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

RDMA/rxe: Validate num_sge/cur_sge before indexing wqe->dma.sge[]

For a user QP, qp->sq.queue is a ring the application writes directly,
so rxe_post_send() takes the is_user branch and only schedules send_task
without validating the WQE. rxe_requester() consumes it in place via
req_next_wqe() and calls copy_data(), which indexes
&wqe->dma.sge[cur_sge] with the attacker-controlled num_sge/cur_sge.
Only the kernel path bounds num_sge (validate_send_wr()); the user WQE
is never checked, so a local unprivileged user can post a WQE with an
out-of-range cur_sge or oversized num_sge and force an out-of-bounds
read of the per-WQE sge array in copy_data() (vmalloc OOB read, local
DoS).

Bound num_sge to qp->sq.max_sge in rxe_requester() before use, the way
get_srq_wqe() already guards SRQ entries, and bound cur_sge only when
the WQE carries payload (dma.resid): copy_data() returns early on a
zero-length copy before touching dma->sge[], so a zero-payload WQE --
the only kind a max_sge == 0 QP can post -- stays valid.

Reproduced under KASAN; the vmalloc-out-of-bounds in copy_data() is gone.
Published: 2026-09-17
Score: n/a
EPSS: n/a
KEV: No
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Remediation

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History

Thu, 17 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Validate num_sge/cur_sge before indexing wqe->dma.sge[] For a user QP, qp->sq.queue is a ring the application writes directly, so rxe_post_send() takes the is_user branch and only schedules send_task without validating the WQE. rxe_requester() consumes it in place via req_next_wqe() and calls copy_data(), which indexes &wqe->dma.sge[cur_sge] with the attacker-controlled num_sge/cur_sge. Only the kernel path bounds num_sge (validate_send_wr()); the user WQE is never checked, so a local unprivileged user can post a WQE with an out-of-range cur_sge or oversized num_sge and force an out-of-bounds read of the per-WQE sge array in copy_data() (vmalloc OOB read, local DoS). Bound num_sge to qp->sq.max_sge in rxe_requester() before use, the way get_srq_wqe() already guards SRQ entries, and bound cur_sge only when the WQE carries payload (dma.resid): copy_data() returns early on a zero-length copy before touching dma->sge[], so a zero-payload WQE -- the only kind a max_sge == 0 QP can post -- stays valid. Reproduced under KASAN; the vmalloc-out-of-bounds in copy_data() is gone.
Title RDMA/rxe: Validate num_sge/cur_sge before indexing wqe->dma.sge[]
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-17T16:10:30.789Z

Reserved: 2026-09-16T12:21:13.875Z

Link: CVE-2026-92525

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-17T17:17:55.540

Modified: 2026-09-17T17:17:55.540

Link: CVE-2026-92525

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.