{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "9ab4807c84a4aacfc9b4f79cc81254035e0ec361"
            },
            {
              "fixed": "f48341830e4202db3fe884b819b2db6740f0537d"
            },
            {
              "fixed": "bb32e9a6a9a9f99eeda16c4efe443400f3e43892"
            },
            {
              "fixed": "b2a0b55bf613bd3e81ed26a847b0f6b8e6b7f804"
            },
            {
              "fixed": "9fe5eebb664ecdba88f3fde18062d94b1d1c465f"
            },
            {
              "fixed": "6c290915a03fc8228b473641025cf762b256dbd2"
            },
            {
              "fixed": "efc33b5102ff859bacd390a5f30112d8e0c084c0"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.19.0"
            },
            {
              "fixed": "6.1.187"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.154"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.106"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.47"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80784.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: fix memory leak from alloc-during-teardown race\n\nmptcp_pm_destroy() empties msk-\u003epm.anno_list and\nmsk-\u003epm.userspace_pm_local_addr_list under msk-\u003epm.lock during socket\nteardown, dropping the lock between the two.\n\nA concurrent userspace PM genl ANNOUNCE on the same msk holds a sock\nreference via mptcp_token_get_sock() and, in\nmptcp_pm_nl_announce_doit(), calls\nmptcp_userspace_pm_append_new_local_addr() and\nmptcp_pm_announced_alloc(). Both take msk-\u003epm.lock briefly to add to\ntheir respective lists. Because the genl handler holds a sock reference,\nmptcp_pm_destroy() may run on the same msk via mptcp_disconnect(), which\ninvokes mptcp_destroy_common() without dropping the sock refcount,\nbefore the handler completes.\n\nIf the lock acquisitions interleave such that mptcp_pm_destroy() empties\na list first, the later alloc adds its entry to a list head that nothing\nelse iterates for this msk, and the entry leaks. kmemleak reports both\nmptcp_pm_add_addr objects (from mptcp_pm_announced_alloc()) and\nmptcp_pm_addr_entry objects (from\nmptcp_userspace_pm_append_new_local_addr()) under sustained concurrent\nANNOUNCE + close load against the userspace PM.\n\nAdd an MPTCP_PM_DESTROYING bit in msk-\u003epm.status, set by\nmptcp_pm_destroy() under pm.lock before the lists are emptied and\nchecked under pm.lock by the alloc paths. Either the alloc takes pm.lock\nfirst, in which case its entry is on the list when mptcp_pm_destroy()\nfrees it; or mptcp_pm_destroy() takes pm.lock first, in which case the\nlater alloc observes the bit and refuses.\n\nFound by an MPTCP protocol-flow harness extending BRF (arXiv:2305.08782).",
  "id": "CVE-2026-80784",
  "modified": "2026-09-06T03:30:43.831719221Z",
  "published": "2026-09-04T15:12:56.125Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6c290915a03fc8228b473641025cf762b256dbd2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9fe5eebb664ecdba88f3fde18062d94b1d1c465f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b2a0b55bf613bd3e81ed26a847b0f6b8e6b7f804"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bb32e9a6a9a9f99eeda16c4efe443400f3e43892"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/efc33b5102ff859bacd390a5f30112d8e0c084c0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f48341830e4202db3fe884b819b2db6740f0537d"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80784.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80784"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "mptcp: pm: fix memory leak from alloc-during-teardown race"
}