{"id":"CVE-2026-23125","revision":"917f9fe96aa04d82ad9d062ea627609c","records":[{"revision":"917f9fe96aa04d82ad9d062ea627609c","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-23125","aliases":[],"title":"sctp: move SCTP_CMD_ASSOC_SHKEY right after SCTP_CMD_PEER_INIT","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: move SCTP_CMD_ASSOC_SHKEY right after SCTP_CMD_PEER_INIT\n\nA null-ptr-deref was reported in the SCTP transmit path when SCTP-AUTH key\ninitialization fails:\n\n ==================================================================\n KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]\n CPU: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G W 6.6.0 #2\n RIP: 0010:sctp_packet_bundle_auth net/sctp/output.c:264 [inline]\n RIP: 0010:sctp_packet_append_chunk+0xb36/0x1260 net/sctp/output.c:401\n Call Trace:\n\n sctp_packet_transmit_chunk+0x31/0x250 net/sctp/output.c:189\n sctp_outq_flush_data+0xa29/0x26d0 net/sctp/outqueue.c:1111\n sctp_outq_flush+0xc80/0x1240 net/sctp/outqueue.c:1217\n sctp_cmd_interpreter.isra.0+0x19a5/0x62c0 net/sctp/sm_sideeffect.c:1787\n sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]\n sctp_do_sm+0x1a3/0x670 net/sctp/sm_sideeffect.c:1169\n sctp_assoc_bh_rcv+0x33e/0x640 net/sctp/associola.c:1052\n sctp_inq_push+0x1dd/0x280 net/sctp/inqueue.c:88\n sctp_rcv+0x11ae/0x3100 net/sctp/input.c:243\n sctp6_rcv+0x3d/0x60 net/sctp/ipv6.c:1127\n\nThe issue is triggered when sctp_auth_asoc_init_active_key() fails in\nsctp_sf_do_5_1C_ack() while processing an INIT_ACK. In this case, the\ncommand sequence is currently:\n\n- SCTP_CMD_PEER_INIT\n- SCTP_CMD_TIMER_STOP (T1_INIT)\n- SCTP_CMD_TIMER_START (T1_COOKIE)\n- SCTP_CMD_NEW_STATE (COOKIE_ECHOED)\n- SCTP_CMD_ASSOC_SHKEY\n- SCTP_CMD_GEN_COOKIE_ECHO\n\nIf SCTP_CMD_ASSOC_SHKEY fails, asoc->shkey remains NULL, while\nasoc->peer.auth_capable and asoc->peer.peer_chunks have already been set by\nSCTP_CMD_PEER_INIT. This allows a DATA chunk with auth = 1 and shkey = NULL\nto be queued by sctp_datamsg_from_user().\n\nSince command interpretation stops on failure, no COOKIE_ECHO should been\nsent via SCTP_CMD_GEN_COOKIE_ECHO. However, the T1_COOKIE timer has already\nbeen started, and it may enqueue a COOKIE_ECHO into the outqueue later. As\na result, the DATA chunk can be transmitted together with the COOKIE_ECHO\nin sctp_outq_flush_data(), leading to the observed issue.\n\nSimilar to the other places where it calls sctp_auth_asoc_init_active_key()\nright after sctp_process_init(), this patch moves the SCTP_CMD_ASSOC_SHKEY\nimmediately after SCTP_CMD_PEER_INIT, before stopping T1_INIT and starting\nT1_COOKIE. This ensures that if shared key generation fails, authenticated\nDATA cannot be sent. It also allows the T1_INIT timer to retransmit INIT,\ngiving the client another chance to process INIT_ACK and retry key setup.","state":0,"publishedAt":"2026-02-14T15:09:54.756+00:00","modifiedAt":"2026-10-19T18:25:32.393+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_statefuns.c\"\n ],\n \"versions\": [\n {\n \"version\": \"730fc3d05cd4ba4c9ce2de91f3d43349e95dbbf5\",\n \"lessThan\": \"5a309bedf02ee08b0653215f06c94d61ec7a214a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"730fc3d05cd4ba4c9ce2de91f3d43349e95dbbf5\",\n \"lessThan\": \"784428ab1889eb185a1459e9d6bc52df33d572ef\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"730fc3d05cd4ba4c9ce2de91f3d43349e95dbbf5\",\n \"lessThan\": \"e94294798548e8cfbd80869e1d2f97efce92582c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"730fc3d05cd4ba4c9ce2de91f3d43349e95dbbf5\",\n \"lessThan\": \"e7e81abbcc5620c9532080538f9709a6ea382855\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"730fc3d05cd4ba4c9ce2de91f3d43349e95dbbf5\",\n \"lessThan\": \"bf2b543b3cc4ebb4ab5bca4f8dfa5612035d45b8\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"730fc3d05cd4ba4c9ce2de91f3d43349e95dbbf5\",\n \"lessThan\": \"0c4adb1f391a7b92a0405e9d7c05624c0d9f8a65\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"730fc3d05cd4ba4c9ce2de91f3d43349e95dbbf5\",\n \"lessThan\": \"a80c9d945aef55b23b54838334345f20251dad83\",\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_statefuns.c\"\n ],\n \"versions\": [\n {\n \"version\": \"2.6.24\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"2.6.24\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.249\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.199\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.162\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.122\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.68\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.8\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.19\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/5a309bedf02ee08b0653215f06c94d61ec7a214a","https://git.kernel.org/stable/c/784428ab1889eb185a1459e9d6bc52df33d572ef","https://git.kernel.org/stable/c/e94294798548e8cfbd80869e1d2f97efce92582c","https://git.kernel.org/stable/c/e7e81abbcc5620c9532080538f9709a6ea382855","https://git.kernel.org/stable/c/bf2b543b3cc4ebb4ab5bca4f8dfa5612035d45b8","https://git.kernel.org/stable/c/0c4adb1f391a7b92a0405e9d7c05624c0d9f8a65","https://git.kernel.org/stable/c/a80c9d945aef55b23b54838334345f20251dad83"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23125","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-23125","identifiers":["CVE-2026-23125"]},"retained":false,"historicalAffected":[]}],"coverage":[]}