{"id":"CVE-2026-64523","revision":"67c4325ad4154d328550ad8510734591","records":[{"revision":"67c4325ad4154d328550ad8510734591","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-64523","aliases":[],"title":"net/handshake: Take a long-lived file reference at submit","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/handshake: Take a long-lived file reference at submit\n\nhandshake_nl_accept_doit() needs the file pointer backing\nreq->hr_sk->sk_socket to survive the window between\nhandshake_req_next() and the subsequent FD_PREPARE() and get_file().\nThe submit-side sock_hold() does not provide that.  sk_refcnt keeps\nstruct sock alive, but struct socket is owned by sock->file: when\nthe consumer fputs the last file reference, sock_release() tears\nthe socket down regardless of any sock_hold.\n\nAdd an hr_file pointer to struct handshake_req and acquire an\nexplicit reference on sock->file during handshake_req_submit().\nhandshake_complete() and handshake_req_cancel() release the\nreference on the completion-bit-winning path.\n\nThe submit error path must also release the file reference, but\nafter rhashtable insertion a concurrent handshake_req_cancel() can\ndiscover the request and race the error path.  Gate the error-path\ncleanup -- sk_destruct restoration, fput, and request destruction\n-- with test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED), the same\nserialization handshake_complete() and handshake_req_cancel()\nalready use.  When cancel has already claimed ownership, the submit\nerror path returns without touching the request; socket teardown\nhandles final destruction.\n\nThe accept-side dereferences are not yet retargeted; that change\ncomes in the next patch.","state":0,"publishedAt":"2026-07-25T09:20:47.606+00:00","modifiedAt":"2026-10-21T12:43:25.473+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/handshake/handshake.h\",\n                        \"net/handshake/netlink.c\",\n                        \"net/handshake/request.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3b3009ea8abb713b022d94fba95ec270cf6e7eae\",\n                            \"lessThan\": \"22e371a93563c30ebebc576db049785e0d7fc617\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b3009ea8abb713b022d94fba95ec270cf6e7eae\",\n                            \"lessThan\": \"685b10dd0e32c7782cead16c8cf055c609678583\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b3009ea8abb713b022d94fba95ec270cf6e7eae\",\n                            \"lessThan\": \"b913801ad9b9a51437d84d030ec6843e08976bd6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b3009ea8abb713b022d94fba95ec270cf6e7eae\",\n                            \"lessThan\": \"16eaba5aa89c04eea125905bb8f988c1897f4f29\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b3009ea8abb713b022d94fba95ec270cf6e7eae\",\n                            \"lessThan\": \"09dba37eee70d0596e26645015f1aa95a9848e9d\",\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/handshake/handshake.h\",\n                        \"net/handshake/netlink.c\",\n                        \"net/handshake/request.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.4\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.4\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.160\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.93\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.44\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.12\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/22e371a93563c30ebebc576db049785e0d7fc617","https://git.kernel.org/stable/c/685b10dd0e32c7782cead16c8cf055c609678583","https://git.kernel.org/stable/c/b913801ad9b9a51437d84d030ec6843e08976bd6","https://git.kernel.org/stable/c/16eaba5aa89c04eea125905bb8f988c1897f4f29","https://git.kernel.org/stable/c/09dba37eee70d0596e26645015f1aa95a9848e9d"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64523","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-64523","identifiers":["CVE-2026-64523"]},"retained":false,"historicalAffected":[]}],"coverage":[]}