udp: Fix multiple wraparounds of sk->sk_rmem_alloc.

{
  "id": "029a3130a99bdabc7512b9716b01357a121e19ac05dbe0a99c59f1f06bc6e55e",
  "url": "https://osv.dev/vulnerability/CVE-2025-22059",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "udp: Fix multiple wraparounds of sk->sk_rmem_alloc.",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: udp: Fix multiple wraparounds of sk->sk_rmem_alloc. __udp_enqueue_schedule_skb() has the following condition: if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) goto drop; sk->sk_rcvbuf is initialised by net.core.rmem_default and later can be configured by SO_RCVBUF, which is limited by net.core.rmem_max, or SO_RCVBUFFORCE. If we set INT_MAX to sk->sk_rcvbuf, the condition is always false as sk->sk_rmem_alloc is also signed int. Then, the size of the incoming skb is added to sk->sk_rmem_alloc unconditionally. This results in integer overflow (possibly multiple times) on sk->sk_rmem_alloc and allows a single socket to have skb up to net.core.udp_mem[1]. For example, if we set a large value to udp_mem[1] and INT_MAX to sk->sk_rcvbuf and flood packets to the socket, we can see multiple overflows: # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 7956736 <-- (7956736 << 12) bytes > INT_MAX * 15 ^- PAGE_SHIFT # ss -uam State Recv-Q ... UNCONN -1757018048 ... <-- flipping the sign repeatedly skmem:(r2537949248,rb2147483646,t0,tb212992,f1984,w0,o0,bl0,d0) Previously, we had a boundary check for INT_MAX, which was removed by commit 6a1f12dd85a8 (\"udp: relax atomic operation on sk->sk_rmem_alloc\"). A complete fix would be to revert it and cap the right operand by INT_MAX: rmem = atomic_add_return(size, &sk->sk_rmem_alloc); if (rmem > min(size + (unsigned int)sk->sk_rcvbuf, INT_MAX)) goto uncharge_drop; but we do",
    "evidence": "osv:CVE-2025-22059",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.23",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.13.11",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.14.2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-22059",
      "aliases": [
        "CVE-2025-22059"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "6a1f12dd85a8b24f871dfcf467378660af9c064d"
                },
                {
                  "fixed": "94d5ad7b41122be33ebc2a6830fe710cba1ecd75"
                },
                {
                  "fixed": "1f529988efe9870db802cb79d01d8f473099b4d7"
                },
                {
                  "fixed": "7571aadd20289e9ea10ebfed0986f39ed8b3c16b"
                },
                {
                  "fixed": "5a465a0da13ee9fbd7d3cd0b2893309b0fe4b7e3"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-22059.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.10.0"
                },
                {
                  "fixed": "6.12.23"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.13.11"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.14.0"
                },
                {
                  "fixed": "6.14.2"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-22059.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:28.114107413Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1f529988efe9870db802cb79d01d8f473099b4d7",
        "https://git.kernel.org/stable/c/5a465a0da13ee9fbd7d3cd0b2893309b0fe4b7e3",
        "https://git.kernel.org/stable/c/7571aadd20289e9ea10ebfed0986f39ed8b3c16b",
        "https://git.kernel.org/stable/c/94d5ad7b41122be33ebc2a6830fe710cba1ecd75",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/22xxx/CVE-2025-22059.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-22059",
        "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/2025/22xxx/CVE-2025-22059.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-22059",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 494615,
  "published_at": "2025-04-16T14:12:15.505+00:00"
}