From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-72037][LOW] net: lan743x: Initialize eth_syslock spinlock before use commit 39139b1c1c2b614096519b526112c726adb12ff0 upstream. Date: Sun, 16 Aug 2026 06:03:50 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-72037 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: 0 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: dfaefd9a7808736fcd2ed0de108f55c4badc15cc List-Id: CVE: CVE-2026-72037 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: net: lan743x: Initialize eth_syslock spinlock before use commit 39139b1c1c2b614096519b526112c726adb12ff0 upstream. Commit: dfaefd9a7808736fcd2ed0de108f55c4badc15cc Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dfaefd9a7808736fcd2ed0de108f55c4badc15cc Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72037 Analysis date: Sun, 16 Aug 2026 06:03:50 -0400 ActionableScore: 0 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: lan743x may acquire adapter eth_syslock_spinlock before initialization during PCI11X1X probe, which can trigger a debug spinlock warning and possible local availability impact on affected debug kernels. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-72037 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72037 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-2026-72037 LOW 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:H/UI:N/S:U/C:N/I:N/A:H';CWE-665;CWE-667;CWE-703;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.4';DESCR 'lan743x can use adapter eth_syslock_spinlock before it is initialized during the PCI11x1x probe path. With CONFIG_DEBUG_SPINLOCK enabled, this can trigger a spinlock debug check warning and may lead to a denial of service if the system treats such warnings as fatal. For the CVSS the PR:H is used because reliable triggering normally requires administrative control over driver probe, module loading, device bind or reset operations. The issue is not network reachable and is not triggered by normal packet traffic. Impact is availability only. For the paranoid score, this remains DoS only because the patch context shows improper lock initialization rather than UAF, OOB access, or another memory corruption primitive.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 0) SKIP CVE-2026-72037 UNKNOWN SKIP The Fixes patch not applied yet, so unlikely that actual: 46b777ad9a8c269113634cee6a380bc4e53f3964 YES NO NO unknown MAYBE REMOTE INIT NETWORK HARDWARE DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 0 * Final recommended bucket: **Ordinary Moderate / Low-like** ## 2. Signal breakdown Triggered positive signals: * Availability impact realistic: +1. The issue can cause a debug spinlock warning and potentially a fatal failure if the system uses CONFIG_DEBUG_SPINLOCK together with panic-on-warning style policy. * Reliable kernel crash / strong DoS: +0. The commit describes a debug check trip, not a normal-production reliable crash path. Triggered negative signals: * Requires admin/root/CAP_* in typical deployments: -2. Reliable triggering normally requires driver probe control, module load/unload, device bind/unbind, reset, or boot/probe sequencing. * Physical-only or rare hardware-only condition: -2. The issue is specific to Microchip LAN743x / PCI11X1X hardware and the relevant probe path. * Legacy / non-default execution mode: -1. The described failure depends on CONFIG_DEBUG_SPINLOCK, which is a debug-oriented kernel configuration and not typical production behavior. Not triggered: * Remote reachable / network-triggerable: +0. Normal packet traffic does not reach this bug. * Local unprivileged trigger: +0. No unprivileged local interface is shown. * Generic memory corruption: +0. The patch only reorders spin_lock_init before first use. * Real lifetime corruption: +0. No UAF, double-free, stale pointer, RCU lifetime issue, or refcount misuse is shown. * Privilege escalation plausible: +0. No exploit primitive is supported by the patch context. * Confidentiality / Integrity impact: +0. No disclosure or write primitive is indicated. ## 3. Reachability analysis The bug is reached during the PCI11X1X probe sequence in lan743x_hardware_init(). A practical attacker would normally need administrative control over driver/device lifecycle operations, or physical/control-plane influence over the affected device environment. Namespaces and containers do not materially lower the privilege requirement unless device management is explicitly delegated, which is uncommon for this hardware probe path. The path is not network reachable and is not triggered by receiving Ethernet frames. Exposure also depends on affected hardware and debug spinlock configuration. Call-site confidence: high, because the provided patch shows the relevant call order directly. ## 4. Severity interpretation This behaves like a Low or ordinary Moderate reliability issue, not an actionable Moderate and not an Important-class vulnerability. The theoretical impact is availability-only under debug or fatal-warning configurations. The realistic exploitation evidence does not show memory corruption, privilege escalation, sensitive data exposure, or a remotely reachable path. ## 5. One-sentence report phrase lan743x may acquire adapter eth_syslock_spinlock before initialization during PCI11X1X probe, which can trigger a debug spinlock warning and possible local availability impact on affected debug kernels. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED The patch is a straightforward initialization-order fix in a device-specific probe path, with no supported memory corruption or security-boundary bypass primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: net: lan743x: Initialize eth_syslock spinlock before use commit 39139b1c1c2b614096519b526112c726adb12ff0 upstream. Commit: dfaefd9a7808736fcd2ed0de108f55c4badc15cc Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dfaefd9a7808736fcd2ed0de108f55c4badc15cc Commit description: lan743x_hardware_init() calls pci11x1x_strap_get_status() during the PCI11x1x probe sequence. That helper acquires the Ethernet subsystem hardware lock via lan743x_hs_syslock_acquire(), which relies on adapter->eth_syslock_spinlock to serialize access. The spinlock is currently initialized only after the strap status is read. With CONFIG_DEBUG_SPINLOCK enabled, taking the zeroed initialized spinlock can trip the spinlock debug check. Fix by initializing adapter->eth_syslock_spinlock before reading the strap status so the probe path never attempts to lock an uninitialized spinlock. Fixes: 46b777ad9a8c ("net: lan743x: Add support to SGMII 1G and 2.5G") Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Andrea Righi Reviewed-by: David Thompson Reviewed-by: Thangaraj Samynathan Link: https://patch.msgid.link/20260626163218.3591486-1-arighi@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman Diffstat -rw-r--r-- drivers/net/ethernet/microchip/lan743x_main.c 2 Changed files: drivers/net/ethernet/microchip/lan743x_main.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=dfaefd9a7808736fcd2ed0de108f55c4badc15cc ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-72037 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72037 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:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.4 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: 0 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).