{"id":"CVE-2026-80864","title":"RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp","summary":"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 stat…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 0136b528b753c5a56e4d997ef20b86bb6750b8fb","Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < ffa4f0be69656be1755090f02db38d49816585c6","Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < d4cd32eb8bd2b0ffbdc7b1f3d82ce6a371f8f844","Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 60dfd47929cd1e7070daa810d40ce538d888410d","Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 6f7014237405e7f032b5c53a82d9eccf6161c291","Linux 4.8"],"published":"2026-09-04","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:44:58.452Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80864","references":[{"url":"https://git.kernel.org/stable/c/0136b528b753c5a56e4d997ef20b86bb6750b8fb"},{"url":"https://git.kernel.org/stable/c/ffa4f0be69656be1755090f02db38d49816585c6"},{"url":"https://git.kernel.org/stable/c/d4cd32eb8bd2b0ffbdc7b1f3d82ce6a371f8f844"},{"url":"https://git.kernel.org/stable/c/60dfd47929cd1e7070daa810d40ce538d888410d"},{"url":"https://git.kernel.org/stable/c/6f7014237405e7f032b5c53a82d9eccf6161c291"}],"tags":["cve.org"],"epss":0.00156,"epssPercentile":0.04354,"ingestedAt":"2026-10-19T09:16:01.491Z","slug":"CVE-2026-80864","body":"## Overview\n\nIn 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->resp.resources[] while\nrxe_prepare_res()/find_resource() walk it; free_rd_atomic_resources()\nalso leaves the cached pointer qp->resp.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->resp.resources on the ENOMEM path. Also clear\nqp->resp.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.\n\n## Affected\n\n- `Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 0136b528b753c5a56e4d997ef20b86bb6750b8fb`\n- `Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < ffa4f0be69656be1755090f02db38d49816585c6`\n- `Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < d4cd32eb8bd2b0ffbdc7b1f3d82ce6a371f8f844`\n- `Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 60dfd47929cd1e7070daa810d40ce538d888410d`\n- `Linux >= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 6f7014237405e7f032b5c53a82d9eccf6161c291`\n- `Linux 4.8`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}