FKIE_CVE-2026-31472

Vulnerability from fkie_nvd - Published: 2026-04-22 14:16 - Updated: 2026-04-23 16:17
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: validate inner IPv4 header length in IPTFS payload Add validation of the inner IPv4 packet tot_len and ihl fields parsed from decrypted IPTFS payloads in __input_process_payload(). A crafted ESP packet containing an inner IPv4 header with tot_len=0 causes an infinite loop: iplen=0 leads to capturelen=min(0, remaining)=0, so the data offset never advances and the while(data < tail) loop never terminates, spinning forever in softirq context. Reject inner IPv4 packets where tot_len < ihl*4 or ihl*4 < sizeof(struct iphdr), which catches both the tot_len=0 case and malformed ihl values. The normal IP stack performs this validation in ip_rcv_core(), but IPTFS extracts and processes inner packets before they reach that layer.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0d10393d5eac33cbd92f7a41fddca12c41d3cb7e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3db7d4f777a00164582061ccaa99569cd85011a3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/de6d8e8ce5187f7402c9859b443355e7120c5f09
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: validate inner IPv4 header length in IPTFS payload\n\nAdd validation of the inner IPv4 packet tot_len and ihl fields parsed\nfrom decrypted IPTFS payloads in __input_process_payload(). A crafted\nESP packet containing an inner IPv4 header with tot_len=0 causes an\ninfinite loop: iplen=0 leads to capturelen=min(0, remaining)=0, so the\ndata offset never advances and the while(data \u003c tail) loop never\nterminates, spinning forever in softirq context.\n\nReject inner IPv4 packets where tot_len \u003c ihl*4 or ihl*4 \u003c sizeof(struct\niphdr), which catches both the tot_len=0 case and malformed ihl values.\nThe normal IP stack performs this validation in ip_rcv_core(), but IPTFS\nextracts and processes inner packets before they reach that layer."
    }
  ],
  "id": "CVE-2026-31472",
  "lastModified": "2026-04-23T16:17:41.280",
  "metrics": {},
  "published": "2026-04-22T14:16:43.740",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0d10393d5eac33cbd92f7a41fddca12c41d3cb7e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3db7d4f777a00164582061ccaa99569cd85011a3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/de6d8e8ce5187f7402c9859b443355e7120c5f09"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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