{"id":"DEBIAN-CVE-2023-53296","details":"In the Linux kernel, the following vulnerability has been resolved:  sctp: check send stream number after wait_for_sndbuf  This patch fixes a corner case where the asoc out stream count may change after wait_for_sndbuf.  When the main thread in the client starts a connection, if its out stream count is set to N while the in stream count in the server is set to N - 2, another thread in the client keeps sending the msgs with stream number N - 1, and waits for sndbuf before processing INIT_ACK.  However, after processing INIT_ACK, the out stream count in the client is shrunk to N - 2, the same to the in stream count in the server. The crash occurs when the thread waiting for sndbuf is awake and sends the msg in a non-existing stream(N - 1), the call trace is as below:    KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]   Call Trace:    \u003cTASK\u003e    sctp_cmd_send_msg net/sctp/sm_sideeffect.c:1114 [inline]    sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1777 [inline]    sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline]    sctp_do_sm+0x197d/0x5310 net/sctp/sm_sideeffect.c:1170    sctp_primitive_SEND+0x9f/0xc0 net/sctp/primitive.c:163    sctp_sendmsg_to_asoc+0x10eb/0x1a30 net/sctp/socket.c:1868    sctp_sendmsg+0x8d4/0x1d90 net/sctp/socket.c:2026    inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:825    sock_sendmsg_nosec net/socket.c:722 [inline]    sock_sendmsg+0xde/0x190 net/socket.c:745  The fix is to add an unlikely check for the send stream number after the thread wakes up from the wait_for_sndbuf.","modified":"2026-09-15T09:03:02.589957344Z","published":"2025-09-16T08:15:38.937Z","upstream":["CVE-2023-53296"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-53296"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.25-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53296.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.25-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53296.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.25-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-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"}]}