GHSA-MMVG-F8X9-HVR5
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-24 15:32In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: bind uarg before filling zerocopy skb
virtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg before entering the send loop, but virtio_transport_alloc_skb() still fills the skb before it inherits that uarg. When fixed-buffer vectored zerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach managed frags and return -EMSGSIZE. The rollback path call kfree_skb() to free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so skb_release_data() falls through to ordinary frag unref.
Pass the uarg into virtio_transport_alloc_skb() and bind it immediately before virtio_transport_fill_skb(). This keeps control or no-payload skbs untouched while ensuring success and rollback share one lifetime rule.
{
"affected": [],
"aliases": [
"CVE-2026-63970"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:16Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: bind uarg before filling zerocopy skb\n\nvirtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg\nbefore entering the send loop, but virtio_transport_alloc_skb() still\nfills the skb before it inherits that uarg. When fixed-buffer vectored\nzerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach\nmanaged frags and return -EMSGSIZE. The rollback path call kfree_skb()\nto free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so\nskb_release_data() falls through to ordinary frag unref.\n\nPass the uarg into virtio_transport_alloc_skb() and bind it immediately\nbefore virtio_transport_fill_skb(). This keeps control or no-payload skbs\nuntouched while ensuring success and rollback share one lifetime rule.",
"id": "GHSA-mmvg-f8x9-hvr5",
"modified": "2026-07-24T15:32:43Z",
"published": "2026-07-19T18:31:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63970"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1e584c304cfb94a759417130b1fc6d30b30c4cce"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5d317573f1d48e76cce5fb6250452b6e4102e0fb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/72194f65050958e4c8e069adb6c5d89ef81ca197"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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