{"id":"CVE-2023-53296","summary":"sctp: check send stream number after wait_for_sndbuf","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: check send stream number after wait_for_sndbuf\n\nThis patch fixes a corner case where the asoc out stream count may change\nafter wait_for_sndbuf.\n\nWhen the main thread in the client starts a connection, if its out stream\ncount is set to N while the in stream count in the server is set to N - 2,\nanother thread in the client keeps sending the msgs with stream number\nN - 1, and waits for sndbuf before processing INIT_ACK.\n\nHowever, after processing INIT_ACK, the out stream count in the client is\nshrunk to N - 2, the same to the in stream count in the server. The crash\noccurs when the thread waiting for sndbuf is awake and sends the msg in a\nnon-existing stream(N - 1), the call trace is as below:\n\n  KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]\n  Call Trace:\n   \u003cTASK\u003e\n   sctp_cmd_send_msg net/sctp/sm_sideeffect.c:1114 [inline]\n   sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1777 [inline]\n   sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline]\n   sctp_do_sm+0x197d/0x5310 net/sctp/sm_sideeffect.c:1170\n   sctp_primitive_SEND+0x9f/0xc0 net/sctp/primitive.c:163\n   sctp_sendmsg_to_asoc+0x10eb/0x1a30 net/sctp/socket.c:1868\n   sctp_sendmsg+0x8d4/0x1d90 net/sctp/socket.c:2026\n   inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:825\n   sock_sendmsg_nosec net/socket.c:722 [inline]\n   sock_sendmsg+0xde/0x190 net/socket.c:745\n\nThe fix is to add an unlikely check for the send stream number after the\nthread wakes up from the wait_for_sndbuf.","modified":"2026-08-12T03:51:40.097157396Z","published":"2025-09-16T08:11:28.519Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53296.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0443fff49d6352160c200064156c25898bd9f58c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2584024b23552c00d95b50255e47bd18d306d31a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/667eb99cf7c15fe5b0ecefe75cf658e20ef20c9f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9346a1a21142357972a6f466ba6275ddc54b04ac"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a615e7270318fa0b98bf1ff38daf6cf52d840312"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b4b6dfad41aaae9e36e44327b18d5cf4b20dd2ce"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d2128636b303aa9cf065055402ee6697409a8837"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53296.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53296"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5bbbbe32a43199c2b9ea5ea66fab6241c64beb51"},{"fixed":"9346a1a21142357972a6f466ba6275ddc54b04ac"},{"fixed":"0443fff49d6352160c200064156c25898bd9f58c"},{"fixed":"b4b6dfad41aaae9e36e44327b18d5cf4b20dd2ce"},{"fixed":"667eb99cf7c15fe5b0ecefe75cf658e20ef20c9f"},{"fixed":"d2128636b303aa9cf065055402ee6697409a8837"},{"fixed":"a615e7270318fa0b98bf1ff38daf6cf52d840312"},{"fixed":"2584024b23552c00d95b50255e47bd18d306d31a"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53296.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"4.19.281"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.4.241"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.107"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.24"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.2.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53296.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}