa38aa53fab86a530113aff6a3619 List-Id: CVE: CVE-2026-80883 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: drm/tegra: gr2d/gr3d: Initialize address register map before HOST1X client is registered [ Upstream Commit: 6e22d5ad61cfa38aa53fab86a530113aff6a3619 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6e22d5ad61cfa38aa53fab86a530113aff6a3619 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80883 Analysis date: Fri, 04 Sep 2026 15:47:27 -0400 ActionableScore: 6 ActionableScore lower bound: 4 Actionable bucket: Actionable Moderate at minimum Manual review required: YES Summary: A local race in the Tegra DRM gr2d/gr3d probe path can expose the HOST1X client before address register maps are initialized, allowing early userspace job submission while GPU address validation state is incomplete and potentially causing DoS or security-relevant DMA validation bypass. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80883 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80883 The original announcement does not normally provide a security severity estimate, CVSS assessment, or enough information to determine whether the reported kernel bug represents a practically relevant security issue. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. It combines an autonomous classifier with LLM-assisted technical analysis and a separate ActionableScore mechanism. The purpose of this report is to prioritize Linux kernel CVEs before manual review, identify cases that require prompt investigation, and support automatic closure of issues that are unlikely to have meaningful security impact. Published priority for this report: MODERATE 7.0 Manual review required: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-80883 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-80883 CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';CWE-665;CWE-362;CWE-284;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'A race in the Tegra DRM gr2d/gr3d probe path can expose the HOST1X client to userspace before the address register map is initialized. A local process may then submit a GPU job during this small window while address register validation state is incomplete. For the CVSS the PR:L is used because triggering requires local access to the Tegra DRM or host1x userspace interface, not administrator privileges in the paranoid interpretation. The issue is not network reachable and is limited to systems using the affected Tegra DRM engines. Impact is at least local denial of service, and in the worst case may include confidentiality or integrity impact if an early job can program GPU address registers before the normal address validation data is ready.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5) YES OOB DANGER INIT SIMPLEFIX HARDWARE KPANIC KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=6 ActionableScoreLower=4 ## 1. ActionableScore * Conservative score: 4 * Paranoid score: 6 * Final recommended bucket: **Actionable Moderate at minimum**:: ## 2. Signal breakdown Conservative signals: * Local unprivileged trigger: +1. A local process with access to the Tegra DRM or host1x userspace interface may submit a job after HOST1X client registration. * Weak/indirect corruption candidate: +1. The bug exposes job submission while address register validation state is incomplete, but the patch does not demonstrate a direct arbitrary write, UAF, or controlled overwrite primitive. * Privileged kernel/device-management or DMA-adjacent path: +1. The affected state is an address register map used by GPU/host1x job handling, which is security-relevant because GPU jobs may program address-bearing registers. * Integrity impact plausible: +1. If address registers are not recognized or validated correctly during the window, incorrect GPU address programming or validation bypass is plausible. * Availability impact realistic: +1. An early malformed or improperly validated job can plausibly cause GPU faults, job failure, or device instability. * Hard or unreliable race / special timing required: -1. The window exists only between HOST1X client registration and the following address map initialization loop during probe. Paranoid additional signals: * Weak LPE concern: +1. The incomplete address register map is in a DMA-capable GPU submission path, so a manually reviewed worst case should consider whether early job submission can affect memory access policy. * Confidentiality impact plausible: +1. If address register validation is bypassed in the race window, unauthorized GPU reads are a defensible concern, although not demonstrated by the patch. Not applied: * Remote reachable: +0. No network trigger is shown. * Strong generic memory corruption: +0. No UAF, double free, OOB write, heap overwrite, or arbitrary write is shown. * Strong LPE plausibility: +0. There is no demonstrated reclaim, callback control, arbitrary write, or concrete privilege escalation chain. * Broad/default exposure: +0. This is limited to Tegra systems with gr2d/gr3d and accessible DRM/host1x device nodes. ## 3. Reachability analysis The bug is locally reachable on affected Tegra systems if a user can access the DRM/host1x interface and race job submission against driver probe. In typical deployments, access may be limited by device node permissions such as video or render group membership, but it does not inherently require full root if userspace GPU submission is available. Containers do not automatically gain reachability unless the relevant device node is passed through. The path is not network reachable and is hardware-specific to Tegra gr2d/gr3d. Realistic exploitation depends on hitting a narrow initialization window, so the race condition materially reduces reliability. ## 4. Severity interpretation This is stronger than an ordinary low-risk initialization bug because the uninitialized state is an address register map used before exposing a GPU client to userspace. The realistic demonstrated impact is local DoS or device instability from early job submission. The theoretical concern is incomplete validation of address-bearing GPU registers, which may affect confidentiality or integrity in a worst-case DMA-style interpretation. However, the patch does not show a concrete arbitrary memory access primitive or a proven privilege escalation path, so the conservative result remains borderline and the paranoid result is Actionable Moderate rather than Strong Important. ## 5. One-sentence report phrase A local race in the Tegra DRM gr2d/gr3d probe path can expose the HOST1X client before address register maps are initialized, allowing early userspace job submission while GPU address validation state is incomplete and potentially causing DoS or security-relevant DMA validation bypass. ## 6. Manual review recommendation MANUAL CHECK REQUIRED This should not be auto-closed because the affected data is an address register map in a GPU job submission path, and the worst-case impact depends on whether an early job can program address-bearing registers before normal validation is ready. