{"schema_version":"1.9.0","id":"CVE-2026-63970","published":"2026-07-19T14:55:57.067Z","modified":"2026-08-12T03:51:35.223551578Z","summary":"vsock/virtio: bind uarg before filling zerocopy skb","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.","affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"581512a6dc939ef122e49336626ae159f3b8a345"},{"fixed":"72194f65050958e4c8e069adb6c5d89ef81ca197"},{"fixed":"b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d"},{"fixed":"5d317573f1d48e76cce5fb6250452b6e4102e0fb"},{"fixed":"1e584c304cfb94a759417130b1fc6d30b30c4cce"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63970.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.35"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63970.json"}}],"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63970.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63970"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63970.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}