{"id":"CVE-2026-90108","summary":"net/smc: free stashed qentry before overwrite in REQ_ADD_LINK to ADD_LINK transition","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: free stashed qentry before overwrite in REQ_ADD_LINK to ADD_LINK transition\n\nWhen smc_llc_event_handler() transitions the local LLC flow from\nSMC_LLC_FLOW_REQ_ADD_LINK to SMC_LLC_FLOW_ADD_LINK on arrival of an ADD_LINK\nrequest, it calls smc_llc_flow_qentry_set() unconditionally:\n\n\tif (lgr-\u003ellc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK) {\n\t\tlgr-\u003ellc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;\n\t\tsmc_llc_flow_qentry_set(&lgr-\u003ellc_flow_lcl, qentry);\n\t\t...\n\t}\n\nA CONFIRM_LINK or ADD_LINK_CONT arriving while flow-\u003etype is\nSMC_LLC_FLOW_REQ_ADD_LINK is stashed into flow-\u003eqentry via the\nSMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT handler (which stores into\nflow-\u003eqentry for any non-NONE flow type).  When the subsequent ADD_LINK\narrives, the REQ_ADD_LINK branch overwrites flow-\u003eqentry with the new pointer\nwithout first freeing the stashed allocation, leaking one kmalloc object.\n\nThe stashed entry has no consumer: smc_llc_wait() is only called from\nllc_add_link_work, which is not yet scheduled while the flow type remains\nREQ_ADD_LINK.  No waiter is sleeping on llc_msg_waiter at this point.\nIt is safe to unconditionally free any stashed qentry before\nthe overwrite.\n\nCall smc_llc_flow_qentry_del() before smc_llc_flow_qentry_set() in the\nREQ_ADD_LINK branch.  smc_llc_flow_qentry_del() already checks flow-\u003eqentry\nbefore freeing, so the normal path where no entry is stashed is a no-op.","modified":"2026-09-18T03:48:35.564161728Z","published":"2026-09-17T16:06:16.813Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90108.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/036322025d6e440cb75fc6fecbba9a16b271a2ae"},{"type":"WEB","url":"https://git.kernel.org/stable/c/056395acb7041b3a1f2baa08d89a1938a8b8776a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0fb9a513766071ea9d5f3bf988e39241b8e9ee3b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7dd55348c0d9399a9448847819e9f3904ae507ad"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b08aacfb226a840628151643b6a34eecf545d311"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e25a602c45c76a7130878db72bcf6f76df04bf85"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90108.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90108"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b4ba4652b3f8b7c9bbb5786f8acf4724bdab2196"},{"fixed":"7dd55348c0d9399a9448847819e9f3904ae507ad"},{"fixed":"056395acb7041b3a1f2baa08d89a1938a8b8776a"},{"fixed":"b08aacfb226a840628151643b6a34eecf545d311"},{"fixed":"0fb9a513766071ea9d5f3bf988e39241b8e9ee3b"},{"fixed":"e25a602c45c76a7130878db72bcf6f76df04bf85"},{"fixed":"036322025d6e440cb75fc6fecbba9a16b271a2ae"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90108.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90108.json"}}],"schema_version":"1.9.0"}