CVE-2026-43031

/* * PoC Concept for CVE-2026-43031 * This vulnerability is a logic bug in the Linux kernel driver. * It requires specific hardware (Xilinx Axi Ethernet) to trigger. * * Triggering condition: * 1. Generate network traffic that requires multiple Buffer Descriptors (BDs). * 2. Ensure the completion of these BDs spans across different NAPI poll cycles. * 3. This causes the BQL (Byte Queue Limits) accounting to underflow/stall. * * The following is a pseudo-code representation of the traffic generation logic. */ void generate_trigger_traffic() { // Configure interface for Jumbo Frames or Scatter-Gather I/O // Send packets larger than the standard BD size // Rate limit to interact with NAPI polling timing while (1) { send_large_packet(target_ip, packet_size > BD_MAX_SIZE); // Introduce slight delay to allow NAPI interaction usleep(100); } // Result: The TX queue on the target device will eventually stop sending packets. }

{"cve": {"id": "CVE-2026-43031", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:47.680", "lastModified": "2026-05-08T18:38:07.040", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: xilinx: axienet: Fix BQL accounting for multi-BD TX packets\n\nWhen a TX packet spans multiple buffer descriptors (scatter-gather),\naxienet_free_tx_chain sums the per-BD actual length from descriptor\nstatus into a caller-provided accumulator. That sum is reset on each\nNAPI poll. If the BDs for a single packet complete across different\npolls, the earlier bytes are lost and never credited to BQL. This\ncauses BQL to think bytes are permanently in-flight, eventually\nstalling the TX queue.\n\nThe SKB pointer is stored only on the last BD of a packet. When that\nBD completes, use skb->len for the byte count instead of summing\nper-BD status lengths. This matches netdev_sent_queue(), which debits\nskb->len, and naturally survives across polls because no partial\npacket contributes to the accumulator."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "6.18.22", "matchCriteriaId": "A0B69104-1744-49F9-BFD7-533364994A3E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.12", "matchCriteriaId": "0A2B9540-02D5-41B4-B16A-82AF66FD4F36"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2a0323a913109b52bfc9f5ea7b92a1b249e07d3e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3c3a6b9020c01fde7b22e8550105de0b59904f61", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d1978d03e86785872871bff9c2623174b10740de", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}