FKIE_CVE-2026-64452

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-27 05:16
Severity
7.1 (High) - CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: 6lowpan: fix NHC entry use-after-free on error path lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding lowpan_nhc_lock. If the descriptor has no uncompress callback, the error path drops the lock before printing nhc->name. lowpan_nhc_del() removes descriptors under the same lock and then relies on synchronize_net() before the owning module can be unloaded. That only waits for net RX RCU readers. lowpan_header_decompress() is also exported and can be reached from callers that are not necessarily covered by the net core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive path. This leaves a race where one task drops lowpan_nhc_lock in the error path, another task unregisters and frees the matching descriptor after synchronize_net() returns, and the first task then dereferences nhc->name for the warning. With the post-unlock window widened, KASAN reports: BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220 Read of size 8 lowpan_nhc_do_uncompression lowpan_header_decompress Fix this by printing the warning before dropping lowpan_nhc_lock, so the descriptor name is read while unregister is still excluded. The malformed packet is still rejected with -ENOTSUPP.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0beccbcf50de125be5520d0ffc59af4bb8655482
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1720db928e5a58ca7d75ac1d514c3b73fd7061a7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/80b5c8779acee0550845394fb3e5176a398aa24c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9c2f5c0829a8c8b904dae36be6d8056b719ac605
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a8e3a94711134e898c6021a6b77374efa91b3639
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b713aa0cc344f10f7a9928a230b5f5e780d04078
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cc27aea4d454abfb385ee2c9499c78b96db9b728
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/6lowpan/nhc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9c2f5c0829a8c8b904dae36be6d8056b719ac605",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            },
            {
              "lessThan": "80b5c8779acee0550845394fb3e5176a398aa24c",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            },
            {
              "lessThan": "cc27aea4d454abfb385ee2c9499c78b96db9b728",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            },
            {
              "lessThan": "a8e3a94711134e898c6021a6b77374efa91b3639",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            },
            {
              "lessThan": "593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            },
            {
              "lessThan": "0beccbcf50de125be5520d0ffc59af4bb8655482",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            },
            {
              "lessThan": "b713aa0cc344f10f7a9928a230b5f5e780d04078",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            },
            {
              "lessThan": "1720db928e5a58ca7d75ac1d514c3b73fd7061a7",
              "status": "affected",
              "version": "92aa7c65d295f3cbb96904afe335f683e55584b8",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/6lowpan/nhc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.1"
            },
            {
              "lessThan": "4.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\n6lowpan: fix NHC entry use-after-free on error path\n\nlowpan_nhc_do_uncompression() looks up an NHC descriptor while holding\nlowpan_nhc_lock.  If the descriptor has no uncompress callback, the error\npath drops the lock before printing nhc-\u003ename.\n\nlowpan_nhc_del() removes descriptors under the same lock and then relies\non synchronize_net() before the owning module can be unloaded.  That only\nwaits for net RX RCU readers.  lowpan_header_decompress() is also exported\nand can be reached from callers that are not necessarily covered by the net\ncore RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive\npath.\n\nThis leaves a race where one task drops lowpan_nhc_lock in the error path,\nanother task unregisters and frees the matching descriptor after\nsynchronize_net() returns, and the first task then dereferences nhc-\u003ename\nfor the warning.\n\nWith the post-unlock window widened, KASAN reports:\n\n  BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220\n  Read of size 8\n  lowpan_nhc_do_uncompression\n  lowpan_header_decompress\n\nFix this by printing the warning before dropping lowpan_nhc_lock, so the\ndescriptor name is read while unregister is still excluded.  The malformed\npacket is still rejected with -ENOTSUPP."
    }
  ],
  "id": "CVE-2026-64452",
  "lastModified": "2026-07-27T05:16:52.080",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.2,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-25T10:17:30.140",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0beccbcf50de125be5520d0ffc59af4bb8655482"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1720db928e5a58ca7d75ac1d514c3b73fd7061a7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/80b5c8779acee0550845394fb3e5176a398aa24c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9c2f5c0829a8c8b904dae36be6d8056b719ac605"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a8e3a94711134e898c6021a6b77374efa91b3639"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b713aa0cc344f10f7a9928a230b5f5e780d04078"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc27aea4d454abfb385ee2c9499c78b96db9b728"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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