{"id":"CVE-2026-64047","state":"PUBLISHED","title":"net: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring","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).","publishedAt":"2026-07-19T15:39:31.960Z","updatedAt":"2026-10-19T20:28:10.717Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"73963a375885d5ccb7def39fd0b4f542e0f343dd","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"47110c3a9ac247b688657337f5981efcfcb240dc","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"84158c2997159df4a0d70cd9c46774512d32a522","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"131ef12057d92b77b636321b7849c69222405a97","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"66339b71f105e6f83e0da3b9583d95077534fe1d","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"eca989eab4b2599dcb02f72140a7c08f08838520","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"2fb0dc7e0099686c4e9d2732745d8a31b18c3628","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"285943c6e7ca309bbea84b253745154241d9788a","versionType":"git"},{"version":"d529d6c9f7e3aaeac13c4948f79799ccb825f29d","status":"affected","versionType":"git"},{"version":"5.4.14","status":"affected","lessThan":"5.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/tls/tls_sw.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/tls/tls_sw.c"]}],"references":["https://git.kernel.org/stable/c/73963a375885d5ccb7def39fd0b4f542e0f343dd","https://git.kernel.org/stable/c/47110c3a9ac247b688657337f5981efcfcb240dc","https://git.kernel.org/stable/c/84158c2997159df4a0d70cd9c46774512d32a522","https://git.kernel.org/stable/c/131ef12057d92b77b636321b7849c69222405a97","https://git.kernel.org/stable/c/66339b71f105e6f83e0da3b9583d95077534fe1d","https://git.kernel.org/stable/c/eca989eab4b2599dcb02f72140a7c08f08838520","https://git.kernel.org/stable/c/2fb0dc7e0099686c4e9d2732745d8a31b18c3628","https://git.kernel.org/stable/c/285943c6e7ca309bbea84b253745154241d9788a"],"weaknesses":["CWE-191"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64047.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64047","state":"PUBLISHED","datePublished":"2026-07-19T15:39:31.960Z","dateUpdated":"2026-10-19T20:28:10.717Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.029Z"},"containers":{"cna":{"title":"net: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring","descriptions":[{"lang":"en","value":"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)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"73963a375885d5ccb7def39fd0b4f542e0f343dd","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"47110c3a9ac247b688657337f5981efcfcb240dc","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"84158c2997159df4a0d70cd9c46774512d32a522","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"131ef12057d92b77b636321b7849c69222405a97","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"66339b71f105e6f83e0da3b9583d95077534fe1d","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"eca989eab4b2599dcb02f72140a7c08f08838520","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"2fb0dc7e0099686c4e9d2732745d8a31b18c3628","versionType":"git"},{"version":"9aaaa56845a06aeabdd597cbe19492dc01f281ec","status":"affected","lessThan":"285943c6e7ca309bbea84b253745154241d9788a","versionType":"git"},{"version":"d529d6c9f7e3aaeac13c4948f79799ccb825f29d","status":"affected","versionType":"git"},{"version":"5.4.14","status":"affected","lessThan":"5.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/tls/tls_sw.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/tls/tls_sw.c"]}],"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"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The flaw is in kernel TLS (kTLS) software transmit encryption triggered when a TLS socket sends records; remote peers on established TLS connections drive this TX path through normal network I/O.\nAC:L - An attacker who controls connection traffic can reliably create the wrapped sk_msg ring state via BPF sockmap SK_MSG verdict helpers (push/pop/redirect) and then trigger record push on demand.\nPR:N - Exploitation requires no privileges on the target host beyond being a network peer on a kTLS socket with sockmap BPF already configured by the service; attacker capabilities are not needed on the victim system.\nUI:N - Triggering requires only automated server-side TLS transmit activity in response to network input, with no victim user action.\nS:U - Impact is kernel memory corruption and potential privilege escalation within the same kernel/host security boundary, not a cross-VM or sandbox escape by itself.\nC:H - Corrupting an active scatterlist entry causes the AEAD crypto path to follow an incorrect chain, enabling out-of-bounds kernel memory reads beyond intended plaintext buffers.\nI:H - The malformed scatterlist passed to crypto_aead_encrypt() can direct encryption I/O to wrong memory regions, providing an out-of-bounds write primitive exploitable for control-flow hijacking.\nA:H - Scatterlist corruption in the kernel crypto TX path can cause kernel oopses, panics, or fatal BUG conditions when invalid chain entries or page pointers are dereferenced."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:38:39.300Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.14"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64047","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:35:54.546412Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-191","lang":"en","type":"CWE","description":"CWE-191 Integer Underflow (Wrap or Wraparound)"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:28:10.717Z"}}]}}}