RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.270, 5.15.221, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 2 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2026-74378
- 2026-10-03 Alias added: GHSA-7vv8-3m2v-67j6
- 2026-10-16 CISA SSVC decision points changed
References
Other 8
- https://git.kernel.org/stable/c/c8db0e5ab0b6c540214c46c56aaac7cbcb0967fe
- https://git.kernel.org/stable/c/e48daa94ad2d406225b73491fc935064716f0ec7
- https://git.kernel.org/stable/c/3cfa2a3adc51b7c57729961a03446962ff10e3d2
- https://git.kernel.org/stable/c/cd19a6345e3727adafafa5954b58b13c92e13b80
- https://git.kernel.org/stable/c/3e07ea9579dc9553d2285c26c2823931358aa3b8
- https://git.kernel.org/stable/c/02558c86b6b761063e9399e6b939984500327ef1
- https://git.kernel.org/stable/c/b9800d7953d119bcc068c74587d48e4ba0313629
- https://git.kernel.org/stable/c/22b8fbded65b8c441b634a185f8da67657df6c50
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- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-74378 · CVE Program
- CVE-2026-74378 · NVD
- FIRST EPSS
- GHSA-7vv8-3m2v-67j6 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-74378 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences