{"id":"CVE-2026-43031","state":"PUBLISHED","title":"net: xilinx: axienet: Fix BQL accounting for multi-BD TX packets","description":"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.","publishedAt":"2026-05-01T14:15:31.256Z","updatedAt":"2026-08-05T12:25:24.979Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c900e49d58eb32b192b6d200ace4ae3ab89779d4","status":"affected","lessThan":"2a0323a913109b52bfc9f5ea7b92a1b249e07d3e","versionType":"git"},{"version":"c900e49d58eb32b192b6d200ace4ae3ab89779d4","status":"affected","lessThan":"3c3a6b9020c01fde7b22e8550105de0b59904f61","versionType":"git"},{"version":"c900e49d58eb32b192b6d200ace4ae3ab89779d4","status":"affected","lessThan":"d1978d03e86785872871bff9c2623174b10740de","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/xilinx/xilinx_axienet_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/xilinx/xilinx_axienet_main.c"]}],"references":["https://git.kernel.org/stable/c/2a0323a913109b52bfc9f5ea7b92a1b249e07d3e","https://git.kernel.org/stable/c/3c3a6b9020c01fde7b22e8550105de0b59904f61","https://git.kernel.org/stable/c/d1978d03e86785872871bff9c2623174b10740de"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43031.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43031","state":"PUBLISHED","datePublished":"2026-05-01T14:15:31.256Z","dateUpdated":"2026-08-05T12:25:24.979Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.977Z"},"containers":{"cna":{"title":"net: xilinx: axienet: Fix BQL accounting for multi-BD TX packets","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c900e49d58eb32b192b6d200ace4ae3ab89779d4","status":"affected","lessThan":"2a0323a913109b52bfc9f5ea7b92a1b249e07d3e","versionType":"git"},{"version":"c900e49d58eb32b192b6d200ace4ae3ab89779d4","status":"affected","lessThan":"3c3a6b9020c01fde7b22e8550105de0b59904f61","versionType":"git"},{"version":"c900e49d58eb32b192b6d200ace4ae3ab89779d4","status":"affected","lessThan":"d1978d03e86785872871bff9c2623174b10740de","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/xilinx/xilinx_axienet_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/xilinx/xilinx_axienet_main.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2a0323a913109b52bfc9f5ea7b92a1b249e07d3e"},{"url":"https://git.kernel.org/stable/c/3c3a6b9020c01fde7b22e8550105de0b59904f61"},{"url":"https://git.kernel.org/stable/c/d1978d03e86785872871bff9c2623174b10740de"}],"metrics":[{"cvssV3_1":{"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"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable cleanup runs on transmitted packets for a network interface; in a reasonable embedded/router/server deployment, an unauthenticated remote peer can cause multi-fragment replies or forwarded traffic to be transmitted through the affected axienet device.\nAC:L - The trigger is repeated multi-BD scatter-gather TX completion with descriptors split across NAPI polls, which can be induced through sustained traffic and does not require winning an attacker-uncontrolled race.\nPR:N - No local privileges are needed in the network-triggered scenario because packets from a remote peer can cause the host or forwarding device to transmit through the affected interface.\nUI:N - Once the affected interface is up and carrying traffic, exploitation does not require any user action by a victim.\nS:U - The impact remains within the kernel/network device availability scope and does not cross a virtualization, sandbox, or separate security authority boundary.\nC:N - The bug is an accounting mismatch in BQL byte completion reporting; it does not expose memory contents or create a read primitive.\nI:N - The vulnerable path does not corrupt memory or attacker-controlled data; it under-credits completed TX bytes and affects queue state only.\nA:H - Repeated under-accounting makes BQL believe bytes remain permanently in flight, eventually stalling the TX queue and causing a persistent denial of transmit service on the affected network interface."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:25:24.979Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}