From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-46038][LOW] net: qrtr: ns: Free the node during ctrl_cmd_bye() Date: Wed, 27 May 2026 12:15:50 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-46038 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: ff78ed177a66763085e3214d6fbe13ca8f0b3f11 List-Id: CVE: CVE-2026-46038 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: net: qrtr: ns: Free the node during ctrl_cmd_bye() Commit: ff78ed177a66763085e3214d6fbe13ca8f0b3f11 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ff78ed177a66763085e3214d6fbe13ca8f0b3f11 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46038 Analysis date: Wed, 27 May 2026 12:15:50 -0400 ActionableScore: 2 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: QRTR nameserver failed to free node objects after BYE messages, allowing local clients to leak kernel memory and cause DoS-only resource exhaustion. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-46038 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46038 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-2026-46038 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:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'QRTR nameserver did not free node objects after processing BYE packets. A local client could repeatedly create and remove random QRTR nodes and make the kernel retain qrtr_node memory, causing resource pressure or denial of service. For the CVSS the PR:L is used because a local process with access to QRTR can influence node lifecycle messages, but the issue is not reachable over normal IP networking. The issue does not involve UAF, out of bounds write, arbitrary write, information disclosure, or privilege escalation. Impact is denial of service only through memory leak and resource exhaustion, with practical exposure depending on whether untrusted local workloads can access QRTR on the target platform.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2) YES SIMPLEFIX LEAK LINUS PACKET INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ## 1. ActionableScore * Conservative score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate / Low-like**:: ## 2. Signal breakdown Triggered signals: * Local unprivileged trigger: +1 A local process with access to QRTR can influence node lifecycle messages, including BYE handling. * Resource exhaustion / DoS: +1 Unfreed `qrtr_node` objects can accumulate and consume kernel memory. * Availability impact realistic: +1 Repeated node creation and BYE processing can degrade QRTR nameservice or create memory pressure. Subtracting signals: * Platform/configuration-dependent exposure: -1 QRTR is mainly relevant on Qualcomm-style systems and is not universally exposed to local workloads. No signals apply for remote reachability, memory corruption, UAF, OOB write, arbitrary write, information disclosure, privilege escalation, or security-boundary bypass. ## 3. Reachability analysis The issue is local-only. A client must be able to use QRTR nameservice and create or remove node entries. It is not reachable through normal IP networking. Namespaces and containers matter only if QRTR access is exposed to untrusted workloads. Practical exposure depends on whether the platform uses QRTR and allows local clients to send node lifecycle messages. ## 4. Severity interpretation This behaves like an ordinary Moderate or Low-like resource leak. The patch ensures that BYE processing erases the node from the XArray and frees the memory. Theoretical impact is memory pressure or nameservice disruption. Realistic evidence does not support memory corruption, information disclosure, or privilege escalation. ## 5. One-sentence report phrase QRTR nameserver failed to free node objects after BYE messages, allowing local clients to leak kernel memory and cause DoS-only resource exhaustion. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This is a local platform-specific resource leak with no supported memory corruption, remote exposure, or privilege-escalation primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: net: qrtr: ns: Free the node during ctrl_cmd_bye() Commit: ff78ed177a66763085e3214d6fbe13ca8f0b3f11 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ff78ed177a66763085e3214d6fbe13ca8f0b3f11 Commit description: A node sends the BYE packet when it is about to go down. So the nameserver should advertise the removal of the node to all remote and local observers and free the node finally. But currently, the nameserver doesn't free the node memory even after processing the BYE packet. This causes the node memory to leak. Hence, remove the node from Xarray list and free the node memory during both success and failure case of ctrl_cmd_bye(). Cc: stable@vger.kernel.org Fixes: 0c2204a ("net: qrtr: Migrate nameservice to kernel from userspace") Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20260409-qrtr-fix-v3-3-00a8a5ff2b51@oss.qualcomm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman Changed files: net/qrtr/ns.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=ff78ed177a66763085e3214d6fbe13ca8f0b3f11 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-46038 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46038 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: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: 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).