CVE-2026-74378

RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe

HIGH
7.8
CVSS Score
Published: August 15, 2026 at 05:58 AM UTC
Updated: October 16, 2026 at 07:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe get_srq_wqe() reads wqe->dma.num_sge from the shared receive queue buffer, which is mapped into userspace. It validates num_sge against max_sge, but then re-reads the same field to calculate the memcpy size. A concurrent userspace thread can modify num_sge between validation and use, causing a heap buffer overflow when copying the WQE into qp->resp.srq_wqe. Read num_sge into a local variable and use it for both the bounds check and the size calculation.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 02558c86b6b761063e9399e6b939984500327ef1 (fixed)
Vendor states this is fixed in 22b8fbded65b8c441b634a185f8da67657df6c50 (fixed)
Vendor states this is fixed in 3cfa2a3adc51b7c57729961a03446962ff10e3d2 (fixed)
Vendor states this is fixed in 3e07ea9579dc9553d2285c26c2823931358aa3b8 (fixed)
Vendor states this is fixed in b9800d7953d119bcc068c74587d48e4ba0313629 (fixed)
Vendor states this is fixed in c8db0e5ab0b6c540214c46c56aaac7cbcb0967fe (fixed)
Vendor states this is fixed in cd19a6345e3727adafafa5954b58b13c92e13b80 (fixed)
Vendor states this is fixed in e48daa94ad2d406225b73491fc935064716f0ec7 (fixed)
Vendor states this is fixed in 4.8 (unaffected)
Vendor states this is fixed in 5.10.270 (unaffected)
Vendor states this is fixed in 5.15.221 (unaffected)
Vendor states this is fixed in 6.1.178 (unaffected)
Vendor states this is fixed in 6.12.97 (unaffected)
Vendor states this is fixed in 6.18.40 (unaffected)
Vendor states this is fixed in 6.6.145 (unaffected)
Vendor states this is fixed in 7.1.5 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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