{"id":"CVE-2023-52986","title":"bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener\n\nA listening socket linked to a sockmap has its sk_prot overridden. It\npoints to one of the struct …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < 9bd6074e1872d22190a8da30e796cbf937d334f0","Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < c681d7a4ed3d360de0574f4d6b7305a8de8dc54f","Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < 12b0ec7c6953e1602957926439e5297095d7d065","Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < ddce1e091757d0259107c6c0c7262df201de2b66","Linux 5.7"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T20:14:08.337990Z"},"published":"2025-03-27","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:20:53.473Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2023-52986","references":[{"url":"https://git.kernel.org/stable/c/9bd6074e1872d22190a8da30e796cbf937d334f0"},{"url":"https://git.kernel.org/stable/c/c681d7a4ed3d360de0574f4d6b7305a8de8dc54f"},{"url":"https://git.kernel.org/stable/c/12b0ec7c6953e1602957926439e5297095d7d065"},{"url":"https://git.kernel.org/stable/c/ddce1e091757d0259107c6c0c7262df201de2b66"}],"tags":["cve.org"],"epss":0.00281,"epssPercentile":0.20701,"ingestedAt":"2026-11-05T22:38:31.751Z","slug":"CVE-2023-52986","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener\n\nA listening socket linked to a sockmap has its sk_prot overridden. It\npoints to one of the struct proto variants in tcp_bpf_prots. The variant\ndepends on the socket's family and which sockmap programs are attached.\n\nA child socket cloned from a TCP listener initially inherits their sk_prot.\nBut before cloning is finished, we restore the child's proto to the\nlistener's original non-tcp_bpf_prots one. This happens in\ntcp_create_openreq_child -> tcp_bpf_clone.\n\nToday, in tcp_bpf_clone we detect if the child's proto should be restored\nby checking only for the TCP_BPF_BASE proto variant. This is not\ncorrect. The sk_prot of listening socket linked to a sockmap can point to\nto any variant in tcp_bpf_prots.\n\nIf the listeners sk_prot happens to be not the TCP_BPF_BASE variant, then\nthe child socket unintentionally is left if the inherited sk_prot by\ntcp_bpf_clone.\n\nThis leads to issues like infinite recursion on close [1], because the\nchild state is otherwise not set up for use with tcp_bpf_prot operations.\n\nAdjust the check in tcp_bpf_clone to detect all of tcp_bpf_prots variants.\n\nNote that it wouldn't be sufficient to check the socket state when\noverriding the sk_prot in tcp_bpf_update_proto in order to always use the\nTCP_BPF_BASE variant for listening sockets. Since commit\nb8b8315e39ff (\"bpf, sockmap: Remove unhash handler for BPF sockmap usage\")\nit is possible for a socket to transition to TCP_LISTEN state while already\nlinked to a sockmap, e.g. connect() -> insert into map ->\nconnect(AF_UNSPEC) -> listen().\n\n[1]: https://lore.kernel.org/all/00000000000073b14905ef2e7401@google.com/\n\n## Affected\n\n- `Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < 9bd6074e1872d22190a8da30e796cbf937d334f0`\n- `Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < c681d7a4ed3d360de0574f4d6b7305a8de8dc54f`\n- `Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < 12b0ec7c6953e1602957926439e5297095d7d065`\n- `Linux >= e80251555f0befd1271e74b080bccf0ff0348bfc < ddce1e091757d0259107c6c0c7262df201de2b66`\n- `Linux 5.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}