GHSA-C2HG-PGQH-6WP2

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31
VLAI
Details

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

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-63968"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:15Z",
    "severity": "HIGH"
  },
  "details": "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": "GHSA-c2hg-pgqh-6wp2",
  "modified": "2026-07-20T15:31:53Z",
  "published": "2026-07-19T18:31:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63968"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f7b73c3452635de83b8711b31abdda8e49aad7b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3948a7d92f7678e89e1776bb2d169afcad63b1ae"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9b9d5bd6e3d4c9cecab5407604b690684b2532d2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9c7da87c2dc860bb17ca1ece942495d28b1ce3b9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ab9a10969a907b472a0196d999c08ff7144172e3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c87cd3cb309634bc8f50a54e2079424f219ac21f"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.