bpf, sockmap: Fix race between element replace and close()

{
  "id": "5e97da06caf6a348b6ac6e6d81d749109e99153aa908f45f0c099cf15f30da3d",
  "url": "https://osv.dev/vulnerability/CVE-2024-56664",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bpf, sockmap: Fix race between element replace and close()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix race between element replace and close() Element replace (with a socket different from the one stored) may race with socket's close() link popping & unlinking. __sock_map_delete() unconditionally unrefs the (wrong) element: // set map[0] = s0 map_update_elem(map, 0, s0) // drop fd of s0 close(s0) sock_map_close() lock_sock(sk) (s0!) sock_map_remove_links(sk) link = sk_psock_link_pop() sock_map_unlink(sk, link) sock_map_delete_from_link // replace map[0] with s1 map_update_elem(map, 0, s1) sock_map_update_elem (s1!) lock_sock(sk) sock_map_update_common psock = sk_psock(sk) spin_lock(&stab->lock) osk = stab->sks[idx] sock_map_add_link(..., &stab->sks[idx]) sock_map_unref(osk, &stab->sks[idx]) psock = sk_psock(osk) sk_psock_put(sk, psock) if (refcount_dec_and_test(&psock)) sk_psock_drop(sk, psock) spin_unlock(&stab->lock) unlock_sock(sk) __sock_map_delete spin_lock(&stab->lock) sk = *psk // s1 replaced s0; sk == s1 if (!sk_test || sk_test == sk) // sk_test (s0) != sk (s1); no branch sk = xchg(psk, NULL) if (sk) sock_map_unref(sk, psk) // unref s1; sks[idx] will dangle psock = sk_psock(sk) sk_psock_put(sk, psock) if (refcount_dec_and_test()) sk_psock_drop(sk, psock) spin_unlock(&stab->lock) release_sock(sk) Then close(map) enqueues bpf_map_free_deferred, which finally calls sock_map_free(). This results in some refcount_t warnings along with a KASAN splat [1]. Fix __sock_map_delete(), do not all",
    "evidence": "osv:CVE-2024-56664",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.236",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.180",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.125",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.67",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2024-56664",
      "aliases": [
        "CVE-2024-56664"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "fixed": "6deb9e85dc9a2ba4414b91c1b5b00b8415910890"
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                {
                  "fixed": "fdb2cd8957ac51f84c9e742ba866087944bb834b"
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                {
                  "fixed": "b79a0d1e9a374d1b376933a354c4fcd01fce0365"
                },
                {
                  "fixed": "b015f19fedd2e12283a8450dd0aefce49ec57015"
                },
                {
                  "fixed": "bf2318e288f636a882eea39f7e1015623629f168"
                },
                {
                  "fixed": "ed1fc5d76b81a4d681211333c026202cad4d5649"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-56664.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "4.20.0"
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            {
              "type": "ECOSYSTEM",
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-56664.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.161062669Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/6deb9e85dc9a2ba4414b91c1b5b00b8415910890",
        "https://git.kernel.org/stable/c/b015f19fedd2e12283a8450dd0aefce49ec57015",
        "https://git.kernel.org/stable/c/b79a0d1e9a374d1b376933a354c4fcd01fce0365",
        "https://git.kernel.org/stable/c/bf2318e288f636a882eea39f7e1015623629f168",
        "https://git.kernel.org/stable/c/ed1fc5d76b81a4d681211333c026202cad4d5649",
        "https://git.kernel.org/stable/c/fdb2cd8957ac51f84c9e742ba866087944bb834b",
        "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html",
        "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56664.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-56664",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56664.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-56664",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 498882,
  "published_at": "2024-12-27T15:06:26.276+00:00"
}