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GHSA-Q8RF-2MP5-5994

Vulnerability from github – Published: 2025-07-25 18:30 – Updated: 2026-05-12 15:30
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

netlink: Fix wraparounds of sk->sk_rmem_alloc.

Netlink has this pattern in some places

if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) atomic_add(skb->truesize, &sk->sk_rmem_alloc);

, which has the same problem fixed by commit 5a465a0da13e ("udp: Fix multiple wraparounds of sk->sk_rmem_alloc.").

For example, if we set INT_MAX to SO_RCVBUFFORCE, the condition is always false as the two operands are of int.

Then, a single socket can eat as many skb as possible until OOM happens, and we can see multiple wraparounds of sk->sk_rmem_alloc.

Let's fix it by using atomic_add_return() and comparing the two variables as unsigned int.

Before: [root@fedora ~]# ss -f netlink Recv-Q Send-Q Local Address:Port Peer Address:Port -1668710080 0 rtnl:nl_wraparound/293 *

After: [root@fedora ~]# ss -f netlink Recv-Q Send-Q Local Address:Port Peer Address:Port 2147483072 0 rtnl:nl_wraparound/290 * ^ `--- INT_MAX - 576

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2025-38465"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-401"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-07-25T16:15:32Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetlink: Fix wraparounds of sk-\u003esk_rmem_alloc.\n\nNetlink has this pattern in some places\n\n  if (atomic_read(\u0026sk-\u003esk_rmem_alloc) \u003e sk-\u003esk_rcvbuf)\n  \tatomic_add(skb-\u003etruesize, \u0026sk-\u003esk_rmem_alloc);\n\n, which has the same problem fixed by commit 5a465a0da13e (\"udp:\nFix multiple wraparounds of sk-\u003esk_rmem_alloc.\").\n\nFor example, if we set INT_MAX to SO_RCVBUFFORCE, the condition\nis always false as the two operands are of int.\n\nThen, a single socket can eat as many skb as possible until OOM\nhappens, and we can see multiple wraparounds of sk-\u003esk_rmem_alloc.\n\nLet\u0027s fix it by using atomic_add_return() and comparing the two\nvariables as unsigned int.\n\nBefore:\n  [root@fedora ~]# ss -f netlink\n  Recv-Q      Send-Q Local Address:Port                Peer Address:Port\n  -1668710080 0               rtnl:nl_wraparound/293               *\n\nAfter:\n  [root@fedora ~]# ss -f netlink\n  Recv-Q     Send-Q Local Address:Port                Peer Address:Port\n  2147483072 0               rtnl:nl_wraparound/290               *\n  ^\n  `--- INT_MAX - 576",
  "id": "GHSA-q8rf-2mp5-5994",
  "modified": "2026-05-12T15:30:58Z",
  "published": "2025-07-25T18:30:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38465"
    },
    {
      "type": "WEB",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4b8e18af7bea92f8b7fb92d40aeae729209db250"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55baecb9eb90238f60a8350660d6762046ebd3bd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/76602d8e13864524382b0687dc32cd8f19164d5a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9da025150b7c14a8390fc06aea314c0a4011e82c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ae8f160e7eb24240a2a79fc4c815c6a0d4ee16cc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c4ceaac5c5ba0b992ee1dc88e2a02421549e5c98"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd7ff61bfffd7000143c42bbffb85eeb792466d6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fd69af06101090eaa60b3d216ae715f9c0a58e5b"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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