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: drm/tegra: gr2d/gr3d: Initialize address register map before HOST1X client is registered [ Upstream Commit: 6e22d5ad61cfa38aa53fab86a530113aff6a3619 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6e22d5ad61cfa38aa53fab86a530113aff6a3619 Changed files: drivers/gpu/drm/tegra/gr2d.c drivers/gpu/drm/tegra/gr3d.c Diff excerpt: Not included in this email. See the upstream URL for the full patch. Full patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6e22d5ad61cfa38aa53fab86a530113aff6a3619 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80883 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80883 The original CVE announcement normally does not include a security-level estimate. In particular, it may not contain a CVSS assessment, an impact level, or enough information to determine whether the reported bug is a practically relevant security issue. One purpose of this parallel CVE list is to provide that missing technical and prioritization information. The original goal of the AL-KERNEL project was to prioritize Linux kernel CVE analysis automatically before manual review. The system can also help identify non-security issues that may be suitable for automatic closure. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. The first analysis stage combines an autonomous classifier with additional LLM-based analysis. The autonomous classifier runs locally on a CPU and is based on a backpropagation neural network. Together, these mechanisms produce a technical vulnerability description, identify likely weakness types, estimate CVSS severity, and provide input for ActionableScore. Two CVSS estimates are retained because incomplete kernel vulnerability information often permits more than one defensible interpretation: Conservative CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7 The conservative vector represents a lower-impact interpretation. The Best/paranoid vector intentionally represents a plausible upper-bound interpretation and should not automatically be treated as demonstrated real-world impact. CVSS may also need to be adjusted for a particular Linux deployment, because actual reachability, privileges, enabled kernel configuration, hardware, namespaces, exposed device nodes, and other environmental conditions can differ significantly between systems. A separate ActionableScore mechanism evaluates practical remediation urgency. Its analysis may include reachability, attack prerequisites, subsystem exposure, memory-corruption characteristics, denial-of-service reliability, and possible confidentiality, integrity, or privilege-escalation impact. Conservative ActionableScore: 4 Paranoid ActionableScore: 6 The final base severity is taken directly from the second tab-separated field of the AL-KERNEL classification result. ActionableScore does not replace or independently override that final AL-KERNEL decision, and if ActionableScore adjusted impact level of ALKERNEL, then you would see self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7. For an AL-KERNEL result of MODERATE, this report uses the following additional presentation split: ActionableScore below 5 -> MODERATE REGULAR ActionableScore 5 or more -> MODERATE 7.0 The distinction between MODERATE REGULAR and MODERATE 7.0 makes it possible to identify Moderate issues that should receive manual analysis and fixes before lower-priority MODERATE REGULAR issues. In many cases, MODERATE REGULAR fixes may wait for a later rebase or routine update. There is one override in which MODERATE REGULAR becomes MODERATE 7.0 even when the ActionableScore is below 5. When the AL-KERNEL result contains the KPANIC flag, a MODERATE result is always presented as MODERATE 7.0. The KPANIC flag selected with few regexps without usage of AI at all, so it helps to detect cases when Kernel Crash happens and similar (to filter False-Negative results from the LLM usage). KPANIC indicates that a reliable kernel crash, kernel panic, or similarly serious kernel availability impact was identified by the classification workflow. AL-KERNEL base severity for this report: MODERATE KPANIC detected for this report: YES Published priority for this report (same as in Subject): MODERATE 7.0 These results are intended to support engineering triage. They are machine-generated estimates, and cases marked for manual review should be validated by a human security engineer before final disposition. For more info read docs linked from here: https://kernelcve.org/ (and you can submit you own patch there to generate such a report for non-existant CVE-id yet). Note that in many cases this AI tool selects higher severity, than real is (means you can expect Importants instead of Moderate 7.0 or Moderates 7.0 instead of regular Moderates). If you see such cases, please use reply email interface to add additional manual analyses info to this particular CVE. And please, please, let me know when you see Lows instead of Importants or Important instead of Low (because particular for such cases I need to tune this AI tool to make it better for this one and next similar). My contact email for such notifications is alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).