FKIE_CVE-2026-64292

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-30 15:00
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: iommufd: Move vevent memory allocation outside spinlock The veventq memory allocation happens inside the spinlock. Given its depth is decided by the user space, this leaves a vulnerability, where userspace can allocate large queues to exhaust atomic memory reserves. Move the allocation outside the spinlock and use GFP_NOWAIT, which can fail fast under memory pressure without dipping into the GFP_ATOMIC reserves or direct-reclaiming from the threaded IRQ handler. On allocation failure, queue the lost_events_header (so userspace learns of the drop) and return -ENOMEM so the caller learns of the kernel-side memory pressure. This is intentionally distinct from the queue-overflow path, which also queues the lost_events_header but returns 0: a full queue is an expected userspace-pacing condition rather than a kernel error. A subsequent change will cap the upper bound of the veventq_depth.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/47443565d10c51366c9382dbc8597cd6c460b8a2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6c5fc40200cd0a87d66a368eee00df4d1cca946e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/779480ea79551c31964e74b9aef0e730faa3aa11
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/driver.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "779480ea79551c31964e74b9aef0e730faa3aa11",
              "status": "affected",
              "version": "e36ba5ab808ef6237c3148d469c8238674230e2b",
              "versionType": "git"
            },
            {
              "lessThan": "6c5fc40200cd0a87d66a368eee00df4d1cca946e",
              "status": "affected",
              "version": "e36ba5ab808ef6237c3148d469c8238674230e2b",
              "versionType": "git"
            },
            {
              "lessThan": "47443565d10c51366c9382dbc8597cd6c460b8a2",
              "status": "affected",
              "version": "e36ba5ab808ef6237c3148d469c8238674230e2b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/driver.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Move vevent memory allocation outside spinlock\n\nThe veventq memory allocation happens inside the spinlock. Given its depth\nis decided by the user space, this leaves a vulnerability, where userspace\ncan allocate large queues to exhaust atomic memory reserves.\n\nMove the allocation outside the spinlock and use GFP_NOWAIT, which can fail\nfast under memory pressure without dipping into the GFP_ATOMIC reserves or\ndirect-reclaiming from the threaded IRQ handler. On allocation failure,\nqueue the lost_events_header (so userspace learns of the drop) and return\n-ENOMEM so the caller learns of the kernel-side memory pressure.\n\nThis is intentionally distinct from the queue-overflow path, which also\nqueues the lost_events_header but returns 0: a full queue is an expected\nuserspace-pacing condition rather than a kernel error.\n\nA subsequent change will cap the upper bound of the veventq_depth."
    }
  ],
  "id": "CVE-2026-64292",
  "lastModified": "2026-07-30T15:00:27.343",
  "metrics": {},
  "published": "2026-07-25T10:17:09.937",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/47443565d10c51366c9382dbc8597cd6c460b8a2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6c5fc40200cd0a87d66a368eee00df4d1cca946e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/779480ea79551c31964e74b9aef0e730faa3aa11"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}



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