From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-97601][LOW] ieee802154: 6lowpan: fix NULL dereference in lowpan_newlink Date: Fri, 25 Sep 2026 13:24:59 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-97601 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: 1 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 1c7710af7ad9532b534f1c134c11b04dbe4e0e0f List-Id: CVE: CVE-2026-97601 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: ieee802154: 6lowpan: fix NULL dereference in lowpan_newlink Commit: 1c7710af7ad9532b534f1c134c11b04dbe4e0e0f Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1c7710af7ad9532b534f1c134c11b04dbe4e0e0f Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97601 Analysis date: Fri, 25 Sep 2026 13:24:59 -0400 ActionableScore: 1 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-2026-97601 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97601 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-2026-97601 LOW https://www.kernelcve.org/list/?q=CVE-2026-97601 CHECK WITH IMPACT FROM ORIG NN MODERATE 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-476;*CWE-20;CWE-754;BEST CVSS score: '5.5';DESCR 'A NULL pointer dereference in the IEEE802154 6LoWPAN newlink path occurs because TUNSETLINK can change a TUN device to ARPHRD_IEEE802154 without initializing ieee802154_ptr. A local process can then issue an RTM_NEWLINK request that reaches lowpan_newlink and dereferences the NULL pointer, causing a kernel crash and denial of service. For the CVSS the PR:L rating reflects that the attacker needs local network administration capability to configure the TUN device and create the link. In environments that permit untrusted users to create user and network namespaces with scoped CAP_NET_ADMIN, such users may meet this requirement. The issue is not reachable through normal network packet traffic. Impact is denial of service only and the patch does not indicate a memory corruption or privilege escalation primitive.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1) YES NULLPTR SIMPLEFIX HARDWARE LINUS DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 PrimitiveClass=CLASS_C RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=NO AutoDowngradeAllowed=YES 1. ActionableScore * Raw conservative score: 1 * Conservative score: 1 * Raw paranoid score: 1 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown * +1 Reliable kernel crash or strong DoS. The NULL dereference in lowpan_newlink can cause a kernel Oops or panic when the invalid device state reaches the dereference. * +0 No real UAF, stale lifetime violation, double release, refcount mutation, OOB access, arbitrary write, controlled reclaim, or attacker controlled post-free state is established. * +0 No remote reachability. The trigger uses local TUNSETLINK and RTM_NEWLINK control plane operations, not ordinary network packet traffic. * +0 No local unprivileged trigger bonus. CAP_NET_ADMIN or equivalent network administration access is indicated, but the complete privilege boundary is not established by the supplied patch. * +0 No confidentiality or integrity impact. The patch establishes a NULL pointer dereference only and provides no disclosure, write, authorization bypass, or privilege escalation primitive. * +0 No subsystem rarity penalty. IEEE802154 and 6lowpan support may be configuration dependent, but no concrete evidence shows a rare hardware or non-instantiable prerequisite. 3. Reachability analysis The attacker must locally manipulate a TUN device with TUNSETLINK so that its type becomes ARPHRD_IEEE802154 without an initialized ieee802154_ptr, then submit an RTM_NEWLINK operation that invokes lowpan_newlink. The supplied evidence indicates that network administration capability is required for the relevant TUN and rtnetlink configuration operations. However, it does not establish whether every required operation is authorized against the init user namespace, a target network namespace user namespace, or another capability domain. Therefore HostAdminRequired and NamespaceScopedPrivilege are both UNKNOWN. A TUN device and the relevant IEEE802154 6lowpan functionality must be available. No physical IEEE802154 hardware is required by the described trigger because the vulnerable state is created by changing the TUN device link layer type. There is no race condition and no special timing requirement. 4. Primitive and severity interpretation The exact primitive is an invalid state NULL pointer dereference. TUNSETLINK changes the netdevice type to ARPHRD_IEEE802154, but does not initialize ieee802154_ptr. lowpan_newlink previously trusted the device type and dereferenced ieee802154_ptr. This is not an active structured object UAF, fixed stale storage issue, cleanup lifetime bug, refcount bug, or repeated release case. No object is freed, reused, released twice, or consumed after its lifetime ends. The demonstrated consequence is local kernel crash or denial of service. A privilege escalation, kernel memory disclosure, integrity violation, arbitrary kernel write, or security boundary bypass is speculative and unsupported by the patch. The issue is therefore CLASS_C and is not an Important candidate. Automatic downgrade is allowed because the established primitive is limited to a direct NULL dereference with crash only behavior and no unresolved memory corruption or authorization primitive. 5. One-sentence report phrase A local network administration operation can cause lowpan_newlink to dereference an uninitialized ieee802154_ptr after TUNSETLINK changes a TUN device type, resulting in kernel crash denial of service. 6. Manual review recommendation NO MANUAL CHECK NEEDED The patch establishes a direct NULL pointer dereference and local DoS only, without UAF, memory corruption, authorization bypass, remote exposure, or privilege escalation evidence. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ieee802154: 6lowpan: fix NULL dereference in lowpan_newlink Commit: 1c7710af7ad9532b534f1c134c11b04dbe4e0e0f Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1c7710af7ad9532b534f1c134c11b04dbe4e0e0f Commit description: TUNSETLINK allows a TUN device to change its link-layer type to ARPHRD_IEEE802154 without initializing ieee802154_ptr. lowpan_newlink() checks only the device type before dereferencing the pointer, so an RTM_NEWLINK request can trigger a NULL pointer dereference. Reject devices without ieee802154_ptr along with devices of the wrong type. Fixes: 51e0e5d ("ieee802154: 6lowpan: remove multiple lowpan per wpan support") Cc: stable@vger.kernel.org Reported-by: Vega Signed-off-by: Zhiling Zou Link: https://lore.kernel.org/0b715da69bd15a86ddc47dad5cf12da648211050.1787997209.git.zhilinz@nebusec.ai Signed-off-by: Stefan Schmidt Signed-off-by: Greg Kroah-Hartman Changed files: net/ieee802154/6lowpan/core.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=1c7710af7ad9532b534f1c134c11b04dbe4e0e0f ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-97601 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-97601 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: Not available 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: 1 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).