{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "73f646cec35477b5099d7e952297cb9e1855be45"
            },
            {
              "fixed": "2be741ad565c610871a6a95062c12c39da7168fd"
            },
            {
              "fixed": "69d209461c110388710e483a130caf051e4fd09a"
            },
            {
              "fixed": "de017c22135f545ca4e65d1eada22887b64958eb"
            },
            {
              "fixed": "47ba70891b10b2feb52462086b7fcd2ad75d3ce3"
            },
            {
              "fixed": "a714d62513befef37f71f4ae89bb1fe173b65f2e"
            },
            {
              "fixed": "c3f2347a47754eac690967cfd82cb6d559817b07"
            },
            {
              "fixed": "5558a8312452ddb21eff22b1cbd84302ad951944"
            },
            {
              "fixed": "cba9ccb47e9fa4cc77692fb896cc5ab57a667882"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.4.0"
            },
            {
              "fixed": "5.10.265"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.152"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.104"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.45"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74609.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: read le-\u003elink under the node lock in tipc_node_link_down()\n\ntipc_node_link_down() caches the link pointer before taking n-\u003elock:\n\n\tstruct tipc_link *l = le-\u003elink;\t\t/* unlocked */\n\n\tif (!l)\n\t\treturn;\n\ttipc_node_write_lock(n);\n\tif (!tipc_link_is_establishing(l)) {\t/* deref l */\n\t...\n\t\ttipc_link_reset(l);\t\t/* write into l */\n\tif (delete) {\n\t\tkfree(l);\n\t\tle-\u003elink = NULL;\n\nThe delete=true caller frees that very object under n-\u003elock, so the lock\ndoes not protect the cached pointer against it:\n\n - CPU A, delete=false: tipc_rcv() on TIPC_LINK_DOWN_EVT, or the link\n   supervision timer via tipc_node_timeout(), reads l unlocked and then\n   dereferences it under n-\u003elock;\n - CPU B, delete=true: netlink TIPC_NL_BEARER_DISABLE -\u003e bearer_disable()\n   -\u003e tipc_node_delete_links() -\u003e tipc_node_link_down(n, bearer_id, true)\n   -\u003e kfree(l).\n\nThe link is freed with plain kfree(), not kfree_rcu(), and for UDP bearers\ndisable_media() only schedules the asynchronous cleanup_bearer() work, so\nits synchronize_net() runs after the links are already gone.  An in-flight\nCPU A that has read l therefore dereferences freed memory once B frees it:\na use-after-free read in tipc_link_is_establishing(), and a use-after-free\nwrite via tipc_link_reset() on the establishing branch.\n\nThe following trace was captured on 7.2.0-rc5-00284-gaf39eb111ce6:\n\n  BUG: KASAN: slab-use-after-free in tipc_link_is_establishing (net/tipc/link.c:285)\n  Read of size 4 at addr ffff88802e2aa068 by task swapper/2/0\n   tipc_link_is_establishing (net/tipc/link.c:285)\n   tipc_node_link_down (net/tipc/node.c:1076)\n   tipc_node_timeout (net/tipc/node.c:843)\n  Allocated by task 9549:\n   tipc_link_create (net/tipc/link.c:490)\n   tipc_node_check_dest (net/tipc/node.c:1279)\n   tipc_disc_rcv (net/tipc/discover.c:252)\n   tipc_udp_recv (net/tipc/udp_media.c:389)\n  Freed by task 9549:\n   tipc_node_link_down (net/tipc/node.c:1084)\n   tipc_node_delete_links (net/tipc/node.c:1320)\n   bearer_disable (net/tipc/bearer.c:414)\n   __tipc_nl_bearer_disable (net/tipc/bearer.c:992)\n\nMove the le-\u003elink read inside tipc_node_write_lock(), so it is serialised\nagainst the kfree() in the delete path.  A racing teardown now either has\nnot run yet, and we see a valid link, or has already run, and we see NULL.",
  "id": "CVE-2026-74609",
  "modified": "2026-08-24T11:35:42.802383842Z",
  "published": "2026-08-22T15:31:56.054Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2be741ad565c610871a6a95062c12c39da7168fd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/47ba70891b10b2feb52462086b7fcd2ad75d3ce3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5558a8312452ddb21eff22b1cbd84302ad951944"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/69d209461c110388710e483a130caf051e4fd09a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a714d62513befef37f71f4ae89bb1fe173b65f2e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c3f2347a47754eac690967cfd82cb6d559817b07"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cba9ccb47e9fa4cc77692fb896cc5ab57a667882"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de017c22135f545ca4e65d1eada22887b64958eb"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74609.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74609"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "tipc: read le-\u003elink under the node lock in tipc_node_link_down()"
}