CVE-2026-74684
Açıklama (NVD)
In the Linux kernel, the following vulnerability has been resolved: net: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp() The commit 4f61f133f354 ("net: tap: NULL pointer derefence in dev_parse_header_protocol when skb->dev is null") fixed a crash in tap_get_user() by assigning skb->dev before calling tun_vnet_hdr_to_skb(). This is required because virtio_net_hdr_to_skb() may invoke dev_parse_header_protocol(), which dereferences skb->dev. Without the assignment, a NULL pointer dereference can occur. However, tap_get_user_xdp() still parses the virtio-net header before assigning skb->dev. When the vhost TX path passes an XDP buffer containing a GSO virtio-net header but the protocol is set to zero on purpose, tun_vnet_hdr_to_skb() can reach dev_parse_header_protocol() while skb->dev is still NULL, resulting in a crash. Fix this by looking up the tap device and assigning skb->dev before calling tun_vnet_hdr_to_skb(), matching the ordering already used in tap_get_user(). Preserve the existing RCU read-side critical section across dev_queue_xmit().
Yayın: 22.08.2026 · Son değişiklik: 30.10.2026
CVSS 3.1 metrikleri
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
| Saldırı vektörü | Yerel |
| Karmaşıklık | Düşük |
| Gereken yetki | Yok |
| Kullanıcı etkileşimi | Gerekmez |
| Kapsam | Değişir |
| Gizlilik | Yok |
| Bütünlük | Yok |
| Erişilebilirlik | Yüksek |
Hesaplanan temel puan: 7.1. CVSS hesaplayıcıda incele
Referanslar
- https://git.kernel.org/stable/c/15583b07fd691a844fbf7b3ad612cdc9e9a657c0
- https://git.kernel.org/stable/c/164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b
- https://git.kernel.org/stable/c/1d022885f3e6e0e238815391a4afaf3a4fb0a442
- https://git.kernel.org/stable/c/3874892dd27d5387aa9a06f58d9060f18f351d24
- https://git.kernel.org/stable/c/61dd022c55c7307ec119e5672cb141cccbecf3b1
- https://git.kernel.org/stable/c/8b444b126cd8e4473e652f529753ed4dd1360a9c