From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-53054][MODERATE 7.0] drm/msm: Fix VM_BIND UNMAP locking [ Upstream Date: Fri, 26 Jun 2026 14:56:27 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-53054 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: 7 X-AL-KERNEL-ActionableScore-Lower: 3 X-AL-KERNEL-Commit: 206f812ef140727b75697111391ae320fd8aa652 List-Id: CVE: CVE-2026-53054 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: drm/msm: Fix VM_BIND UNMAP locking [ Upstream Commit: 206f812ef140727b75697111391ae320fd8aa652 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=206f812ef140727b75697111391ae320fd8aa652 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53054 Analysis date: Fri, 26 Jun 2026 14:56:27 -0400 ActionableScore: 7 ActionableScore lower bound: 3 Actionable bucket: Strong Important candidate / Actionable Moderate at minimum Manual review required: YES Summary: A local user with access to the msm DRM VM_BIND ioctl may trigger an UNMAP locking bug that leaves non_NO_SHARE buffer objects unprotected, causing GPUVM state corruption and potential kernel memory corruption. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53054 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53054 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-2026-53054 MODERATE CHECK 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-667;CWE-362;CWE-662;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'A locking bug in the msm DRM VM_BIND UNMAP path can leave some buffer objects involved in an unmap operation without the required reservation lock. This can happen because the unmap locking helper was called with an object offset value instead of the full unmap range, so non_NO_SHARE BOs may be modified while not fully protected by the expected lock context. For the CVSS the PR:L is used because a local user or process needs access to the msm DRM VM_BIND ioctl, typically through a render node or a GPU enabled sandbox. The issue is not network reachable and requires local interaction with the DRM GPU interface. Impact is at least local denial of service through a kernel crash or GPUVM state corruption. For the paranoid score, the highest still defensible interpretation is used because missing locks around GPU VM object lifetime and mapping updates may plausibly lead to memory corruption and possible privilege escalation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 5) SKIP CVE-2026-53054 SKIP No affected files built, so skip this CVE NO - - unknown MAYBE LOCK SIMPLEFIX HARDWARE LINUS KPANIC INCREASED_TO_MODERATE_FROM_LOW_BASED_ON_GUESSCVSS - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=7 ActionableScoreLower=3 ## 1. ActionableScore * Conservative score: 3 * Paranoid score: 7 * Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**:: ## 2. Signal breakdown Conservative signals: * Local unprivileged trigger: +1. A local process with access to the msm DRM render node or GPU VM_BIND ioctl can likely reach this path. * Memory corruption, weak or indirect corruption candidate: +1. The bug is a missing reservation lock on BOs involved in VM_BIND UNMAP, but the patch does not show a direct write primitive. * Local unprivileged high-control kernel data-plane API: +1. VM_BIND gives userspace fine grained control over GPU virtual memory mappings and BO ranges. * Availability impact realistic: +1. Incorrect locking in GPUVM unmap can plausibly cause driver instability, GPUVM state corruption, warnings, hangs, or kernel crash. * Hard or unreliable race / special timing required: -1. Turning missing locking into a security impact likely requires a concurrent operation or timing window. Paranoid additional signals: * Weak LPE concern: +1. Missing BO reservation locking around GPUVM mapping teardown may affect object lifetime and mapping consistency, which is a plausible local privilege escalation concern even without a demonstrated primitive. * Real lifetime corruption: +1. Reservation locks protect object lifetime and concurrent access. Skipping them for some BOs can create stale or inconsistent GPUVM object state. * Confidentiality impact plausible: +1. If the race corrupts GPUVM mappings or object ownership, cross-object or cross-process exposure is technically plausible. * Integrity impact plausible: +1. Incorrectly synchronized GPUVM unmap can plausibly corrupt mappings or allow unintended access to GPU memory objects. Not applied: * Remote reachable: 0. This is not network-triggerable. * Requires admin/root/CAP_SYS_ADMIN: 0. DRM render node access is commonly available to local GPU users and containers with GPU passthrough. * Strong memory corruption primitive: 0. No direct UAF reclaim, arbitrary write, OOB write, or controlled overwrite is shown by the patch. ## 3. Reachability analysis The bug is reachable from the local DRM msm VM_BIND UNMAP path. A normal local user may reach it if they have access to the msm render node, which is common for GPU-enabled desktop, mobile, or sandboxed graphics workloads. Containers can also be relevant if the DRM device node is passed through. The affected path is not default reachable on systems without Qualcomm msm DRM hardware or without the VM_BIND ioctl support. It also specifically affects non_NO_SHARE BOs because _NO_SHARE objects share the VM reservation object that is already locked. There is no realistic network trigger. ## 4. Severity interpretation This is not an ordinary pure DoS cleanup. The one-line fix corrects the range passed to the GPUVM unmap locking helper, and the commit explicitly says that objects involved in UNMAP operations were not always locked. Realistically, the patch proves a synchronization bug that can lead to GPUVM state corruption or crash. The patch does not prove a concrete exploit primitive such as arbitrary write, UAF reclaim, or controlled object confusion. Paranoid interpretation is higher because DRM VM_BIND and GPUVM memory management are high-control local kernel interfaces, and missing reservation locks around BO mapping teardown can plausibly become memory corruption or privilege escalation. This should not be auto-closed without manual review. ## 5. One-sentence report phrase A local user with access to the msm DRM VM_BIND ioctl may trigger an UNMAP locking bug that leaves non_NO_SHARE buffer objects unprotected, causing GPUVM state corruption and potential kernel memory corruption. ## 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: this is a local GPUVM locking race in a high-control DRM memory-management interface, with plausible memory corruption and LPE implications even though the patch does not demonstrate a concrete exploit primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: drm/msm: Fix VM_BIND UNMAP locking [ Upstream Commit: 206f812ef140727b75697111391ae320fd8aa652 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=206f812ef140727b75697111391ae320fd8aa652 Changed files: drivers/gpu/drm/msm/msm_gem_vma.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=206f812ef140727b75697111391ae320fd8aa652 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53054 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53054 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:N/I:N/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: 3 Paranoid ActionableScore: 7 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).