{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-23142", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-01-11T14:28:41.512Z", "datePublished": "2025-05-01T12:55:32.614Z", "dateUpdated": "2026-08-05T11:57:01.863Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:57:01.863Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: detect and prevent references to a freed transport in sendmsg\n\nsctp_sendmsg() re-uses associations and transports when possible by\ndoing a lookup based on the socket endpoint and the message destination\naddress, and then sctp_sendmsg_to_asoc() sets the selected transport in\nall the message chunks to be sent.\n\nThere's a possible race condition if another thread triggers the removal\nof that selected transport, for instance, by explicitly unbinding an\naddress with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have\nbeen set up and before the message is sent. This can happen if the send\nbuffer is full, during the period when the sender thread temporarily\nreleases the socket lock in sctp_wait_for_sndbuf().\n\nThis causes the access to the transport data in\nsctp_outq_select_transport(), when the association outqueue is flushed,\nto result in a use-after-free read.\n\nThis change avoids this scenario by having sctp_transport_free() signal\nthe freeing of the transport, tagging it as \"dead\". In order to do this,\nthe patch restores the \"dead\" bit in struct sctp_transport, which was\nremoved in\ncommit 47faa1e4c50e (\"sctp: remove the dead field of sctp_transport\").\n\nThen, in the scenario where the sender thread has released the socket\nlock in sctp_wait_for_sndbuf(), the bit is checked again after\nre-acquiring the socket lock to detect the deletion. This is done while\nholding a reference to the transport to prevent it from being freed in\nthe process.\n\nIf the transport was deleted while the socket lock was relinquished,\nsctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the\nsend.\n\nThe bug was found by a private syzbot instance (see the error report [1]\nand the C reproducer that triggers it [2])." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The reproduced trigger is a pair of local syscalls on the attacker's own SCTP socket — a blocking sendmsg() parked in sctp_wait_for_sndbuf() plus a concurrent setsockopt(SCTP_SOCKOPT_BINDX_REM) that frees the selected transport. No remote peer input is required to drive the bug; this matches the repo's scoring of the structurally identical sctp_wait_for_connect() lock-drop UAF (CVE-2026-63971).\nAC:L - The attacker controls both sides of the race and does not need to win a tight window: shrinking SO_SNDBUF forces the sender to sleep in sctp_wait_for_sndbuf() with the socket lock released, and the second thread can issue BINDX_REM at any point during that arbitrarily long sleep, making the use-after-free essentially deterministic.\nPR:L - Creating an SCTP socket and calling sctp_bindx()/SCTP_ASCONF_SUPPORTED requires no capability — the only ns_capable() checks in net/sctp/socket.c are CAP_NET_BIND_SERVICE for privileged ports, which the attacker avoids by binding a high port. Any unprivileged local user with the sctp module available can run the published reproducer.\nUI:N - The attacking process performs every step itself within its own threads; no victim action, configuration change, or interaction with another user is needed.\nS:U - The corruption is confined to kernel slab memory within the same security authority; there is no VM, IOMMU, or sandbox boundary crossed.\nC:H - This is a slab use-after-free on a kzalloc'd sctp_transport with a long, attacker-controlled reallocation window, and the freed object's asoc/dst/packet pointers are dereferenced — allowing a sprayed replacement object to be used to read arbitrary kernel memory, well beyond the bounded KASAN read that was reported.\nI:H - The freed transport is not merely read: sctp_outq_select_transport() performs list_add_tail() into the freed object's send_ready field, and sctp_packet_config()/sctp_transport_burst_limited() write vtag, max_size, size, overhead, cwnd and burst_limited into it, yielding controlled writes into a reallocated slab object suitable for control-flow hijacking.\nA:H - The bug was found as a KASAN slab-use-after-free with a reproducer, and dereferencing a freed transport's asoc/dst pointers or corrupting the send_ready list readily produces a kernel oops or panic, which an unprivileged user can trigger repeatedly." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/sctp/structs.h", "net/sctp/socket.c", "net/sctp/transport.c" ], "versions": [ { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "547762250220325d350d0917a7231480e0f4142b", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "3257386be6a7eb8a8bfc9cbfb746df4eb4fc70e8", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "0f7df4899299ce4662e5f95badb9dbc57cc37fa5", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "7a63f4fb0efb4e69efd990cbb740a848679ec4b0", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "c6fefcb71d246baaf3bacdad1af7ff50ebcfe652", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "9e7c37fadb3be1fc33073fcf10aa96d166caa697", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "5bc83bdf5f5b8010d1ca5a4555537e62413ab4e2", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "2e5068b7e0ae0a54f6cfd03a2f80977da657f1ee", "status": "affected", "versionType": "git" }, { "version": "df132eff463873e14e019a07f387b4d577d6d1f9", "lessThan": "f1a69a940de58b16e8249dff26f74c8cc59b32be", "status": "affected", "versionType": "git" }, { "version": "26e51e5287eed4d96ea66a3da95429f42940f013", "status": "affected", "versionType": "git" }, { "version": "8b97e045bd6d37f96f161e4d371ae174148e1587", "status": "affected", "versionType": "git" }, { "version": "e044554e97e812eb257d073bcc130e0ea653858f", "status": "affected", "versionType": "git" }, { "version": "8376fdc999be008f0e9918db52f1ed8c08f5a1c9", "status": "affected", "versionType": "git" }, { "version": "cd947138e8c31e8cfcd489c12e9b97271beb6e79", "status": "affected", "versionType": "git" }, { "version": "3.18.128", "lessThan": "3.19", "status": "affected", "versionType": "semver" }, { "version": "4.4.166", "lessThan": "4.5", "status": "affected", "versionType": "semver" }, { "version": "4.9.142", "lessThan": "4.10", "status": "affected", "versionType": "semver" }, { "version": "4.14.85", "lessThan": "4.15", "status": "affected", "versionType": "semver" }, { "version": "4.19.6", "lessThan": "4.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/sctp/structs.h", "net/sctp/socket.c", "net/sctp/transport.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.293", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.237", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.181", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.135", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.88", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.24", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.12", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.3", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.4.293" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.10.237" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.15.181" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.1.135" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.6.88" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.24" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.13.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.14.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.15" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.166" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.85" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.6" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/547762250220325d350d0917a7231480e0f4142b" }, { "url": "https://git.kernel.org/stable/c/3257386be6a7eb8a8bfc9cbfb746df4eb4fc70e8" }, { "url": "https://git.kernel.org/stable/c/0f7df4899299ce4662e5f95badb9dbc57cc37fa5" }, { "url": "https://git.kernel.org/stable/c/7a63f4fb0efb4e69efd990cbb740a848679ec4b0" }, { "url": "https://git.kernel.org/stable/c/c6fefcb71d246baaf3bacdad1af7ff50ebcfe652" }, { "url": "https://git.kernel.org/stable/c/9e7c37fadb3be1fc33073fcf10aa96d166caa697" }, { "url": "https://git.kernel.org/stable/c/5bc83bdf5f5b8010d1ca5a4555537e62413ab4e2" }, { "url": "https://git.kernel.org/stable/c/2e5068b7e0ae0a54f6cfd03a2f80977da657f1ee" }, { "url": "https://git.kernel.org/stable/c/f1a69a940de58b16e8249dff26f74c8cc59b32be" } ], "title": "sctp: detect and prevent references to a freed transport in sendmsg", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:42:29.798Z" } } ] } }