{"cve":"CVE-2026-46227","nvd":{"published":"2026-05-28T10:16:38.317","modified":"2026-10-19T20:18:38.597","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL\n\nThe SCTP_SENDALL path in sctp_sendmsg() iterates ep->asocs with\nlist_for_each_entry_safe(), which caches the next entry in @tmp before\nthe loop body runs.  The body calls sctp_sendmsg_to_asoc(), which may\ndrop the socket lock inside sctp_wait_for_sndbuf().\n\nWhile the lock is dropped, another thread can SCTP_SOCKOPT_PEELOFF the\nassociation cached in @tmp, migrating it to a new endpoint via\nsctp_sock_migrate() (list_del_init() + list_add_tail() to\nnewep->asocs), and optionally close the new socket which frees the\nassociation via kfree_rcu().  The cached @tmp can also be freed by a\nnetwork ABORT for that association, processed in softirq while the\nlock is dropped.\n\nsctp_wait_for_sndbuf() revalidates @asoc (the current entry) on re-lock\nvia the \"sk != asoc->base.sk\" and \"asoc->base.dead\" checks, but nothing\nrevalidates @tmp.  After a successful return, the iterator advances to\nthe stale @tmp, yielding either a use-after-free (if the peeled socket\nwas closed) or a list-walk onto the new endpoint's list head (type\nconfusion of &newep->asocs as a struct sctp_association *).\n\nBoth are reachable from CapEff=0; the type-confusion path gives\ncontrolled indirect call via the outqueue.sched->init_sid pointer.\n\nFix by re-deriving @tmp from @asoc after sctp_sendmsg_to_asoc()\nreturns.  @asoc is known to still be on ep->asocs at that point: the\nonly callers that list_del an association from ep->asocs are\nsctp_association_free() (which sets asoc->base.dead) and\nsctp_assoc_migrate() (which changes asoc->base.sk), and\nsctp_wait_for_sndbuf() checks both under the lock before any\nsuccessful return; a tripped check propagates as err < 0 and the loop\nbails before the re-derive.\n\nThe SCTP_ABORT path in sctp_sendmsg_check_sflags() returns 0 and the\nloop hits 'continue' before sctp_sendmsg_to_asoc() is ever called, so\nthe @tmp cached by list_for_each_entry_safe() still covers the\nlock-held free that ba59fb027307 (\"sctp: walk the list of asoc\nsafely\") was added for.","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","CWE-362","CWE-367"],"references":["https://git.kernel.org/stable/c/0c7b55974f97b78d1109025eadf084e74cbf330f","https://git.kernel.org/stable/c/0dbc8cde64280fc37cdd678cced34eaf96cfb197","https://git.kernel.org/stable/c/1bfb06ecb00f7fdf35dba8e8f2877346cbe5e078","https://git.kernel.org/stable/c/6187a172d6ed57d6b2c327836e4407c6456e639d","https://git.kernel.org/stable/c/abb5f36771cc4c05899b34000829a787572a8817"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-46227","score":0.00104,"percentile":0.01006,"date":"2026-10-25"},"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."]}