{"id":"CVE-2026-80864","summary":"RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp\n\nrxe_qp_from_attr() handles IB_QP_MAX_DEST_RD_ATOMIC outside the\nIB_QP_STATE path, so it holds no state_lock and runs while the responder\ntask rxe_receiver() (recv_task on rxe_wq) is live. A modify_qp() setting\nonly that attribute calls free_rd_atomic_resources() then\nalloc_rd_atomic_resources(), swapping qp-\u003eresp.resources[] while\nrxe_prepare_res()/find_resource() walk it; free_rd_atomic_resources()\nalso leaves the cached pointer qp-\u003eresp.res dangling. A local\nunprivileged user can race the free/realloc into a use-after-free in\nrxe_receiver() (local DoS).\n\nDrain recv_task around the swap with rxe_disable_task()/rxe_enable_task(),\nas rxe_qp_reset() already does when tearing this array down, re-enabling\nonly after alloc_rd_atomic_resources() succeeds so the responder never\nresumes against a NULL qp-\u003eresp.resources on the ENOMEM path. Also clear\nqp-\u003eresp.res in free_rd_atomic_resources(), like the rxe_resp.c\ncompletion paths.\n\nReproduced under KASAN; the slab-use-after-free in rxe_receiver() is gone.","modified":"2026-09-06T03:46:54.655482773Z","published":"2026-09-04T15:55:18.791Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80864.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0136b528b753c5a56e4d997ef20b86bb6750b8fb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/60dfd47929cd1e7070daa810d40ce538d888410d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6f7014237405e7f032b5c53a82d9eccf6161c291"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d4cd32eb8bd2b0ffbdc7b1f3d82ce6a371f8f844"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ffa4f0be69656be1755090f02db38d49816585c6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80864.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80864"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8700e3e7c4857d28ebaa824509934556da0b3e76"},{"fixed":"0136b528b753c5a56e4d997ef20b86bb6750b8fb"},{"fixed":"ffa4f0be69656be1755090f02db38d49816585c6"},{"fixed":"d4cd32eb8bd2b0ffbdc7b1f3d82ce6a371f8f844"},{"fixed":"60dfd47929cd1e7070daa810d40ce538d888410d"},{"fixed":"6f7014237405e7f032b5c53a82d9eccf6161c291"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80864.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.8.0"},{"fixed":"6.12.108"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.49"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.13"}]},{"type":"ECOSYSTEM","events":[{"introduced":"7.2.0"},{"fixed":"7.2.3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80864.json"}}],"schema_version":"1.9.0"}