Vulnerability-Lookup

GHSA-7VV8-3M2V-67J6

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74378"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:39Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe\n\nget_srq_wqe() reads wqe-\u003edma.num_sge from the shared receive queue\nbuffer, which is mapped into userspace. It validates num_sge against\nmax_sge, but then re-reads the same field to calculate the memcpy\nsize. A concurrent userspace thread can modify num_sge between\nvalidation and use, causing a heap buffer overflow when copying the\nWQE into qp-\u003eresp.srq_wqe.\n\nRead num_sge into a local variable and use it for both the bounds\ncheck and the size calculation.",
  "id": "GHSA-7vv8-3m2v-67j6",
  "modified": "2026-08-17T06:33:41Z",
  "published": "2026-08-15T06:32:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74378"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/02558c86b6b761063e9399e6b939984500327ef1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/22b8fbded65b8c441b634a185f8da67657df6c50"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3cfa2a3adc51b7c57729961a03446962ff10e3d2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3e07ea9579dc9553d2285c26c2823931358aa3b8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b9800d7953d119bcc068c74587d48e4ba0313629"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd19a6345e3727adafafa5954b58b13c92e13b80"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74378 (GCVE-0-2026-74378)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:58 – Updated: 2026-08-17 05:46

Title

RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe

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.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

6 references

URL	Tags
https://git.kernel.org/stable/c/3cfa2a3adc51b7c57…
https://git.kernel.org/stable/c/cd19a6345e3727ada…
https://git.kernel.org/stable/c/3e07ea9579dc9553d…
https://git.kernel.org/stable/c/02558c86b6b761063…
https://git.kernel.org/stable/c/b9800d7953d119bcc…
https://git.kernel.org/stable/c/22b8fbded65b8c441…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8700e3e7c4857d28ebaa824509934556da0b3e76 , < 3cfa2a3adc51b7c57729961a03446962ff10e3d2 (git) Affected: 8700e3e7c4857d28ebaa824509934556da0b3e76 , < cd19a6345e3727adafafa5954b58b13c92e13b80 (git) Affected: 8700e3e7c4857d28ebaa824509934556da0b3e76 , < 3e07ea9579dc9553d2285c26c2823931358aa3b8 (git) Affected: 8700e3e7c4857d28ebaa824509934556da0b3e76 , < 02558c86b6b761063e9399e6b939984500327ef1 (git) Affected: 8700e3e7c4857d28ebaa824509934556da0b3e76 , < b9800d7953d119bcc068c74587d48e4ba0313629 (git) Affected: 8700e3e7c4857d28ebaa824509934556da0b3e76 , < 22b8fbded65b8c441b634a185f8da67657df6c50 (git)
Linux	Linux	Affected: 4.8 Unaffected: 0 , < 4.8 (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_resp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3cfa2a3adc51b7c57729961a03446962ff10e3d2",
              "status": "affected",
              "version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
              "versionType": "git"
            },
            {
              "lessThan": "cd19a6345e3727adafafa5954b58b13c92e13b80",
              "status": "affected",
              "version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
              "versionType": "git"
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            {
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              "status": "affected",
              "version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "b9800d7953d119bcc068c74587d48e4ba0313629",
              "status": "affected",
              "version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
              "versionType": "git"
            },
            {
              "lessThan": "22b8fbded65b8c441b634a185f8da67657df6c50",
              "status": "affected",
              "version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
              "versionType": "git"
            }
          ]
        },
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          "defaultStatus": "affected",
          "product": "Linux",
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          "versions": [
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              "status": "affected",
              "version": "4.8"
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            {
              "lessThan": "4.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
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            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
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        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.178",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "4.8",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe\n\nget_srq_wqe() reads wqe-\u003edma.num_sge from the shared receive queue\nbuffer, which is mapped into userspace. It validates num_sge against\nmax_sge, but then re-reads the same field to calculate the memcpy\nsize. A concurrent userspace thread can modify num_sge between\nvalidation and use, causing a heap buffer overflow when copying the\nWQE into qp-\u003eresp.srq_wqe.\n\nRead num_sge into a local variable and use it for both the bounds\ncheck and the size calculation."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Exploitation requires a local process with mmap write access to the SRQ receive queue shared with the kernel; although incoming RoCE/UDP packets trigger get_srq_wqe(), a remote peer cannot modify num_sge in the victim\u0027s userspace-mapped WQE buffer, so the TOCTOU overflow cannot be achieved from the network alone.\nAC:L - The attacker controls both sides of the race: a userspace thread that repeatedly rewrites num_sge in the mmap\u0027d SRQ entry and the thread/process that posts recv WQEs and receives the triggering RoCE Send/Write packet, making the TOCTOU window reliably winnable without external timing luck.\nPR:L - An unprivileged local user with access to /dev/infiniband/uverbs can create an SRQ (mmap\u0027d queue), associate a QP, and post recv buffers via ibverbs; rxe device setup via \"rdma link add type rxe\" is reachable with CAP_NET_ADMIN inside a user namespace (unshare -Urn).\nUI:N - No victim user interaction is required; the attacker operates their own malicious RDMA userspace process and can self-trigger the vulnerable responder path with RoCE request packets once SRQ/QP resources are configured.\nS:U - The heap overflow corrupts kernel memory within the rxe_qp responder context on the same host kernel, enabling local privilege escalation rather than crossing a VM, container, or IOMMU security boundary to impact a different authority.\nC:H - The attacker-controlled memcpy size causes an out-of-bounds copy from the mmap\u0027d SRQ ring buffer and overflows the fixed qp-\u003eresp.srq_wqe kernel buffer, enabling adjacent kernel heap data disclosure and providing primitives that can be developed into arbitrary kernel memory reads.\nI:H - Overflowing qp-\u003eresp.srq_wqe corrupts subsequent fields in rxe_resp_info/rxe_qp (e.g., responder resource pointers and state), giving a kernel heap buffer overflow that can be leveraged for arbitrary kernel memory writes and local privilege escalation.\nA:H - Corrupting responder state inside rxe_qp can cause kernel oops/panic or wedged RDMA processing during packet handling; even failed exploitation attempts can crash the kernel through use of corrupted function pointers and queue state."
            }
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        }
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        "dateUpdated": "2026-08-17T05:46:30.843Z",
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          "url": "https://git.kernel.org/stable/c/b9800d7953d119bcc068c74587d48e4ba0313629"
        },
        {
          "url": "https://git.kernel.org/stable/c/22b8fbded65b8c441b634a185f8da67657df6c50"
        }
      ],
      "title": "RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe",
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        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74378",
    "datePublished": "2026-08-15T05:58:56.381Z",
    "dateReserved": "2026-08-15T05:44:03.890Z",
    "dateUpdated": "2026-08-17T05:46:30.843Z",
    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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GHSA-7VV8-3M2V-67J6

CVE-2026-74378 (GCVE-0-2026-74378)

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Sightings

Nomenclature