From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-53060][LOW] dm cache metadata: fix memory leak on metadata abort retry [ Upstream Date: Fri, 26 Jun 2026 07:15:25 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-53060 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: 14f60e957f34f95a626caec76a8fae88cf4c397f List-Id: CVE: CVE-2026-53060 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: dm cache metadata: fix memory leak on metadata abort retry [ Upstream Commit: 14f60e957f34f95a626caec76a8fae88cf4c397f Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=14f60e957f34f95a626caec76a8fae88cf4c397f Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53060 Analysis date: Fri, 26 Jun 2026 07:15:25 -0400 ActionableScore: 2 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like, autoclose candidate Manual review required: YES Summary: A missing cleanup path in dm_cache_metadata_abort can leak a temporary block manager during metadata abort retry after a failed write lock, causing a privileged local device-mapper resource leak with possible cumulative DoS but no supported memory corruption or privilege escalation primitive. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53060 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53060 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: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-53060 LOW CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'dm_cache_metadata_abort can leak a temporary block manager when metadata abort retry reaches a failed write lock path after the metadata becomes read-only or fail_io is set. The issue is a local device mapper control plane resource leak rather than a packet or remote storage data path bug. For the CVSS the PR:L is used for the paranoid case because some environments may delegate device mapper control to a storage service or reduced capability admin account, while a normal host usually requires CAP_SYS_ADMIN. The issue is not network reachable. Impact is denial of service through cumulative kernel memory exhaustion if the abort and reload sequence can be repeated. No direct confidentiality or integrity impact is supported because the primitive is a memory leak without UAF, OOB access, or arbitrary write.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like, autoclose candidate (with actual score 1) MAYBE DEADLOCK DISK RACE LEAK HARDWARE LINUS 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, autoclose candidate**:: ## 2. Signal breakdown Conservative scoring: * Important filesystem/storage path: +1. The bug is in dm-cache metadata abort handling. * Requires admin/root/CAP_SYS_ADMIN in typical deployments: -2. Reproducing the issue requires dmsetup table reload, suspend, resume, and cache device management. * Rare and difficult-to-reach configuration: -1. The reliable reproducer needs dm-cache, metadata I/O failure or read-only metadata state, and repeated abort/reload behavior. * Clamp to 0 because the total is negative. Paranoid scoring: * Availability impact realistic: +1. Repeated retries can leak kernel memory and could theoretically lead to resource exhaustion. * Important filesystem/storage path: +1. The affected code is in device-mapper cache metadata management. * No memory corruption signal. The patch fixes a missing cleanup path for a temporary block manager, not UAF, OOB access, double free, or arbitrary write. * No confidentiality or integrity signal. There is no demonstrated disclosure, overwrite, metadata corruption, or privilege boundary bypass. ## 3. Reachability analysis The bug is locally reachable through device-mapper cache management operations. In normal deployments, creating dm-cache devices, reloading tables, suspending and resuming targets, and forcing metadata error states require CAP_SYS_ADMIN or equivalent storage-management privileges. Namespaces and containers usually do not make this reachable unless the container or service is explicitly delegated access to host device-mapper control. A reduced-capability storage service could make the paranoid PR interpretation more relevant, but this is not a normal unprivileged user path. The path is not network reachable. It is not in a packet-processing or remote storage protocol parser. Triggering requires a specific dm-cache setup and metadata failure or read-only state. ## 4. Severity interpretation This behaves like an ordinary Moderate or Low-like resource leak rather than an Important-class kernel vulnerability. The realistic impact is cumulative memory loss from repeated privileged control-plane operations. Theoretical worst case is local DoS through sustained kernel memory exhaustion. The patch and call path do not support privilege escalation, memory corruption, information disclosure, page-cache corruption, or filesystem metadata corruption. The leak appears small per operation and requires privileged orchestration, so it should not be treated as actionable Moderate unless a deployment delegates device-mapper control to less trusted users. ## 5. One-sentence report phrase A missing cleanup path in dm_cache_metadata_abort can leak a temporary block manager during metadata abort retry after a failed write lock, causing a privileged local device-mapper resource leak with possible cumulative DoS but no supported memory corruption or privilege escalation primitive. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED. NO MANUAL CHECK REQUIRED COULD BE AUTOCLOSED. Reason: this is a privileged local resource leak with no memory corruption, no network reachability, no security-boundary bypass, and only cumulative availability impact under special dm-cache metadata failure conditions. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: dm cache metadata: fix memory leak on metadata abort retry [ Upstream Commit: 14f60e957f34f95a626caec76a8fae88cf4c397f Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=14f60e957f34f95a626caec76a8fae88cf4c397f Changed files: drivers/md/dm-cache-metadata.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=14f60e957f34f95a626caec76a8fae88cf4c397f ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53060 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53060 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:H/UI:N/S:U/C:N/I:N/A:L The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 5.5 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).