FKIE_CVE-2026-63968

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-20 15:16
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible infinite loop in fib6_select_path() Found while auditing the same pattern Sashiko reported in rt6_fill_node() [1]. Apply the same fix as commit f8d8ce1b515a ("ipv6: fix possible infinite loop in fib6_info_uses_dev()"). Writers holding tb6_lock can list_del_rcu(&first->fib6_siblings) without waiting for RCU readers; first->fib6_siblings.next then still points into the old ring and this softirq-side walker never reaches &first->fib6_siblings as its terminator. fib6_purge_rt() always WRITE_ONCE()s first->fib6_nsiblings to 0 before list_del_rcu(), so an inside-loop check is a reliable detach signal. [1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0f7b73c3452635de83b8711b31abdda8e49aad7b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3948a7d92f7678e89e1776bb2d169afcad63b1ae
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9b9d5bd6e3d4c9cecab5407604b690684b2532d2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9c7da87c2dc860bb17ca1ece942495d28b1ce3b9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ab9a10969a907b472a0196d999c08ff7144172e3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c87cd3cb309634bc8f50a54e2079424f219ac21f
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/route.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3948a7d92f7678e89e1776bb2d169afcad63b1ae",
              "status": "affected",
              "version": "d0ec61c9f3583b76aebdbb271f5c0d3fcccd48b2",
              "versionType": "git"
            },
            {
              "lessThan": "c87cd3cb309634bc8f50a54e2079424f219ac21f",
              "status": "affected",
              "version": "52da02521ede55fb86546c3fffd9377b3261b91f",
              "versionType": "git"
            },
            {
              "lessThan": "0f7b73c3452635de83b8711b31abdda8e49aad7b",
              "status": "affected",
              "version": "34a949e7a0869dfa31a40416d2a56973fae1807b",
              "versionType": "git"
            },
            {
              "lessThan": "ab9a10969a907b472a0196d999c08ff7144172e3",
              "status": "affected",
              "version": "d9ccb18f83ea2bb654289b6ecf014fd267cc988b",
              "versionType": "git"
            },
            {
              "lessThan": "9b9d5bd6e3d4c9cecab5407604b690684b2532d2",
              "status": "affected",
              "version": "d9ccb18f83ea2bb654289b6ecf014fd267cc988b",
              "versionType": "git"
            },
            {
              "lessThan": "9c7da87c2dc860bb17ca1ece942495d28b1ce3b9",
              "status": "affected",
              "version": "d9ccb18f83ea2bb654289b6ecf014fd267cc988b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "11edcd026012ac18acee0f1514db3ed1b160fc6f",
              "versionType": "git"
            },
            {
              "lessThan": "6.1.176",
              "status": "affected",
              "version": "6.1.128",
              "versionType": "semver"
            },
            {
              "lessThan": "6.6.143",
              "status": "affected",
              "version": "6.6.75",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12.93",
              "status": "affected",
              "version": "6.12.2",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12",
              "status": "affected",
              "version": "6.11.11",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/route.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "status": "unaffected",
              "version": "0",
              "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\nipv6: fix possible infinite loop in fib6_select_path()\n\nFound while auditing the same pattern Sashiko reported in\nrt6_fill_node() [1]. Apply the same fix as\ncommit f8d8ce1b515a (\"ipv6: fix possible infinite loop in fib6_info_uses_dev()\").\n\nWriters holding tb6_lock can list_del_rcu(\u0026first-\u003efib6_siblings)\nwithout waiting for RCU readers; first-\u003efib6_siblings.next then\nstill points into the old ring and this softirq-side walker never\nreaches \u0026first-\u003efib6_siblings as its terminator. fib6_purge_rt()\nalways WRITE_ONCE()s first-\u003efib6_nsiblings to 0 before\nlist_del_rcu(), so an inside-loop check is a reliable detach signal.\n\n[1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev"
    }
  ],
  "id": "CVE-2026-63968",
  "lastModified": "2026-07-20T15:16:59.157",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T16:17:15.830",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0f7b73c3452635de83b8711b31abdda8e49aad7b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3948a7d92f7678e89e1776bb2d169afcad63b1ae"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9b9d5bd6e3d4c9cecab5407604b690684b2532d2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9c7da87c2dc860bb17ca1ece942495d28b1ce3b9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ab9a10969a907b472a0196d999c08ff7144172e3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c87cd3cb309634bc8f50a54e2079424f219ac21f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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