Linux vulnerability

What happened

In 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 versions

Linux: 581512a6dc939ef122e49336626ae159f3b8a345 through before 72194f65050958e4c8e069adb6c5d89ef81ca197 (git); 581512a6dc939ef122e49336626ae159f3b8a345 through before b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d (git); 581512a6dc939ef122e49336626ae159f3b8a345 through before 5d317573f1d48e76cce5fb6250452b6e4102e0fb (git); 581512a6dc939ef122e49336626ae159f3b8a345 through before 1e584c304cfb94a759417130b1fc6d30b30c4cce (git); 6.7 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.