FKIE_CVE-2026-64588

Vulnerability from fkie_nvd - Published: 2026-08-06 08:16 - Updated: 2026-08-08 15:16
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix data races on ring->ready On weakly-ordered architectures, the store to fiq->ops can be reordered past the store to ring->ready, allowing a CPU that sees ring->ready == true via fuse_uring_ready() to dispatch requests through a stale fiq->ops pointer. Upgrade the store to smp_store_release() and the load in fuse_uring_ready() to smp_load_acquire() so that the preceding WRITE_ONCE(fiq->ops, ...) is visible to any CPU that observes ring->ready == true. Additionally, fuse_uring_do_register() publishes ring->ready with WRITE_ONCE() but the fast-path check reads it with a plain load. This is a marked-vs-unmarked access that KCSAN will flag. Wrap it in READ_ONCE() to mark it without adding unnecessary ordering. Also wrap the fc->ring load in fuse_uring_ready() in READ_ONCE() to prevent the compiler from reloading it between the NULL check and the dereference.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/46725a0056c884cf58a6897f222892807327d82d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b156bb9966972122b148acab8bdf415cdb8176a3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d01a09b442cb786cd44ccc7c84d57e2856d6737c
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev_uring.c",
            "fs/fuse/dev_uring_i.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b156bb9966972122b148acab8bdf415cdb8176a3",
              "status": "affected",
              "version": "c2c9af9a0b13261c36909036057a116f2edb5e1a",
              "versionType": "git"
            },
            {
              "lessThan": "d01a09b442cb786cd44ccc7c84d57e2856d6737c",
              "status": "affected",
              "version": "c2c9af9a0b13261c36909036057a116f2edb5e1a",
              "versionType": "git"
            },
            {
              "lessThan": "46725a0056c884cf58a6897f222892807327d82d",
              "status": "affected",
              "version": "c2c9af9a0b13261c36909036057a116f2edb5e1a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev_uring.c",
            "fs/fuse/dev_uring_i.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix data races on ring-\u003eready\n\nOn weakly-ordered architectures, the store to fiq-\u003eops can be\nreordered past the store to ring-\u003eready, allowing a CPU that sees\nring-\u003eready == true via fuse_uring_ready() to dispatch requests\nthrough a stale fiq-\u003eops pointer. Upgrade the store to\nsmp_store_release() and the load in fuse_uring_ready() to\nsmp_load_acquire() so that the preceding WRITE_ONCE(fiq-\u003eops, ...)\nis visible to any CPU that observes ring-\u003eready == true.\n\nAdditionally, fuse_uring_do_register() publishes ring-\u003eready with\nWRITE_ONCE() but the fast-path check reads it with a plain load.\nThis is a marked-vs-unmarked access that KCSAN will flag. Wrap it in\nREAD_ONCE() to mark it without adding unnecessary ordering.\n\nAlso wrap the fc-\u003ering load in fuse_uring_ready() in READ_ONCE() to\nprevent the compiler from reloading it between the NULL check and the\ndereference."
    }
  ],
  "id": "CVE-2026-64588",
  "lastModified": "2026-08-08T15:16:34.170",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-06T08:16:34.123",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/46725a0056c884cf58a6897f222892807327d82d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b156bb9966972122b148acab8bdf415cdb8176a3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d01a09b442cb786cd44ccc7c84d57e2856d6737c"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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