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CVE-2026-97990

📛 CVE Title

vdpa_sim_net: check TX pull result before RX copy

Description

In the Linux kernel, the following vulnerability has been resolved: vdpa_sim_net: check TX pull result before RX copy vringh_iov_pull_iotlb() returns a signed byte count. A failed TX pull is currently added to the unsigned byte counter and then passed as a size_t length to receive_filter() and vringh_iov_push_iotlb(). A negative error can therefore become a large length in the RX path. Handle non-positive pull results before every length use. Count the TX error and complete the consumed TX descriptor with zero bytes. I found this bug myself, though the patch was written with AI assistance.

Overview

State
PUBLISHED
Assigner (CNA)
Linux
CVSS severity
HIGH
CVSS score
CVSS 7.5 / 10 7.5 7.5 / 10
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:H
Effective score
7.5 / 10 HIGH source: CNA overview
CWE(s)
—
Reserved
2026-09-25
Published
2026-09-25 10:23 UTC
Last updated
2026-09-25 14:41 UTC
Source
https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/97xxx/CVE-2026-97990.json
Linked Threat
CVE-2026-97990 — vdpa_sim_net: check TX pull result before RX copy

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published
2026-09-25 11:17:27 UTC
NVD last modified
2026-09-25 15:18:03 UTC
NVD CVSS v3.1
CVSS 7.5 / 10 7.5 7.5 / 10 HIGH source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:H
Exploitability subscore
1.1 / 10
Impact subscore
5.8 / 10

NVD / KEV / EPSS data refreshed 2026-09-26 04:25 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.

Affected products (2)

VendorProductVersionsPlatforms
Linux Linux cfe226892913a448e83e7a19db93862baa3cb99c (affected), cfe226892913a448e83e7a19db93862baa3cb99c (affected), cfe226892913a448e83e7a19db93862baa3cb99c (affected), cfe226892913a448e83e7a19db93862baa3cb99c (affected) —
Linux Linux 5.19 (affected), 0 (unaffected), 6.12.111 (unaffected), 6.18.53 (unaffected), 7.2.7 (unaffected), 7.3-rc3 (unaffected) —

Vendor references (4)

References embedded in the original CVE record by the assigning CNA.

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (4)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-97990.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/vdpa/vdpa_sim/vdpa_sim_net.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c001abcde865b74231da8f1412c3217dbf66781e",
              "status": "affected",
              "version": "cfe226892913a448e83e7a19db93862baa3cb99c",
              "versionType": "git"
            },
            {
              "lessThan": "3af20238a09ca180d66623e3bed16b64e9975f39",
              "status": "affected",
              "version": "cfe226892913a448e83e7a19db93862baa3cb99c",
              "versionType": "git"
            },
            {
              "lessThan": "2bbf1c1f69991e28787e02b0a2f826289d5fc730",
              "status": "affected",
              "version": "cfe226892913a448e83e7a19db93862baa3cb99c",
              "versionType": "git"
            },
            {
              "lessThan": "0d195797a80b77f2ec56718cd26d3ee65d0093e8",
              "status": "affected",
              "version": "cfe226892913a448e83e7a19db93862baa3cb99c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/vdpa/vdpa_sim/vdpa_sim_net.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.7",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc3",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvdpa_sim_net: check TX pull result before RX copy\n\nvringh_iov_pull_iotlb() returns a signed byte count.  A failed TX pull is\ncurrently added to the unsigned byte counter and then passed as a size_t\nlength to receive_filter() and vringh_iov_push_iotlb().  A negative error\ncan therefore become a large length in the RX path.\n\nHandle non-positive pull results before every length use.  Count the TX\nerror and complete the consumed TX descriptor with zero bytes.\n\nI found this bug myself, though the patch was written with AI assistance."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The malformed input is a virtqueue TX descriptor with an unmapped address, written into the vring by whoever drives the vdpa_sim_net device (a guest via vhost-vdpa or a local vhost-vdpa user). vdpasim_net_work() processes it and no network protocol carries it.\nAC:H - Once reached, the failed vringh_iov_pull_iotlb() is deterministic. But it requires an admin to create a vdpa_sim_net device (a test-only simulator under RUNTIME_TESTING_MENU) and assign it to the attacker's VM or process, a configuration the attacker cannot produce.\nPR:L - Device creation needs GENL_ADMIN_PERM in init_net (not reachable via user namespaces). The attacker is the guest or process given the device, which only needs ordinary control of its own virtqueues and no host privileges.\nUI:N - The attacker queues a broadcast TX frame, then a TX descriptor that fails IOTLB translation, plus large RX descriptors, all on their own rings. No victim action is needed.\nS:C - A guest driving vdpa_sim_net through vhost-vdpa causes the host kernel to copy host heap memory into guest-visible RX buffers, crossing the VM-to-host boundary.\nC:H - The negative read, cast to size_t, is passed to vringh_iov_push_iotlb(). It copies from the PAGE_SIZE net->buffer up to the attacker-sized RX iov, leaking adjacent host kernel heap (an out-of-bounds read not limited to a few bytes) into attacker memory.\nI:N - The overlong copy only reads kernel memory and writes into the attacker's own RX buffers; no kernel memory is written. The only other effect is corrupted tx_bytes statistics.\nA:H - A large RX descriptor chain makes the out-of-bounds read of net->buffer run into unmapped memory, oopsing the host kernel and taking down every guest on it."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-25T14:41:47.453Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c001abcde865b74231da8f1412c3217dbf66781e"
        },
        {
          "url": "https://git.kernel.org/stable/c/3af20238a09ca180d66623e3bed16b64e9975f39"
        },
        {
          "url": "https://git.kernel.org/stable/c/2bbf1c1f69991e28787e02b0a2f826289d5fc730"
        },
        {
          "url": "https://git.kernel.org/stable/c/0d195797a80b77f2ec56718cd26d3ee65d0093e8"
        }
      ],
      "title": "vdpa_sim_net: check TX pull result before RX copy",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-97990",
    "datePublished": "2026-09-25T10:23:23.226Z",
    "dateReserved": "2026-09-25T10:18:58.209Z",
    "dateUpdated": "2026-09-25T14:41:47.453Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}