From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-90065][LOW] net/smc: release the internal TCP sock on IPPROTO_SMC socket creation failure [ Upstream Date: Thu, 17 Sep 2026 21:31:39 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-90065 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: 2f4ece7fed6d915ec64b7735962c0d84d6261032 List-Id: CVE: CVE-2026-90065 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: net/smc: release the internal TCP sock on IPPROTO_SMC socket creation failure [ Upstream Commit: 2f4ece7fed6d915ec64b7735962c0d84d6261032 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2f4ece7fed6d915ec64b7735962c0d84d6261032 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90065 Analysis date: Thu, 17 Sep 2026 21:31:39 -0400 ActionableScore: 2 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90065 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90065 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-2026-90065 LOW https://www.kernelcve.org/list/?q=CVE-2026-90065 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: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 'A resource leak in IPPROTO_SMC socket creation can occur when proto init creates the internal TCP clcsock but a later socket create hook fails the operation. A local process can repeatedly trigger failed socket(AF_INET, SOCK_STREAM, IPPROTO_SMC) calls under a deny policy such as BPF_CGROUP_INET_SOCK_CREATE, causing one tcp_sock to be leaked per failure and potentially exhausting kernel memory over time. For the CVSS the PR:L is used because reliable triggering requires a local process with access to the SMC socket interface and a local policy path that rejects creation after init. The issue is not network reachable because it is triggered through local socket creation and cgroup BPF policy handling rather than remote packet traffic. Impact is denial of service through resource exhaustion. No confidentiality or integrity impact is assigned because the observable primitive is a memory leak without evidence of UAF, OOB access, information disclosure, or arbitrary write.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES BPF LEAK INCREASED_FROM_LOW_BASED_ON_HIGHCVSSSCORE DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=NO NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 2 * Conservative score: 2 * Raw paranoid score: 2 * Paranoid score: 2 * Final recommended bucket: **Ordinary Moderate**:: No floor or cap changed the score. 2. Signal breakdown Positive signals: * +1 Concrete persistent kernel resource/reference leak. The internal TCP clcsock is created during IPPROTO_SMC socket initialization and is not released when socket creation fails after proto init. * +1 Below-host-admin local trigger. The supplied context states that an unprivileged task able to attach a deny-all BPF_CGROUP_INET_SOCK_CREATE program to its own cgroup can repeatedly trigger failed IPPROTO_SMC socket creation. Negative or non-awarded signals: * +0 Real UAF. The vulnerable behavior is a leaked tcp_sock, not a stale post-free use. * +0 Concrete repeated release/refcount. There is no first release followed by a second lifetime mutation on the same dangling reference. * +0 Reliable kernel crash. No immediate panic or NULL dereference is established by the vulnerable path. * +0 Extra availability. Unbounded growth supports DoS risk, but it is the consequence of the same resource leak and is not counted again as a separate signal. * +0 Confidentiality and integrity. No information disclosure, UAF, OOB access, arbitrary write, or ownership bypass is established. * +0 Remote reachability. The trigger is local socket creation plus local cgroup BPF policy behavior, not remote packet traffic. * +0 Strong LPE or weak LPE. No controlled reclaim, object replacement, refcount takeover, callback influence, or privilege-escalation primitive is shown. * +0 BPF strong control-plane escalation. BPF is involved as the failure hook, but the vulnerable primitive is still only a resource leak in SMC socket cleanup. 3. Reachability analysis The trigger is local. The supplied context describes a task that can attach a deny-all BPF_CGROUP_INET_SOCK_CREATE program to its own cgroup and then repeatedly call socket(AF_INET, SOCK_STREAM, IPPROTO_SMC), causing the post-init creation failure. Host-admin-equivalent privilege is not positively established as required by the supplied scenario, so HostAdminRequired=NO. The exact namespace and capability details for loading and attaching the cgroup BPF program are not fully resolved from the patch alone, so NamespaceScopedPrivilege=UNKNOWN. There is no direct network trigger. IPPROTO_SMC is a socket protocol path, but the vulnerable operation is failed local socket creation, not packet processing. No special physical hardware is required by the evidence. No race is required. Repeated attempts are cheap once the local failure condition exists. 4. Primitive and severity interpretation The exact primitive is a persistent kernel resource leak: one internal TCP socket object can be leaked for each failed IPPROTO_SMC socket creation after proto init has already created clcsock. This is not active structured UAF and not fixed stale storage. The patch also unhashes the SMC socket before releasing clcsock because smc_diag can walk the hash and dereference smc->clcsock. That ordering prevents a possible unsafe observation in the new destroy path, but the original vulnerability evidenced here is a missing release, not a demonstrated UAF. PrimitiveClass=CLASS_C because the established consequence is resource exhaustion DoS without an independently useful corruption primitive. The demonstrated consequence is kernel memory growth over repeated failures. The speculative consequence is eventual denial of service due to memory exhaustion. There is no meaningful leverage beyond resource exhaustion. ImportantCandidate=NO because there is no memory corruption, repeated lifetime mutation, authorization bypass, COW violation, or demonstrated LPE. AutoDowngradeAllowed=YES because the issue is a pure resource leak and does not leave unresolved exploitation leverage that would be lost by ordinary Moderate handling. 5. One-sentence report phrase A local IPPROTO_SMC socket creation failure can leak one internal TCP clcsock per failed call when a cgroup socket-create hook rejects the socket after proto init, allowing repeated local resource exhaustion but not showing memory corruption or privilege escalation. 6. Manual review recommendation NO MANUAL CHECK NEEDED Reason: the established primitive is a concrete resource leak with possible DoS through accumulation, but there is no UAF, repeated refcount mutation, arbitrary write, information leak, authorization bypass, or remote trigger. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: net/smc: release the internal TCP sock on IPPROTO_SMC socket creation failure [ Upstream Commit: 2f4ece7fed6d915ec64b7735962c0d84d6261032 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2f4ece7fed6d915ec64b7735962c0d84d6261032 Changed files: net/smc/smc_inet.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=2f4ece7fed6d915ec64b7735962c0d84d6261032 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-90065 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-90065 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).