From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-68249][LOW] drm/amdgpu/sdma5.0: replace BUG_ON() with WARN_ON() Date: Mon, 10 Aug 2026 13:37:28 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-68249 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: unknown X-AL-KERNEL-Commit: f6212bc1bbd936fd9f7d77168b0c8b0019477b64 List-Id: CVE: CVE-2026-68249 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: drm/amdgpu/sdma5.0: replace BUG_ON() with WARN_ON() Commit: f6212bc1bbd936fd9f7d77168b0c8b0019477b64 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f6212bc1bbd936fd9f7d77168b0c8b0019477b64 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68249 Analysis date: Mon, 10 Aug 2026 13:37:28 -0400 ActionableScore: 2 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68249 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68249 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-2026-68249 LOW CHECK WITH IMPACT FROM ORIG NN LOW 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-617;CWE-754;CWE-703;BEST CVSS score: '4.7';DESCR 'A reachable BUG_ON in the AMDGPU SDMA v5.0 fence emit path could convert an unexpected misaligned fence address into a kernel panic. A local user with access to the GPU driver interface may indirectly reach this path through GPU work submission, but the fence address appears to be driver managed rather than directly attacker controlled. For the CVSS the PR:L is used because a local user context with access to the DRM GPU interface is the most plausible trigger model for the paranoid score. The issue is not network reachable. Impact is denial of service only via kernel crash, with no concrete evidence of information disclosure, integrity impact, UAF, OOB access, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) SKIP CVE-2026-68249 UNKNOWN SKIP No affected files built, so skip this CVE NO - - unknown MAYBE WARNONLY SIMPLEFIX HARDWARE - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 1. ActionableScore * Conservative score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like**:: 2. Signal breakdown * Local unprivileged trigger: +1. A local user with access to AMDGPU DRM interfaces may plausibly reach SDMA fence emission indirectly through GPU work submission. * Reliable kernel crash / strong DoS: +1. If the misaligned fence address condition is reached, BUG_ON() causes an immediate kernel panic. * Hard or unreliable trigger: -1. The address appears to be driver-managed rather than directly attacker-controlled, and the patch does not show a straightforward user-controlled path to set the low address bits. * Broad/default/common subsystem: +1. AMDGPU is a commonly deployed GPU driver, but the affected path is device-specific and not a core kernel-wide interface. * No memory-corruption signal. The patch only replaces BUG_ON() with WARN_ON() and does not show UAF, OOB access, arbitrary write, refcount misuse, object lifetime corruption, or privilege-escalation primitive. 3. Reachability analysis A local user with access to the GPU device nodes is the most plausible attacker model. No network reachability is present. Namespaces or containers may matter only if GPU device access is delegated into the container. The vulnerable condition depends on reaching SDMA fence emission with a misaligned internal fence address, which is not shown to be directly controllable by userspace. Call-site confidence: medium, because the changed function is visible but the full caller chain and address provenance are not included. 4. Severity interpretation This behaves like an ordinary Moderate or Low-like local DoS issue. The demonstrated impact is kernel panic from a reachable assertion. There is no supported evidence of memory corruption, confidentiality impact, integrity impact, or privilege escalation. Theoretical concern is limited to whether userspace can reliably force the invalid alignment condition, but the patch context does not support upgrading it beyond DoS. 5. One-sentence report phrase A reachable BUG_ON() in the AMDGPU SDMA v5.0 fence emission path could allow a local GPU user to trigger a kernel panic if an unexpected misaligned fence address is reached, but no memory corruption or privilege escalation primitive is shown. 6. Manual review recommendation NO MANUAL CHECK NEEDED Reason: this is a local DoS-only assertion removal with low ActionableScore, no network exposure, no concrete memory corruption primitive, and no evidence of confidentiality or integrity impact. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: drm/amdgpu/sdma5.0: replace BUG_ON() with WARN_ON() Commit: f6212bc1bbd936fd9f7d77168b0c8b0019477b64 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f6212bc1bbd936fd9f7d77168b0c8b0019477b64 Commit description: There's no need to crash the kernel for these cases. Reviewed-by: Vitaly Prosyak Signed-off-by: Alex Deucher (cherry picked from commit 8d144a0 ) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Changed files: drivers/gpu/drm/amd/amdgpu/sdma_v5_0.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=f6212bc1bbd936fd9f7d77168b0c8b0019477b64 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-68249 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68249 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: Not available 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: unknown 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).