{"id":"CVE-2026-89477","revision":"bde29fa3945242b0b2a505a20ee39acd","records":[{"revision":"bde29fa3945242b0b2a505a20ee39acd","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89477","aliases":[],"title":"sctp: fix NULL deref on untransmitted RECONF completion","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix NULL deref on untransmitted RECONF completion\n\nsctp_process_strreset_outreq(), sctp_process_strreset_addstrm_out() and\nsctp_process_strreset_resp() complete a pending stream reconfiguration\nrequest by stopping the reconf timer on the transport it was sent on:\n\n\tt = asoc->strreset_chunk->transport;\n\tif (timer_delete(&t->reconf_timer))\n\t\tsctp_transport_put(t);\n\nchunk->transport is assigned by __sctp_packet_append_chunk() when the\nchunk is appended to an outbound packet, and sctp_outq_flush_ctrl() arms\nthe reconf timer at that same point. A request already published in\nasoc->strreset_chunk but not yet transmitted has neither, so completing\nit dereferences NULL.\n\nTwo ways to get there. sctp_send_asconf_del_ip() sets\nasoc->src_out_of_asoc_ok without sending anything when the address being\nremoved is the association's last one, and sctp_outq_flush_ctrl() then\nleaves every non-ASCONF control chunk queued; as only\nsctp_process_asconf_ack() clears that flag, it persists. An unprivileged\nprocess that removes such an address and then asks for a stream reset\npanics the kernel from softirq. A peer needs neither ASCONF nor local\nhelp: sctp_cmd_interpreter() uncorks the outqueue only once the whole\npacket has been processed, so a reply built while walking a RECONF chunk\nstays untransmitted for the rest of that walk, and one RECONF chunk\ncarrying [Incoming SSN Reset Request, Outgoing SSN Reset Request,\nResponse] -- or two RECONF chunks in one packet -- reaches the same\ndereference.\n\n KASAN: null-ptr-deref in range [0x00000000000001e8-0x00000000000001ef]\n RIP: 0010:timer_delete+0x67/0x110\n Call Trace:\n \n sctp_process_strreset_addstrm_out (net/sctp/stream.c:832)\n sctp_sf_do_reconf (net/sctp/sm_statefuns.c:4212)\n sctp_do_sm (net/sctp/sm_sideeffect.c:1172)\n sctp_assoc_bh_rcv (net/sctp/associola.c:1044)\n sctp_rcv (net/sctp/input.c:243)\n ip_local_deliver (net/ipv4/ip_input.c:262)\n process_backlog (net/core/dev.c:6680)\n \n\nA response can only acknowledge a request that was actually sent, so do\nnot match asoc->strreset_chunk while chunk->transport is NULL. Guarding\nthe lookup covers all three completion sites.","state":0,"publishedAt":"2026-09-11T19:43:33.851+00:00","modifiedAt":"2026-10-19T08:47:26.175+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/stream.c\"\n ],\n \"versions\": [\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"79ff751311e80fa0370007e46a79a6d601685e75\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"53141db979687eae7dc6d29414cefc77034f967e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"68891125af5a5dfbca728809a16637a869bbe0df\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"b2d6d873b4dfb5b84194061c4b40a1cd85b92ca4\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"77ea60f2d24002c308f224db44a4542c466489af\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"25419f516ea84b1e7d3d55aae5215ac86ece0c66\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"0ee697defc0594f1da810ed75d9d643fb46f5318\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"81054476453640159149cb6704e834893e16736b\",\n \"lessThan\": \"2db9bfa3e27bdea15e05ea70b56bad3d21e570ec\",\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/stream.c\"\n ],\n \"versions\": [\n {\n \"version\": \"4.11\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"4.11\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.270\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.221\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.188\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.157\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.109\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.50\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.4\",\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":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/79ff751311e80fa0370007e46a79a6d601685e75","https://git.kernel.org/stable/c/53141db979687eae7dc6d29414cefc77034f967e","https://git.kernel.org/stable/c/68891125af5a5dfbca728809a16637a869bbe0df","https://git.kernel.org/stable/c/b2d6d873b4dfb5b84194061c4b40a1cd85b92ca4","https://git.kernel.org/stable/c/77ea60f2d24002c308f224db44a4542c466489af","https://git.kernel.org/stable/c/25419f516ea84b1e7d3d55aae5215ac86ece0c66","https://git.kernel.org/stable/c/0ee697defc0594f1da810ed75d9d643fb46f5318","https://git.kernel.org/stable/c/2db9bfa3e27bdea15e05ea70b56bad3d21e570ec"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89477","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89477","identifiers":["CVE-2026-89477"]},"retained":false,"historicalAffected":[]}],"coverage":[]}