CVE-2026-92525

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

Published Sep 17, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4841-1 linux security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9022-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9023-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9024-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9025-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9026-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9039-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-9040-1 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9066-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-125
Type Values Removed Values Added
Weaknesses CWE-125
Type Values Removed Values Added
Weaknesses CWE-125
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'}

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
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 19, 2026, 9:04 AM
Reserved
Sep 16, 2026, 12:21 PM
Status
Received
Published
Sep 17, 2026, 5:17 PM
Modified
Oct 19, 2026, 10:16 AM