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GHSA-M7QH-P3GF-GCV8

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

iommufd: Set upper bounds on cache invalidation entry_num and entry_len

iommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len, each bounded only by U32_MAX. An entry_len beyond the kernel's struct size makes the copy helper verify the extra bytes are zero, scanning that excess in one uninterruptible pass; a multi-gigabyte value over zeroed user memory trips the soft-lockup watchdog.

A large entry_num is the other half, driving the backend invalidation loop with no reschedule. The VT-d nested handler, for one, copies each entry and flushes caches per iteration, pinning the CPU on a non-preemptible kernel.

Cap both in the ioctl. entry_len is held under PAGE_SIZE, above any request struct, and entry_num under 1 << 19, the order of a hardware invalidation queue and well beyond any real batch, bounding the per-call loop length.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64289"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:09Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Set upper bounds on cache invalidation entry_num and entry_len\n\niommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len,\neach bounded only by U32_MAX. An entry_len beyond the kernel\u0027s struct size\nmakes the copy helper verify the extra bytes are zero, scanning that excess\nin one uninterruptible pass; a multi-gigabyte value over zeroed user memory\ntrips the soft-lockup watchdog.\n\nA large entry_num is the other half, driving the backend invalidation loop\nwith no reschedule. The VT-d nested handler, for one, copies each entry and\nflushes caches per iteration, pinning the CPU on a non-preemptible kernel.\n\nCap both in the ioctl. entry_len is held under PAGE_SIZE, above any request\nstruct, and entry_num under 1 \u003c\u003c 19, the order of a hardware invalidation\nqueue and well beyond any real batch, bounding the per-call loop length.",
  "id": "GHSA-m7qh-p3gf-gcv8",
  "modified": "2026-07-25T12:31:29Z",
  "published": "2026-07-25T12:31:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64289"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c6381d90898089287e0a358f06f89f6b4b389f2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/32ca4aed2a66205b072fcfecabe220289a8149ff"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4d70986002f2f3eaaed89124fb2522bded38b016"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d2bd041e0efaf7d81789779b135279d18b33d6d5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-64289 (GCVE-0-2026-64289)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-07-25 08:49

Title

iommufd: Set upper bounds on cache invalidation entry_num and entry_len

Summary

In the Linux kernel, the following vulnerability has been resolved: iommufd: Set upper bounds on cache invalidation entry_num and entry_len iommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len, each bounded only by U32_MAX. An entry_len beyond the kernel's struct size makes the copy helper verify the extra bytes are zero, scanning that excess in one uninterruptible pass; a multi-gigabyte value over zeroed user memory trips the soft-lockup watchdog. A large entry_num is the other half, driving the backend invalidation loop with no reschedule. The VT-d nested handler, for one, copies each entry and flushes caches per iteration, pinning the CPU on a non-preemptible kernel. Cap both in the ioctl. entry_len is held under PAGE_SIZE, above any request struct, and entry_num under 1 << 19, the order of a hardware invalidation queue and well beyond any real batch, bounding the per-call loop length.

Severity

No CVSS data available.

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/d2bd041e0efaf7d81…
https://git.kernel.org/stable/c/32ca4aed2a66205b0…
https://git.kernel.org/stable/c/2c6381d9089808928…
https://git.kernel.org/stable/c/4d70986002f2f3eaa…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8c6eabae3807e048b9f17733af5e20500fbf858c , < d2bd041e0efaf7d81789779b135279d18b33d6d5 (git) Affected: 8c6eabae3807e048b9f17733af5e20500fbf858c , < 32ca4aed2a66205b072fcfecabe220289a8149ff (git) Affected: 8c6eabae3807e048b9f17733af5e20500fbf858c , < 2c6381d90898089287e0a358f06f89f6b4b389f2 (git) Affected: 8c6eabae3807e048b9f17733af5e20500fbf858c , < 4d70986002f2f3eaaed89124fb2522bded38b016 (git)
Linux	Linux	Affected: 6.8 Unaffected: 0 , < 6.8 (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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{
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/hw_pagetable.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "d2bd041e0efaf7d81789779b135279d18b33d6d5",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "32ca4aed2a66205b072fcfecabe220289a8149ff",
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              "versionType": "git"
            }
          ]
        },
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          ],
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.8"
            },
            {
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Set upper bounds on cache invalidation entry_num and entry_len\n\niommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len,\neach bounded only by U32_MAX. An entry_len beyond the kernel\u0027s struct size\nmakes the copy helper verify the extra bytes are zero, scanning that excess\nin one uninterruptible pass; a multi-gigabyte value over zeroed user memory\ntrips the soft-lockup watchdog.\n\nA large entry_num is the other half, driving the backend invalidation loop\nwith no reschedule. The VT-d nested handler, for one, copies each entry and\nflushes caches per iteration, pinning the CPU on a non-preemptible kernel.\n\nCap both in the ioctl. entry_len is held under PAGE_SIZE, above any request\nstruct, and entry_num under 1 \u003c\u003c 19, the order of a hardware invalidation\nqueue and well beyond any real batch, bounding the per-call loop length."
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      "providerMetadata": {
        "dateUpdated": "2026-07-25T08:49:29.434Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
          "url": "https://git.kernel.org/stable/c/4d70986002f2f3eaaed89124fb2522bded38b016"
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    "datePublished": "2026-07-25T08:49:29.434Z",
    "dateReserved": "2026-07-19T15:36:31.778Z",
    "dateUpdated": "2026-07-25T08:49:29.434Z",
    "state": "PUBLISHED"
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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.

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GHSA-M7QH-P3GF-GCV8

CVE-2026-64289 (GCVE-0-2026-64289)

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Sightings

Nomenclature