From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-53177][LOW] bnxt_en: Fix NULL pointer dereference Date: Mon, 29 Jun 2026 10:41:03 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-53177 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: 0 X-AL-KERNEL-Commit: 964b1c3eb71afe58bb61c8b984164447e000ae8a List-Id: CVE: CVE-2026-53177 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: bnxt_en: Fix NULL pointer dereference Commit: 964b1c3eb71afe58bb61c8b984164447e000ae8a Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=964b1c3eb71afe58bb61c8b984164447e000ae8a Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53177 Analysis date: Mon, 29 Jun 2026 10:41:03 -0400 ActionableScore: 1 ActionableScore lower bound: 0 Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: A NULL pointer dereference in the Broadcom bnxt_en PCIe error recovery path can crash the kernel when recovery runs on an administratively closed NIC, but exploitation requires local or hardware-mediated conditions and does not indicate privilege escalation. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53177 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53177 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-2026-53177 LOW CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';**CWE-476;CWE-754;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'bnxt_en can hit a NULL pointer dereference during PCIe error recovery when the NIC is administratively closed and bp bnapi has already been freed. The error recovery callback can still run for subordinate PCIe devices and may call the IRQ disable and synchronization path that expects bnapi to exist. This can crash the kernel and cause denial of service. For the CVSS the PR:L is used for the paranoid view because a local user or delegated service context might influence NIC state or recovery paths in some environments. Reliable triggering still requires local access and a PCIe error recovery event. The issue is not directly network reachable and remote packets are not expected to trigger this PCIe recovery path by themselves. Impact is denial of service only because the patch indicates a NULL dereference and not a UAF, OOB access, information leak, or privilege escalation primitive.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1) SKIP CVE-2026-53177 SKIP The required patch already applied both for rhel8 and for rhel9: d930276f2cddd0b7294cac7a8fe7b877f6d9e08d YES YES YES unknown MAYBE REMOTE NULLPTR UAF NETWORK HARDWARE LINUS DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 - - guess ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=1 ActionableScoreLower=0 ## 1. ActionableScore * Conservative score: 0 * Paranoid score: 1 * Final recommended bucket: **Ordinary Moderate / Low-like** ## 2. Signal breakdown * Reliable kernel crash / strong DoS: +1. The patch prevents a NULL pointer dereference in `bnxt_disable_int_sync()` during PCIe error recovery on a closed NIC. * Firmware-mediated or hardware-mediated external influence: +1 in paranoid scoring only. PCIe AER or error recovery may be initiated by hardware, firmware, Root Port, or Downstream Port behavior, but this is not normal remote network reachability. * Physical-only or rare hardware/error condition: -1 to -2. Practical triggering requires a specific Broadcom `bnxt_en` device, closed NIC state, and a PCIe error recovery event. * Requires administrative control in typical attacker-driven scenarios: -2 for conservative scoring. A local attacker would usually need CAP_NET_ADMIN or equivalent control to manipulate NIC administrative state, and still may not be able to generate the PCIe error event. * No generic memory corruption signal. The patch indicates NULL dereference, not UAF, OOB write, double-free, refcount abuse, type confusion, or attacker-controlled overwrite. * No LPE signal. There is no demonstrated reclaim, stale object reuse, write primitive, callback corruption, or credential/security-boundary bypass. ## 3. Reachability analysis The bug can occur when PCIe error recovery runs for a `bnxt_en` device whose NIC has been administratively closed and whose `bp->bnapi` state is not allocated. This is not reachable through ordinary packet traffic and should not be treated as remote network-triggerable. In typical deployments, intentionally influencing NIC state requires administrative privileges, while the PCIe error condition itself is hardware or firmware dependent. Containers or namespaces do not materially lower reachability unless they have delegated device or network administration over the physical NIC. ## 4. Severity interpretation This behaves like an ordinary Moderate or Low-like kernel DoS issue, not an Important-class vulnerability. The realistic impact is kernel crash or device recovery failure from a NULL pointer dereference under special PCIe error recovery conditions. Theoretical memory corruption or privilege escalation is not supported by the patch because the fixed condition is a NULL check and there is no evidence of attacker-controlled reuse, overwrite, or sensitive data exposure. ## 5. One-sentence report phrase A NULL pointer dereference in the Broadcom bnxt_en PCIe error recovery path can crash the kernel when recovery runs on an administratively closed NIC, but exploitation requires local or hardware-mediated conditions and does not indicate privilege escalation. ## 6. Manual review recommendation NO MANUAL CHECK NEEDED This can be handled as a low-actionability DoS triage item because the issue is device-specific, not network reachable, requires rare PCIe recovery conditions, and shows no memory corruption or privilege escalation primitive. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: bnxt_en: Fix NULL pointer dereference Commit: 964b1c3eb71afe58bb61c8b984164447e000ae8a Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=964b1c3eb71afe58bb61c8b984164447e000ae8a Commit description: PCIe errors detected by a Root Port or Downstream Port cause error recovery services to run on all subordinate devices regardless of administrative state. The .error_detected() callback, bnxt_io_error_detected(), disables and synchronizes IRQs via bnxt_disable_int_sync(), which calls bnxt_cp_num_to_irq_num() to map completion rings to IRQs using bp->bnapi. Since bp->bnapi is allocated on NIC open and freed on NIC close, PCIe error recovery on a closed NIC can dereference a NULL pointer. Check if bp->bnapi is NULL before disabling and synchronizing IRQs. Fixes: e5811b8 ("bnxt_en: Add IRQ remapping logic.") Cc: stable@vger.kernel.org Signed-off-by: Kyle Meyer Reviewed-by: Pavan Chebbi Link: https://patch.msgid.link/aiNM1CY2-StPilxW@hpe.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman Changed files: drivers/net/ethernet/broadcom/bnxt/bnxt.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=964b1c3eb71afe58bb61c8b984164447e000ae8a ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53177 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53177 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:H/PR:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 4.7 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: 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).