In the Linux kernel, the following vulnerability has been resolved:

RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp

rxe_qp_from_attr() handles IB_QP_MAX_DEST_RD_ATOMIC outside the
IB_QP_STATE path, so it holds no state_lock and runs while the responder
task rxe_receiver() (recv_task on rxe_wq) is live. A modify_qp() setting
only that attribute calls free_rd_atomic_resources() then
alloc_rd_atomic_resources(), swapping qp->resp.resources[] while
rxe_prepare_res()/find_resource() walk it; free_rd_atomic_resources()
also leaves the cached pointer qp->resp.res dangling. A local
unprivileged user can race the free/realloc into a use-after-free in
rxe_receiver() (local DoS).

Drain recv_task around the swap with rxe_disable_task()/rxe_enable_task(),
as rxe_qp_reset() already does when tearing this array down, re-enabling
only after alloc_rd_atomic_resources() succeeds so the responder never
resumes against a NULL qp->resp.resources on the ENOMEM path. Also clear
qp->resp.res in free_rd_atomic_resources(), like the rxe_resp.c
completion paths.

Reproduced under KASAN; the slab-use-after-free in rxe_receiver() is gone.

Project Subscriptions

Vendors Products
Linux Kernel Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 04 Sep 2026 19:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Fri, 04 Sep 2026 16:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp rxe_qp_from_attr() handles IB_QP_MAX_DEST_RD_ATOMIC outside the IB_QP_STATE path, so it holds no state_lock and runs while the responder task rxe_receiver() (recv_task on rxe_wq) is live. A modify_qp() setting only that attribute calls free_rd_atomic_resources() then alloc_rd_atomic_resources(), swapping qp->resp.resources[] while rxe_prepare_res()/find_resource() walk it; free_rd_atomic_resources() also leaves the cached pointer qp->resp.res dangling. A local unprivileged user can race the free/realloc into a use-after-free in rxe_receiver() (local DoS). Drain recv_task around the swap with rxe_disable_task()/rxe_enable_task(), as rxe_qp_reset() already does when tearing this array down, re-enabling only after alloc_rd_atomic_resources() succeeds so the responder never resumes against a NULL qp->resp.resources on the ENOMEM path. Also clear qp->resp.res in free_rd_atomic_resources(), like the rxe_resp.c completion paths. Reproduced under KASAN; the slab-use-after-free in rxe_receiver() is gone.
Title RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-04T15:55:18.791Z

Reserved: 2026-08-26T14:34:25.798Z

Link: CVE-2026-80864

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-04T16:18:15.737

Modified: 2026-09-04T16:18:15.737

Link: CVE-2026-80864

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-04T19:15:07Z

Weaknesses