{"id":"CVE-2026-72330","state":"PUBLISHED","title":"net/tls: Consume empty data records in tls_sw_read_sock()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Consume empty data records in tls_sw_read_sock()\n\nA peer may send a zero-length TLS application_data record; TLS 1.3\nexplicitly permits these as a traffic-analysis countermeasure (RFC\n8446, Section 5.1). After decryption such a record has full_len ==\n0. tls_sw_read_sock() hands it to the read_actor, which has no\npayload to consume and returns zero. The loop treats a zero return\nas backpressure (used <= 0), requeues the skb at the head of\nrx_list, and stops. rx_list is serviced head-first on the next\ncall, so the empty record is dequeued, fails the same way, and is\nrequeued again; every later record on the connection is blocked\nbehind it.\n\ntls_sw_recvmsg() does not stall on this: a zero-length data record\ncopies nothing and falls through to consume_skb(). Mirror that in\nthe read_sock() path by recognizing an empty data record before\nthe actor runs, consuming it, and continuing.","publishedAt":"2026-08-15T05:55:40.555Z","updatedAt":"2026-10-16T18:55:18.242Z","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":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"0867b0f2513ebc1c475af9898c97f4772a68d964","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"c6b440cf766a557b08d25f1b571b3d57d039686e","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"e8a4c9fc437b16aef38f86ce3275677e36924259","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"ebc295ce343600c2d60c1e1e0c5d192080217457","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"3be28e2c9cd0230cb51fd4967df095273afd3848","versionType":"git"}],"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":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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/0867b0f2513ebc1c475af9898c97f4772a68d964","https://git.kernel.org/stable/c/c6b440cf766a557b08d25f1b571b3d57d039686e","https://git.kernel.org/stable/c/e8a4c9fc437b16aef38f86ce3275677e36924259","https://git.kernel.org/stable/c/ebc295ce343600c2d60c1e1e0c5d192080217457","https://git.kernel.org/stable/c/3be28e2c9cd0230cb51fd4967df095273afd3848"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72330.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72330","state":"PUBLISHED","datePublished":"2026-08-15T05:55:40.555Z","dateUpdated":"2026-10-16T18:55:18.242Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.919Z"},"containers":{"cna":{"title":"net/tls: Consume empty data records in tls_sw_read_sock()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Consume empty data records in tls_sw_read_sock()\n\nA peer may send a zero-length TLS application_data record; TLS 1.3\nexplicitly permits these as a traffic-analysis countermeasure (RFC\n8446, Section 5.1). After decryption such a record has full_len ==\n0. tls_sw_read_sock() hands it to the read_actor, which has no\npayload to consume and returns zero. The loop treats a zero return\nas backpressure (used <= 0), requeues the skb at the head of\nrx_list, and stops. rx_list is serviced head-first on the next\ncall, so the empty record is dequeued, fails the same way, and is\nrequeued again; every later record on the connection is blocked\nbehind it.\n\ntls_sw_recvmsg() does not stall on this: a zero-length data record\ncopies nothing and falls through to consume_skb(). Mirror that in\nthe read_sock() path by recognizing an empty data record before\nthe actor runs, consuming it, and continuing."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"0867b0f2513ebc1c475af9898c97f4772a68d964","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"c6b440cf766a557b08d25f1b571b3d57d039686e","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"e8a4c9fc437b16aef38f86ce3275677e36924259","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"ebc295ce343600c2d60c1e1e0c5d192080217457","versionType":"git"},{"version":"662fbcec32f4af6bdcf5b4006b792ebe9543d945","status":"affected","lessThan":"3be28e2c9cd0230cb51fd4967df095273afd3848","versionType":"git"}],"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":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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/0867b0f2513ebc1c475af9898c97f4772a68d964"},{"url":"https://git.kernel.org/stable/c/c6b440cf766a557b08d25f1b571b3d57d039686e"},{"url":"https://git.kernel.org/stable/c/e8a4c9fc437b16aef38f86ce3275677e36924259"},{"url":"https://git.kernel.org/stable/c/ebc295ce343600c2d60c1e1e0c5d192080217457"},{"url":"https://git.kernel.org/stable/c/3be28e2c9cd0230cb51fd4967df095273afd3848"}],"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 - A remote TLS peer sends zero-length TLS 1.3 application_data records over TCP; they are decrypted in the kTLS software RX path and processed in tls_sw_read_sock(), reachable from network-facing consumers such as NVMe-over-TCP host I/O via sock->ops->read_sock.\nAC:L - After a normal TLS handshake, sending a standards-compliant zero-length application_data record reliably reproduces the stall; no races, special memory layout, or rare timing are required.\nPR:N - Exploitation requires only being the remote TLS peer on an established kTLS connection (e.g. a malicious NVMe-oF target); no local account, capability, namespace, or administrator privileges on the victim host are needed.\nUI:N - No victim user action beyond the system maintaining its normal encrypted network connection; the attacker triggers the flaw by sending protocol-valid TLS records.\nS:U - Impact is confined to stalling the affected TLS/kTLS connection and its dependent service I/O; it does not cross a security boundary such as guest-to-host escape or sandbox breakout.\nC:N - The flaw is a receive-path logic error that requeues an empty skb indefinitely; there is no out-of-bounds access, use-after-free, or other memory corruption that could disclose kernel or application data.\nI:N - The bug does not modify kernel memory, credentials, or application data; it only prevents forward progress on the stalled connection by blocking consumption of subsequent decrypted records.\nA:H - The empty record is permanently requeued at the head of rx_list, creating a repeatable deadlock that blocks all later traffic on the connection and can hang NVMe-over-TCP (or similar read_sock) I/O until the connection is torn down."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:42:52.302Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72330","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T18:47:08.220194Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:18.242Z"}}]}}}