{"cve":"CVE-2021-46999","nvd":{"published":"2024-02-28T09:15:38.130","modified":"2026-08-04T10:16:40.750","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: do asoc update earlier in sctp_sf_do_dupcook_a\n\nThere's a panic that occurs in a few of envs, the call trace is as below:\n\n  [] general protection fault, ... 0x29acd70f1000a: 0000 [#1] SMP PTI\n  [] RIP: 0010:sctp_ulpevent_notify_peer_addr_change+0x4b/0x1fa [sctp]\n  []  sctp_assoc_control_transport+0x1b9/0x210 [sctp]\n  []  sctp_do_8_2_transport_strike.isra.16+0x15c/0x220 [sctp]\n  []  sctp_cmd_interpreter.isra.21+0x1231/0x1a10 [sctp]\n  []  sctp_do_sm+0xc3/0x2a0 [sctp]\n  []  sctp_generate_timeout_event+0x81/0xf0 [sctp]\n\nThis is caused by a transport use-after-free issue. When processing a\nduplicate COOKIE-ECHO chunk in sctp_sf_do_dupcook_a(), both COOKIE-ACK\nand SHUTDOWN chunks are allocated with the transort from the new asoc.\nHowever, later in the sideeffect machine, the old asoc is used to send\nthem out and old asoc's shutdown_last_sent_to is set to the transport\nthat SHUTDOWN chunk attached to in sctp_cmd_setup_t2(), which actually\nbelongs to the new asoc. After the new_asoc is freed and the old asoc\nT2 timeout, the old asoc's shutdown_last_sent_to that is already freed\nwould be accessed in sctp_sf_t2_timer_expire().\n\nThanks Alexander and Jere for helping dig into this issue.\n\nTo fix it, this patch is to do the asoc update first, then allocate\nthe COOKIE-ACK and SHUTDOWN chunks with the 'updated' old asoc. This\nwould make more sense, as a chunk from an asoc shouldn't be sent out\nwith another asoc. We had fixed quite a few issues caused by this.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/0bfd913c2121b3d553bfd52810fe6061d542d625","https://git.kernel.org/stable/c/35b4f24415c854cd718ccdf38dbea6297f010aae","https://git.kernel.org/stable/c/61b877bad9bb0d82b7d8841be50872557090a704","https://git.kernel.org/stable/c/b1b31948c0af44628e43353828453461bb74098f","https://git.kernel.org/stable/c/d624f2991b977821375fbd56c91b0c91d456a697"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2021-46999","score":0.00743,"percentile":0.54719,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}