{"id":"CVE-2026-98123","revision":"f657739a41674b6a9f10f8e26274d0d3","records":[{"revision":"f657739a41674b6a9f10f8e26274d0d3","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98123","aliases":[],"title":"sctp: fix soft lockup from unpadded ASCONF-ACK parameter iteration","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix soft lockup from unpadded ASCONF-ACK parameter iteration\n\nsctp_verify_asconf() walks ASCONF-ACK parameters with\nsctp_walk_params(), which advances by SCTP_PAD4(length), while the\nconsumer sctp_get_asconf_response() iterates the same parameters\nadvancing by the raw length, without padding. A single odd-length\nparameter desynchronises the two walks and makes the consumer\ninterpret attacker-controlled bytes at a misaligned offset.\n\nWhen those bytes yield a length of zero, the while loop over\nasconf_ack_len makes no progress, spinning forever in softirq\ncontext, and the watchdog reports a soft lockup. All reads stay\nwithin the received skb, so the lockup is a pure remote denial of\nservice. A remote peer can trigger it with a crafted ASCONF-ACK on\nan ADD-IP enabled association with an outstanding ASCONF (RFC 5061\nsection 4.1.2 requires the chunk to be authenticated, but the\npredefined empty key id 0 allows the peer to compute the same\nassociation HMAC from publicly exchanged parameters, so the gate\ndoes not help).\n\nThe SCTP_PARAM_ERR_CAUSE case of sctp_verify_asconf() also performs\nno length check, letting a parameter without a complete error\nheader reach the consumer, which reads errhdr.cause past the end of\nthe parameter, an out-of-bounds read.\n\nReject SCTP_PARAM_ERR_CAUSE parameters shorter than\nsizeof(struct sctp_addip_param) + sizeof(struct sctp_errhdr) at the\nverifier, and advance the consumer iterator with the same padding\nrule as the verifier to keep the two walks in lockstep. The verifier\nchange guarantees a complete error header in every ERR_CAUSE\nparameter the consumer can see, so the consumer's asconf_ack_len\ncheck is dropped and it returns err_param->cause directly. The\nconsumer padding fix is still required because odd lengths remain\nvalid for SCTP_PARAM_ERR_CAUSE per RFC 5061.\n\nThe issue was found by ZeroHive, a vulnerability hunting agent at\nTencent Yunding Lab.","state":0,"publishedAt":"2026-09-25T10:36:05.993+00:00","modifiedAt":"2026-10-19T09:14:15.281+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/sctp/sm_make_chunk.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"ba54cad229977f4fae6355dbdaf117088414fdd0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"7d8e7ab6a0665888beee91f7ad77ac805963c4fd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"5fbc6a778d5fce7628821236972596acb18e1065\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"4548d843e7b29f6d150d8caae4e64015fa226b0c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"abf59d7f6fff23227256e8199aca5ade45758f8b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"3be02999ab9131a4b96eb1eda4ca48b1cea80f03\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"7ba84e2971d208a2d6413a334ec28a8a32cdce0f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\n                            \"lessThan\": \"2cb0b0b1ed69430bf73740377ea0a1c44c50db63\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/sctp/sm_make_chunk.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.12\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.12\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.271\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.222\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.111\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.53\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.7\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/ba54cad229977f4fae6355dbdaf117088414fdd0","https://git.kernel.org/stable/c/7d8e7ab6a0665888beee91f7ad77ac805963c4fd","https://git.kernel.org/stable/c/5fbc6a778d5fce7628821236972596acb18e1065","https://git.kernel.org/stable/c/4548d843e7b29f6d150d8caae4e64015fa226b0c","https://git.kernel.org/stable/c/abf59d7f6fff23227256e8199aca5ade45758f8b","https://git.kernel.org/stable/c/3be02999ab9131a4b96eb1eda4ca48b1cea80f03","https://git.kernel.org/stable/c/7ba84e2971d208a2d6413a334ec28a8a32cdce0f","https://git.kernel.org/stable/c/2cb0b0b1ed69430bf73740377ea0a1c44c50db63"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98123","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98123","identifiers":["CVE-2026-98123"]},"retained":false,"historicalAffected":[]}],"coverage":[]}