From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80703][MODERATE 7.0] drm/amdkfd: Fix missing authorization check in KFD_IOC_DBG_TRAP_DISABLE Date: Fri, 28 Aug 2026 05:34:29 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80703 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: ce813614f63b020a826071276a92f2cfae7cba79 List-Id: CVE: CVE-2026-80703 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: drm/amdkfd: Fix missing authorization check in KFD_IOC_DBG_TRAP_DISABLE Commit: ce813614f63b020a826071276a92f2cfae7cba79 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ce813614f63b020a826071276a92f2cfae7cba79 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80703 Analysis date: Fri, 28 Aug 2026 05:34:29 -0400 ActionableScore: 5 ActionableScore lower bound: unknown Actionable bucket: Actionable Moderate at minimum Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80703 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80703 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: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-80703 MODERATE CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L';CWE-862;CWE-284;CWE-285;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L';BEST CVSS score: '5.3';DESCR 'A missing authorization check in the AMD KFD debug trap ioctl allowed KFD_IOC_DBG_TRAP_DISABLE to bypass the normal cross process ptrace validation. A local user with access to /dev/kfd could disable another process GPU debug session without being the ptrace parent or the registered debugger process. For the CVSS the PR:L is used because reliable triggering requires a local user or service context with access to the KFD device, but not full administrator privileges. The issue is not network reachable and is triggered through a local device ioctl rather than packet traffic. Impact is mainly unauthorized interference with GPU debugging state, causing limited integrity and availability impact for the target debug session. No direct memory corruption or kernel privilege escalation primitive is indicated by the code change.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5) SKIP CVE-2026-80703 UNKNOWN SKIP No affected files built, so skip this CVE NO - - unknown MAYBE SIMPLEFIX HARDWARE INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK DECREASED_TO_MODERATEREG_BASED_ON_FALSEPOSCHECKOFKP - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 1. ActionableScore * Conservative score: 5 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate at minimum**:: 2. Signal breakdown * Local unprivileged trigger: +1. A local user or service with access to /dev/kfd can issue the affected ioctl without full root privileges in typical GPU compute deployments. * Security-boundary bypass with practical sensitive-object access: +2. The bug bypasses ptrace/debugger ownership authorization for cross-process GPU debug control. * Integrity impact plausible: +1. An unauthorized process can alter another process debug-session state by disabling it. * Availability impact realistic: +1. The target debug session can be terminated, disrupting debugging or GPU-compute observability. * No memory corruption: +0. The patch only changes authorization logic and does not show UAF, OOB access, arbitrary write, refcount abuse, or callback control. * Not network reachable: +0. The trigger is a local /dev/kfd ioctl. 3. Reachability analysis The bug is reachable by a local process with /dev/kfd access. This is commonly granted to GPU users through render or video style device permissions, so PR:L is more appropriate than PR:H for practical triage. Namespaces or containers may matter if the KFD device is passed through to a container or workload. The path is not remotely network-triggerable and requires an active or targetable GPU debug session. 4. Severity interpretation This behaves like an access-control bypass rather than memory corruption. There is no evidence of kernel privilege escalation, but bypassing ptrace-like authorization for another process debug session is security-relevant and should not be treated as an ordinary low-risk cleanup. The practical impact is limited integrity and availability against GPU debug state, with possible limited confidentiality concern in paranoid CVSS if debug control exposes process state in some deployments. 5. One-sentence report phrase A missing authorization check in the AMD KFD debug trap ioctl allowed a local user with /dev/kfd access to disable another process GPU debug session without being the ptrace parent or registered debugger, causing unauthorized interference with debug state. 6. Manual review recommendation MANUAL CHECK RECOMMENDED. YES REQUIRES MANUAL CHECK. This is not memory corruption, but it is a local authorization bypass across process debug boundaries and depends on real /dev/kfd exposure and GPU debug-session usage. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: drm/amdkfd: Fix missing authorization check in KFD_IOC_DBG_TRAP_DISABLE Commit: ce813614f63b020a826071276a92f2cfae7cba79 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ce813614f63b020a826071276a92f2cfae7cba79 Commit description: Prevent unauthorized termination of active GPU debug sessions. Previously, users with /dev/kfd access could terminate another process's debug session without proper ownership or ptrace authorization. Signed-off-by: Gang Ba Reviewed-by: Kent Russell Signed-off-by: Alex Deucher (cherry picked from commit 4db4c5f ) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Changed files: drivers/gpu/drm/amd/amdkfd/kfd_chardev.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=ce813614f63b020a826071276a92f2cfae7cba79 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80703 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80703 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:L/PR:L/UI:N/S:U/C:N/I:L/A:L The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L The Best / paranoid CVSS score: 5.3 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: unknown Paranoid ActionableScore: 5 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: NO 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).