{"id":"CVE-2026-64541","revision":"800a62ff718a4c9eb51c859b68a44a72","records":[{"revision":"800a62ff718a4c9eb51c859b68a44a72","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-64541","aliases":[],"title":"net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket\n\nsmc_cdc_rx_handler() looks up the connection by token under the link\ngroup's conns_lock, drops the lock, and then dereferences conn and the\nsmc_sock derived from it, ending in sock_hold(&smc->sk) inside\nsmc_cdc_msg_recv(). No reference is held across the lock release.\n\nThe only reference pinning the socket while the connection is\ndiscoverable in the link group is taken in smc_lgr_register_conn()\n(sock_hold) and dropped in __smc_lgr_unregister_conn() (sock_put), both\nunder conns_lock. Once the handler drops conns_lock, a concurrent\nclose() -> smc_release() -> smc_conn_free() -> smc_lgr_unregister_conn()\ncan drop that reference and free the smc_sock, so the handler's later\nsock_hold() runs on freed memory:\n\n  WARNING: lib/refcount.c:25 at refcount_warn_saturate\n  Workqueue: rxe_wq do_work\n   refcount_warn_saturate (lib/refcount.c:25)\n   smc_cdc_msg_recv (net/smc/smc_cdc.c:430)\n   smc_cdc_rx_handler (net/smc/smc_cdc.c:502)\n   smc_wr_rx_tasklet_fn (net/smc/smc_wr.c:445)\n   tasklet_action_common (kernel/softirq.c:938)\n   handle_softirqs (kernel/softirq.c:622)\n  Kernel panic - not syncing: panic_on_warn set\n\nOnly SMC-R is affected. The SMC-D receive tasklet is stopped by\ntasklet_kill(&conn->rx_tsklet) in smc_conn_free() before the connection\nis unregistered, so it cannot run concurrently with the free.\n\nTake the socket reference while still holding conns_lock, so the\nregistration reference can no longer be the last one, and drop it once\nthe handler is done.","state":0,"publishedAt":"2026-07-27T20:10:34.439+00:00","modifiedAt":"2026-10-19T20:48:39.587+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/smc/smc_cdc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"8de4f665d0febfb92803dece377791a563fc7041\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"8145b432136285e01091815b48ceb2dae261f262\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"1951bffbc6493ec34cff3956b29d4bc6606904a6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"647b19e5cc145a2f1f685ae8ff3805a17356888c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"472e9d7c0d5b03be3ff91ff941f57da822b031bc\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"ce5aa8084329351086894aa34d77e40301d5bd3d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d7b0e37c1ac152905b18a5b9506179091a35b0b6\",\n                            \"lessThan\": \"9d160b35cc34a2ba8229d07651468a7848325135\",\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/smc/smc_cdc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.18\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.18\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\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/8de4f665d0febfb92803dece377791a563fc7041","https://git.kernel.org/stable/c/8145b432136285e01091815b48ceb2dae261f262","https://git.kernel.org/stable/c/1951bffbc6493ec34cff3956b29d4bc6606904a6","https://git.kernel.org/stable/c/647b19e5cc145a2f1f685ae8ff3805a17356888c","https://git.kernel.org/stable/c/472e9d7c0d5b03be3ff91ff941f57da822b031bc","https://git.kernel.org/stable/c/3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb","https://git.kernel.org/stable/c/ce5aa8084329351086894aa34d77e40301d5bd3d","https://git.kernel.org/stable/c/9d160b35cc34a2ba8229d07651468a7848325135"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64541","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-64541","identifiers":["CVE-2026-64541"]},"retained":false,"historicalAffected":[]}],"coverage":[]}