GHSA-6C34-77J2-7G8C

Vulnerability from github – Published: 2026-07-27 21:31 – Updated: 2026-07-27 21:31
VLAI
Details

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

virtio-net: fix len check in receive_big()

receive_big() bounds the device-announced length by (big_packets_num_skbfrags + 1) * PAGE_SIZE. That is still too loose: add_recvbuf_big() sets sg[1] to start at offset sizeof(struct padded_vnet_hdr) into the first page, so the chain actually carries hdr_len + (PAGE_SIZE - sizeof(padded_vnet_hdr)) + big_packets_num_skbfrags * PAGE_SIZE bytes -- 20 bytes less than the check allows for the common hdr_len == 12 case.

A malicious virtio backend can announce a len in that gap. page_to_skb() then walks one frag past the page chain, storing a NULL page->private into skb_shinfo()->frags[MAX_SKB_FRAGS], which is both an out-of-bounds write past the static frag array and a NULL frag handed up the rx path.

Bound len by the size add_recvbuf_big() actually advertised.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64552"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-27T21:17:08Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio-net: fix len check in receive_big()\n\nreceive_big() bounds the device-announced length by\n(big_packets_num_skbfrags + 1) * PAGE_SIZE.  That is still too loose:\nadd_recvbuf_big() sets sg[1] to start at offset\nsizeof(struct padded_vnet_hdr) into the first page, so the chain\nactually carries hdr_len + (PAGE_SIZE - sizeof(padded_vnet_hdr)) +\nbig_packets_num_skbfrags * PAGE_SIZE bytes -- 20 bytes less than the\ncheck allows for the common hdr_len == 12 case.\n\nA malicious virtio backend can announce a len in that gap.  page_to_skb()\nthen walks one frag past the page chain, storing a NULL page-\u003eprivate\ninto skb_shinfo()-\u003efrags[MAX_SKB_FRAGS], which is both an out-of-bounds\nwrite past the static frag array and a NULL frag handed up the rx path.\n\nBound len by the size add_recvbuf_big() actually advertised.",
  "id": "GHSA-6c34-77j2-7g8c",
  "modified": "2026-07-27T21:31:27Z",
  "published": "2026-07-27T21:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64552"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/38e94d63e29f4a5c6eae87ee2c02101aaa321502"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9e5ad06ea826322ce8c58b4a68442a96f600c3c4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c7fc9adf4e006155f7f2aeda052fbcde25cdcc49"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e6b8463b7d791f3886d7584259d6e9f06a69f12e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f9451d0fd5ba635dcabb49bfe456a6db734a8986"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fbeb65154583879d556ea94cb2f15888e9470f3d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}



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