{"cve":"CVE-2026-64047","nvd":{"published":"2026-07-19T16:17:45.053","modified":"2026-10-19T21:17:21.780","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring\n\nWhen an sk_msg scatterlist ring wraps (sg.end < sg.start),\ntls_push_record() chains the tail portion of the ring to the head\nusing sg_chain(). An extra entry in the sg array is reserved for\nthis:\n\n  struct sk_msg_sg {\n        [...]\n        /* The extra two elements:\n         * 1) used for chaining the front and sections when the list becomes\n         *    partitioned (e.g. end < start). The crypto APIs require the\n         *    chaining;\n         * 2) to chain tailer SG entries after the message.\n         */\n        struct scatterlist              data[MAX_MSG_FRAGS + 2];\n\nThe current code uses MAX_SKB_FRAGS + 1 as the ring size:\n\n    sg_chain(&msg_pl->sg.data[msg_pl->sg.start],\n             MAX_SKB_FRAGS - msg_pl->sg.start + 1,\n             msg_pl->sg.data);\n\nThis places the chain pointer at\n\n  sg_chain(data[start], (MAX_SKB_FRAGS - msg_start + 1) .. =\n  &data[start] + (MAX_SKB_FRAGS - msg_start + 1) - 1 =\n  data[start + (MAX_SKB_FRAGS - start + 1) - 1] =\n  data[MAX_SKB_FRAGS]\n\ninstead of the true last entry. This is likely due to a \"race\" of\nthe commit under Fixes landing close to\ncommit 031097d9e079 (\"bpf: sk_msg, zap ingress queue on psock down\")\n\nConvert to ARRAY_SIZE and drop the data[start] / - start (as suggested\nby Sabrina).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-193","CWE-191"],"references":["https://git.kernel.org/stable/c/131ef12057d92b77b636321b7849c69222405a97","https://git.kernel.org/stable/c/285943c6e7ca309bbea84b253745154241d9788a","https://git.kernel.org/stable/c/2fb0dc7e0099686c4e9d2732745d8a31b18c3628","https://git.kernel.org/stable/c/47110c3a9ac247b688657337f5981efcfcb240dc","https://git.kernel.org/stable/c/66339b71f105e6f83e0da3b9583d95077534fe1d"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-64047","score":0.00514,"percentile":0.4352,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}