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CVE-2026-89548

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: always drain cache_cleaner before destroying a cache_detail sunrpc_destroy_cache_detail() only cancels the global cache_cleaner delayed_work when cache_list is empty. During per-netns teardown cache_list is never empty because init_net's caches remain registered, so the cancel never fires. After unlink, the caller proceeds to cache_destroy_net() which kfrees the cache_detail while cache_clean() may still hold a dangling pointer to it. The result is a use-after-free: cache_dequeue() takes cd->queue_lock on freed memory, and cache_put() dereferences cd->cache_put as a function pointer from freed slab. Drop the list_empty guard so that cancel_delayed_work_sync() always runs, ensuring any in-flight cache_clean() completes before the cache_detail is freed. Re-arm the cleaner afterwards if other caches are still registered.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-11 20:19:38.250000
Last modified
2026-10-19 09:17:49.957000
View original CVE JSON 
{
  "id": "CVE-2026-89548",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:38.250",
  "lastModified": "2026-10-19T09:17:49.957",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: always drain cache_cleaner before destroying a cache_detail\n\nsunrpc_destroy_cache_detail() only cancels the global cache_cleaner\ndelayed_work when cache_list is empty.  During per-netns teardown\ncache_list is never empty because init_net's caches remain registered,\nso the cancel never fires.  After unlink, the caller proceeds to\ncache_destroy_net() which kfrees the cache_detail while cache_clean()\nmay still hold a dangling pointer to it.  The result is a\nuse-after-free: cache_dequeue() takes cd->queue_lock on freed memory,\nand cache_put() dereferences cd->cache_put as a function pointer from\nfreed slab.\n\nDrop the list_empty guard so that cancel_delayed_work_sync() always\nruns, ensuring any in-flight cache_clean() completes before the\ncache_detail is freed.  Re-arm the cleaner afterwards if other caches\nare still registered."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/sunrpc/cache.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "dec787a15c96a5665e9ffc61b429a6a4ab26e6b9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "5eea874a696201c31e7c2d7badbfa0d90e9961b5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "cf239de7fdcc8336259b01ea4bcf650dadad1040",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "6d74ecc2be120a0c300b224b7649fe93c0453714",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "9d44836f60c8c29bcdb1471fd9202387c642a890",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "2e861ce2aaa468351a6a47c4cbb4971ebb740c7b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "3d60fdf951143d6ef4e352e2f8eb852286701726",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8",
              "lessThan": "f42d0fda0c67695db6bc704b04b7c10240805377",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/sunrpc/cache.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3.4",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.4",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.270",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.221",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.109",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.50",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T19:23:39.938577Z",
          "id": "CVE-2026-89548",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2e861ce2aaa468351a6a47c4cbb4971ebb740c7b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3d60fdf951143d6ef4e352e2f8eb852286701726",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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    }
  ]
}