FKIE_CVE-2026-63891

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-19 16:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: thunderbolt: property: Cap recursion depth in __tb_property_parse_dir() A DIRECTORY entry's value field is used as the dir_offset for a recursive call into __tb_property_parse_dir() with no depth counter. A crafted peer that chains DIRECTORY entries into a back-reference loop drives the parser until the kernel stack is exhausted and the guard page fires. Any untrusted XDomain peer (cable, dock, in-line inspector, adjacent host) that reaches the PROPERTIES_REQUEST control-plane exchange can trigger this without authentication. Thread a depth counter through tb_property_parse() and __tb_property_parse_dir(), and reject blocks that exceed TB_PROPERTY_MAX_DEPTH = 8. That is comfortably larger than any observed legitimate XDomain layout. Operators who do not need XDomain host-to-host discovery can disable the path entirely with thunderbolt.xdomain=0 on the kernel command line.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0a84ab9271936c11e84e511bb52fc5682f8b6726
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2b5f47a710172c962ef42d1b732b04d2ad0dce21
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/830c8a9b467e7d3a158483d37fa7dc13892b293a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/928abe19fbf0127003abcb1ea69cabc1c897d0ab
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/95839a67ea56ca35732aad7f711404a3127cfe2d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b4621e5ef63405c317a84b711faf3bd75b3c6a94
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ed9455ef4bd9babc90f92e526abe3fb68c1a8709
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f31c6d220f455b5af63590302b30e1b932d14599
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/thunderbolt/property.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2b5f47a710172c962ef42d1b732b04d2ad0dce21",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            },
            {
              "lessThan": "95839a67ea56ca35732aad7f711404a3127cfe2d",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            },
            {
              "lessThan": "0a84ab9271936c11e84e511bb52fc5682f8b6726",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            },
            {
              "lessThan": "b4621e5ef63405c317a84b711faf3bd75b3c6a94",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            },
            {
              "lessThan": "f31c6d220f455b5af63590302b30e1b932d14599",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            },
            {
              "lessThan": "830c8a9b467e7d3a158483d37fa7dc13892b293a",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            },
            {
              "lessThan": "ed9455ef4bd9babc90f92e526abe3fb68c1a8709",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            },
            {
              "lessThan": "928abe19fbf0127003abcb1ea69cabc1c897d0ab",
              "status": "affected",
              "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/thunderbolt/property.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.15"
            },
            {
              "lessThan": "4.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "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\nthunderbolt: property: Cap recursion depth in __tb_property_parse_dir()\n\nA DIRECTORY entry\u0027s value field is used as the dir_offset for a\nrecursive call into __tb_property_parse_dir() with no depth counter.\nA crafted peer that chains DIRECTORY entries into a back-reference\nloop drives the parser until the kernel stack is exhausted and the\nguard page fires.  Any untrusted XDomain peer (cable, dock, in-line\ninspector, adjacent host) that reaches the PROPERTIES_REQUEST\ncontrol-plane exchange can trigger this without authentication.\n\nThread a depth counter through tb_property_parse() and\n__tb_property_parse_dir(), and reject blocks that exceed\nTB_PROPERTY_MAX_DEPTH = 8.  That is comfortably larger than any\nobserved legitimate XDomain layout.\n\nOperators who do not need XDomain host-to-host discovery can disable\nthe path entirely with thunderbolt.xdomain=0 on the kernel command\nline."
    }
  ],
  "id": "CVE-2026-63891",
  "lastModified": "2026-07-19T16:17:06.440",
  "metrics": {},
  "published": "2026-07-19T16:17:06.440",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0a84ab9271936c11e84e511bb52fc5682f8b6726"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2b5f47a710172c962ef42d1b732b04d2ad0dce21"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/830c8a9b467e7d3a158483d37fa7dc13892b293a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/928abe19fbf0127003abcb1ea69cabc1c897d0ab"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/95839a67ea56ca35732aad7f711404a3127cfe2d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b4621e5ef63405c317a84b711faf3bd75b3c6a94"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ed9455ef4bd9babc90f92e526abe3fb68c1a8709"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f31c6d220f455b5af63590302b30e1b932d14599"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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