{"id":"CVE-2026-64047","title":"net: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring","summary":"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 p…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 73963a375885d5ccb7def39fd0b4f542e0f343dd","Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 47110c3a9ac247b688657337f5981efcfcb240dc","Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 84158c2997159df4a0d70cd9c46774512d32a522","Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 131ef12057d92b77b636321b7849c69222405a97","Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 66339b71f105e6f83e0da3b9583d95077534fe1d","Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < eca989eab4b2599dcb02f72140a7c08f08838520","Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 2fb0dc7e0099686c4e9d2732745d8a31b18c3628","Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 285943c6e7ca309bbea84b253745154241d9788a","Linux d529d6c9f7e3aaeac13c4948f79799ccb825f29d","Linux >= 5.4.14 < 5.5","Linux 5.5"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:35:54.546412Z"},"published":"2026-07-19","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:20.839Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64047","references":[{"url":"https://git.kernel.org/stable/c/73963a375885d5ccb7def39fd0b4f542e0f343dd"},{"url":"https://git.kernel.org/stable/c/47110c3a9ac247b688657337f5981efcfcb240dc"},{"url":"https://git.kernel.org/stable/c/84158c2997159df4a0d70cd9c46774512d32a522"},{"url":"https://git.kernel.org/stable/c/131ef12057d92b77b636321b7849c69222405a97"},{"url":"https://git.kernel.org/stable/c/66339b71f105e6f83e0da3b9583d95077534fe1d"},{"url":"https://git.kernel.org/stable/c/eca989eab4b2599dcb02f72140a7c08f08838520"},{"url":"https://git.kernel.org/stable/c/2fb0dc7e0099686c4e9d2732745d8a31b18c3628"},{"url":"https://git.kernel.org/stable/c/285943c6e7ca309bbea84b253745154241d9788a"}],"tags":["cve.org"],"epss":0.00514,"epssPercentile":0.4249,"ingestedAt":"2026-10-16T17:24:46.792Z","slug":"CVE-2026-64047","body":"## Overview\n\nIn 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).\n\n## Affected\n\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 73963a375885d5ccb7def39fd0b4f542e0f343dd`\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 47110c3a9ac247b688657337f5981efcfcb240dc`\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 84158c2997159df4a0d70cd9c46774512d32a522`\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 131ef12057d92b77b636321b7849c69222405a97`\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 66339b71f105e6f83e0da3b9583d95077534fe1d`\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < eca989eab4b2599dcb02f72140a7c08f08838520`\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 2fb0dc7e0099686c4e9d2732745d8a31b18c3628`\n- `Linux >= 9aaaa56845a06aeabdd597cbe19492dc01f281ec < 285943c6e7ca309bbea84b253745154241d9788a`\n- `Linux d529d6c9f7e3aaeac13c4948f79799ccb825f29d`\n- `Linux >= 5.4.14 < 5.5`\n- `Linux 5.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}