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.
References8
- git.kernel.org/stable/c/02558c86b6b761063e9399e6b939984500327ef1
- git.kernel.org/stable/c/22b8fbded65b8c441b634a185f8da67657df6c50
- git.kernel.org/stable/c/3cfa2a3adc51b7c57729961a03446962ff10e3d2
- git.kernel.org/stable/c/3e07ea9579dc9553d2285c26c2823931358aa3b8
- git.kernel.org/stable/c/b9800d7953d119bcc068c74587d48e4ba0313629
- git.kernel.org/stable/c/c8db0e5ab0b6c540214c46c56aaac7cbcb0967fe
- git.kernel.org/stable/c/cd19a6345e3727adafafa5954b58b13c92e13b80
- git.kernel.org/stable/c/e48daa94ad2d406225b73491fc935064716f0ec7
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 4 · as of 11 November 2026
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