{"id":"CVE-2021-47591","state":"PUBLISHED","title":"mptcp: remove tcp ulp setsockopt support","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: remove tcp ulp setsockopt support\n\nTCP_ULP setsockopt cannot be used for mptcp because its already\nused internally to plumb subflow (tcp) sockets to the mptcp layer.\n\nsyzbot managed to trigger a crash for mptcp connections that are\nin fallback mode:\n\nKASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]\nCPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0\nRIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline]\n[..]\n __tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline]\n tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160\n do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391\n mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638\n\nRemove support for TCP_ULP setsockopt.","publishedAt":"2024-06-19T14:53:54.918Z","updatedAt":"2026-05-11T13:57:30.264Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d9e4c129181004ec94b315b0c9db5eeb09da75e6","status":"affected","lessThan":"3de0c86d42f841d1d64f316cd949e65c566f0734","versionType":"git"},{"version":"d9e4c129181004ec94b315b0c9db5eeb09da75e6","status":"affected","lessThan":"404cd9a22150f24acf23a8df2ad0c094ba379f57","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/sockopt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.11","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/sockopt.c"]}],"references":["https://git.kernel.org/stable/c/3de0c86d42f841d1d64f316cd949e65c566f0734","https://git.kernel.org/stable/c/404cd9a22150f24acf23a8df2ad0c094ba379f57"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47591.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47591","state":"PUBLISHED","datePublished":"2024-06-19T14:53:54.918Z","dateUpdated":"2026-05-11T13:57:30.264Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-24T15:11:00.733Z"},"containers":{"cna":{"title":"mptcp: remove tcp ulp setsockopt support","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: remove tcp ulp setsockopt support\n\nTCP_ULP setsockopt cannot be used for mptcp because its already\nused internally to plumb subflow (tcp) sockets to the mptcp layer.\n\nsyzbot managed to trigger a crash for mptcp connections that are\nin fallback mode:\n\nKASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]\nCPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0\nRIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline]\n[..]\n __tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline]\n tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160\n do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391\n mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638\n\nRemove support for TCP_ULP setsockopt."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d9e4c129181004ec94b315b0c9db5eeb09da75e6","status":"affected","lessThan":"3de0c86d42f841d1d64f316cd949e65c566f0734","versionType":"git"},{"version":"d9e4c129181004ec94b315b0c9db5eeb09da75e6","status":"affected","lessThan":"404cd9a22150f24acf23a8df2ad0c094ba379f57","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/sockopt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.11","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/sockopt.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3de0c86d42f841d1d64f316cd949e65c566f0734"},{"url":"https://git.kernel.org/stable/c/404cd9a22150f24acf23a8df2ad0c094ba379f57"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T13:57:30.264Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/3de0c86d42f841d1d64f316cd949e65c566f0734","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/404cd9a22150f24acf23a8df2ad0c094ba379f57","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:39:59.892Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47591","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T17:12:33.600657Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-11T17:34:52.347Z"}}]}}}