{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "75eb6af7acdf566c68d61e98e67ee2f235201c02"
            },
            {
              "fixed": "79cd550f8c884523b604fbfa43eb02def74d6224"
            },
            {
              "fixed": "7a65b41b657b71d5a77861f47dd13eb4bc8e10d0"
            },
            {
              "fixed": "5b0427ba582d143a364301f825f4e32272f06d2d"
            },
            {
              "fixed": "d49f6d098ed48775b9d27a9f9c5c220fdf76f102"
            },
            {
              "fixed": "46bc86c833956219bbfd246c1ffd832a479c5199"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.5.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.97"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.40"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72317.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: pin upper rpc_clnt across the TLS connect_worker\n\nThe TLS connect path has a use-after-free: nothing pins the\nupper rpc_clnt across the delayed connect_worker. xs_connect()\nstores task-\u003etk_client in sock_xprt::clnt as a raw pointer\nand queues the worker; for TLS-secured transports that worker\nis xs_tcp_tls_setup_socket(), which reads several fields out\nof the saved pointer (cl_timeout, cl_program, cl_prog,\ncl_vers, cl_cred, cl_stats) to construct the args for the\ninner handshake rpc_clnt.\n\nThe xprt does not reference the rpc_clnt; the rpc_clnt\nreferences the xprt. xs_destroy() does cancel the\nconnect_worker, but it runs only when the xprt's refcount\ndrops to zero, which cannot happen until the rpc_clnt\nreleases its cl_xprt reference in rpc_free_client_work().\nWhen a TLS handshake fails fatally (for example, an mTLS\nmount whose client cert does not match the server), the\nconnecting task is woken with -EACCES and exits, the mount\ncaller invokes rpc_shutdown_client(), and the upper rpc_clnt\nis freed before the queued connect_worker fires.\nxs_tcp_tls_setup_socket() then dereferences the freed clnt,\nproducing the refcount_t underflow Michael Nemanov reported.\n\nTake a reference on the upper rpc_clnt in xs_connect() for\nTLS transports via a new rpc_hold_client() helper, and drop\nit in the connect_worker's exit path with rpc_release_client().\nThe xprt_lock_connect() / xprt_unlock_connect() pairing\nalready serialises xs_connect() with xs_tcp_tls_setup_socket(),\nso the take and release are balanced one-for-one.\n\nThe non-TLS connect worker (xs_tcp_setup_socket) never reads\nsock_xprt::clnt, so leave that path alone and avoid the\nclnt-holds-xprt-holds-clnt cycle that would otherwise prevent\nxprt destruction.",
  "id": "CVE-2026-72317",
  "modified": "2026-08-18T03:31:11.677095946Z",
  "published": "2026-08-15T05:55:31.022Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/46bc86c833956219bbfd246c1ffd832a479c5199"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5b0427ba582d143a364301f825f4e32272f06d2d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/79cd550f8c884523b604fbfa43eb02def74d6224"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7a65b41b657b71d5a77861f47dd13eb4bc8e10d0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d49f6d098ed48775b9d27a9f9c5c220fdf76f102"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72317.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72317"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "SUNRPC: pin upper rpc_clnt across the TLS connect_worker"
}