From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-43367][LOW] drm/amd: Fix a few more NULL pointer dereference in device cleanup Date: Sat, 01 Aug 2026 12:29:02 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-43367 X-AL-KERNEL-Priority: LOW X-AL-KERNEL-Severity: LOW X-AL-KERNEL-Base-Severity: LOW X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 2 X-AL-KERNEL-ActionableScore-Lower: 0 X-AL-KERNEL-Commit: 38f1640db7f8bf57b9e09c5b0b8b205a598f1b3e List-Id: CVE: CVE-2026-43367 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: drm/amd: Fix a few more NULL pointer dereference in device cleanup Commit: 38f1640db7f8bf57b9e09c5b0b8b205a598f1b3e Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=38f1640db7f8bf57b9e09c5b0b8b205a598f1b3e Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-43367 Analysis date: Sat, 01 Aug 2026 12:29:02 -0400 ActionableScore: 2 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: A NULL pointer dereference in AMDGPU cleanup can crash the kernel on unsupported or partially initialized hardware when cleanup code accesses a missing IP block version pointer. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-43367 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-43367 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: LOW 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-2026-43367 LOW 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:N/I:N/A:H';**CWE-476;CWE-703;CWE-754;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'A NULL pointer dereference can occur in the AMDGPU device cleanup path because amdgpu_device_ip_fini_early() and amdgpu_device_ip_fini() may access ip_blocks version when it is NULL on unsupported or partially initialized hardware. The realistic impact is a local denial of service through a kernel crash during driver cleanup, device removal, or recovery after failed initialization. For the CVSS the PR:L is used only in the paranoid interpretation where a local user can indirectly trigger GPU reset or cleanup paths through delegated device access. The base case is closer to PR:H because reliable triggering normally requires administrative control over the driver or hardware state. The issue is not network reachable and there is no concrete UAF, OOB access, or arbitrary write primitive indicated by the changed code.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) MAYBE NULLPTR SIMPLEFIX HARDWARE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ActionableScoreLower=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like** ## 2. Signal breakdown Conservative signals: * Reliable kernel crash / strong DoS: +1. The patch prevents NULL dereference in AMDGPU cleanup paths. * Requires admin/root/CAP level control in typical deployments: -2. Reliable triggering usually needs driver unload, device removal, failed probe handling, recovery, or hardware state control. * Physical-only or rare hardware-only condition: -2. The commit explicitly says this occurs on unsupported hardware with NULL version pointers. * Score floored at 0. Paranoid signals: * Local unprivileged trigger: +1. In some deployments a local user with DRM device access might indirectly trigger GPU reset or recovery paths. * Reliable kernel crash / strong DoS: +1. Cleanup may dereference NULL and crash the kernel. * Rare hardware / unsupported hardware dependency limits practical exposure. * No memory corruption, UAF, OOB write, callback hijack, or arbitrary write is shown. ## 3. Reachability analysis The bug is local and hardware dependent. It affects AMDGPU cleanup paths such as `amdgpu_device_ip_fini_early()` and `amdgpu_device_ip_fini()` when an IP block has a NULL `version` pointer on unsupported or partially initialized hardware. Typical reliable triggering requires administrative control over the driver, device lifecycle, or hardware state. A weaker paranoid scenario is possible if a local user can indirectly force GPU recovery or reset through exposed DRM interfaces, but the patch does not show a strong unprivileged trigger. Namespaces and containers generally do not make this broadly reachable unless the GPU device node is delegated into the container. The path is not network reachable. Call-site confidence: high. The affected cleanup functions and dereferenced fields are visible in the patch. ## 4. Severity interpretation This behaves like a Low-like or ordinary Moderate local DoS issue, not an Important-class kernel vulnerability. The primitive is a NULL pointer dereference only. There is no evidence of UAF, stale object reuse, attacker-controlled reclaim, OOB write, type confusion, refcount misuse, or privilege escalation. Theoretical impact is kernel crash. Realistic exploitation is limited by unsupported hardware or partial initialization conditions and by the need to reach device cleanup paths. ## 5. One-sentence report phrase A NULL pointer dereference in AMDGPU cleanup can crash the kernel on unsupported or partially initialized hardware when cleanup code accesses a missing IP block version pointer. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be auto-closed for urgent triage purposes because it is a hardware-dependent NULL dereference DoS with no concrete memory corruption or privilege escalation primitive shown by the patch. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: drm/amd: Fix a few more NULL pointer dereference in device cleanup Commit: 38f1640db7f8bf57b9e09c5b0b8b205a598f1b3e Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=38f1640db7f8bf57b9e09c5b0b8b205a598f1b3e Commit description: I found a few more paths that cleanup fails due to a NULL version pointer on unsupported hardware. Add NULL checks as applicable. Fixes: 39fc2bc ("drm/amdgpu: Protect GPU register accesses in powergated state in some paths") Reviewed-by: Alex Deucher Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher (cherry picked from commit f5a05f8 ) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Changed files: drivers/gpu/drm/amd/amdgpu/amdgpu_device.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=38f1640db7f8bf57b9e09c5b0b8b205a598f1b3e ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-43367 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-43367 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:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.7 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: 0 Paranoid ActionableScore: 2 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: LOW KPANIC detected for this report: NO Published priority for this report (same as in Subject): LOW 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).