From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-53375][MODERATE 7.0] drm/amdgpu/vce: Prevent partial address patches Date: Sun, 19 Jul 2026 06:43:44 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-53375 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: 3 X-AL-KERNEL-Commit: 2d66d1f5d8c0434e9a5ad21cc6eaf3a5e32141d5 List-Id: CVE: CVE-2026-53375 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: drm/amdgpu/vce: Prevent partial address patches Commit: 2d66d1f5d8c0434e9a5ad21cc6eaf3a5e32141d5 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2d66d1f5d8c0434e9a5ad21cc6eaf3a5e32141d5 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53375 Analysis date: Sun, 19 Jul 2026 06:43:44 -0400 ActionableScore: 5 ActionableScore lower bound: 3 Actionable bucket: Actionable Moderate at minimum Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53375 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53375 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-2026-53375 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:H/I:H/A:H';*CWE-20;*CWE-787;CWE-823;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H';BEST CVSS score: '7.8';DESCR 'amdgpu VCE command submission did not reject relocation records where only one 32 bit half of a patched address is inside the IB bounds. A local user with access to the AMDGPU DRM render or card device may craft a command stream that causes partial address patching and a bad address to be passed to firmware. For the CVSS the PR:L is used because reliable triggering requires local code execution with access to the GPU submission interface, but not full administrative privileges in common desktop or compute deployments. The issue is not network reachable. Impact is at least GPU reset or kernel denial of service, and the out of bounds or bad address patching pattern is a plausible memory corruption candidate that should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4) SKIP CVE-2026-53375 UNKNOWN SKIP No affected files built, so skip this CVE NO - - unknown MAYBE OOB SIMPLEFIX HARDWARE INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCORELOWERTHAN7 DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== 1. ActionableScore ActionableScore=5 ActionableScoreLower=3 * Conservative score: 3 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate at minimum** 2. Signal breakdown * Local unprivileged trigger: +1. A local process with access to the AMDGPU DRM submission interface or render node may be able to submit the affected VCE command stream. * Constrained kernel or GPU buffer overwrite candidate: +1. The patch adds bounds checks for `lo` and `hi` before address patching, so the bug is more than pure bookkeeping, but the write appears constrained to VCE relocation patching and the payload is address-derived rather than an arbitrary attacker-chosen byte stream. * Reliable kernel crash or strong DoS: +1. A bad address passed to firmware can plausibly cause GPU hang, reset, or driver level denial of service. * Privileged kernel or device-management corruption path: +1 in paranoid scoring. The affected path is GPU firmware command submission and address patching, which is a trusted device interaction path. * Weak LPE concern: +1 in paranoid scoring only. Partial address patching into a firmware-consumed command stream is a plausible corruption sink, but no concrete host kernel arbitrary write, reclaim primitive, or privilege escalation chain is shown. * Constrained primitive or no attacker-controlled payload: -1. The patch does not show a fully attacker-controlled target and payload primitive. 3. Reachability analysis The likely trigger is local command submission through AMDGPU VCE paths. This does not appear network reachable. In typical desktop or GPU compute deployments, DRM render node access may be available to non-root users in the video or render group, so PR:L is the practical interpretation rather than PR:H. Containers may inherit exposure if GPU devices are passed through. The path is hardware and feature dependent because it requires AMDGPU VCE support, so exposure is narrower than core kernel networking or filesystem code, but it is still reachable through ordinary GPU userspace interfaces when the device is available. Call-site confidence: medium. The provided patch shows the validation point and affected helper, but not the full caller chain or the final writes into the IB. 4. Severity interpretation This is not an ordinary Low issue because it involves address patching in a GPU firmware command stream and missing bounds validation for relocation indices. The conservative interpretation is a local DoS or GPU reset class issue with constrained corruption characteristics. The paranoid interpretation treats the partial address patch as a weak device memory corruption candidate that deserves manual review, but the patch does not justify assuming arbitrary host kernel code execution or a strong LPE primitive. 5. One-sentence report phrase A local user with access to the AMDGPU VCE command submission path may craft relocation indices where only one address half is valid, causing partial address patching and a bad firmware-consumed address that can lead to GPU or kernel denial of service and warrants manual review for constrained corruption impact. 6. Manual review recommendation MANUAL CHECK REQUIRED Manual review is required because the bug is in a GPU firmware address patching path and may represent more than a simple validation error, even though the demonstrated impact is closer to constrained corruption or DoS than proven privilege escalation. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: drm/amdgpu/vce: Prevent partial address patches Commit: 2d66d1f5d8c0434e9a5ad21cc6eaf3a5e32141d5 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2d66d1f5d8c0434e9a5ad21cc6eaf3a5e32141d5 Commit description: In the case that only one of lo/hi is valid, the patching could result in a bad address written to in FW. Signed-off-by: Benjamin Cheng Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Changed files: drivers/gpu/drm/amd/amdgpu/amdgpu_vce.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=2d66d1f5d8c0434e9a5ad21cc6eaf3a5e32141d5 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53375 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53375 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:H The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7.8 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: 3 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).