{"id":"CVE-2026-80995","revision":"ccae4733bb2e4fe98f117a214f480daf","records":[{"revision":"ccae4733bb2e4fe98f117a214f480daf","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80995","aliases":[],"title":"net: mctp: hold a reference to the route device in mctp_route_lookup()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mctp: hold a reference to the route device in mctp_route_lookup()\n\nmctp_route_lookup() uses rt->dev without holding a reference on it.\nmctp_route_lookup_single() returns the route under RCU only, so the\nroute's device can be torn down concurrently: mctp_dev_put() drops the\nlast reference and synchronously kfree()s mdev->addrs.  mctp_dev_saddr()\nthen reads rt->dev->addrs[0], giving a use-after-free reachable by an\nunprivileged local AF_MCTP user on the receive/forwarding path (no\nCAP_NET_RAW required):\n\n  BUG: KASAN: slab-use-after-free in mctp_route_lookup\n  Read of size 1 at addr ... by task mctp_uaf/...\n   mctp_route_lookup\n   mctp_pkttype_receive\n  Freed by task ...:\n   kfree\n   mctp_dev_put\n   mctp_dev_notify\n\nIn the same window mctp_dst_from_route() -> mctp_dev_hold() also\nincrements a refcount that has already reached zero\n(\"refcount_t: addition on 0 ... mctp_dev_hold\").\n\nThis reintroduces the use-after-free class of CVE-2023-3439: the source\naddress lookup was moved ahead of the point where the destination takes\nits device reference.\n\nTake a reference with refcount_inc_not_zero() before touching rt->dev,\nskip a device that is already dead, and drop the reference once the\ndestination has taken its own.","state":0,"publishedAt":"2026-09-11T19:42:50.866+00:00","modifiedAt":"2026-10-19T08:46:19.571+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/mctp/route.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1\",\n                            \"lessThan\": \"cc561f8af25586300c2f9d285babb163b866b293\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1\",\n                            \"lessThan\": \"408da1df18116c971c3392e21e50586688cd3fbf\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/mctp/route.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7.1\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"7.1\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 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,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/cc561f8af25586300c2f9d285babb163b866b293","https://git.kernel.org/stable/c/408da1df18116c971c3392e21e50586688cd3fbf"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80995","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80995","identifiers":["CVE-2026-80995"]},"retained":false,"historicalAffected":[]}],"coverage":[]}