CVE-2026-74684

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: tap: set skb-&gt;dev before parsing virtio net header in tap_get_user_xdp()<br /> <br /> The commit 4f61f133f354 ("net: tap: NULL pointer derefence in<br /> dev_parse_header_protocol when skb-&gt;dev is null") fixed a crash in<br /> tap_get_user() by assigning skb-&gt;dev before calling tun_vnet_hdr_to_skb().<br /> This is required because virtio_net_hdr_to_skb() may invoke<br /> dev_parse_header_protocol(), which dereferences skb-&gt;dev. Without the<br /> assignment, a NULL pointer dereference can occur.<br /> <br /> However, tap_get_user_xdp() still parses the virtio-net header before<br /> assigning skb-&gt;dev. When the vhost TX path passes an XDP buffer containing<br /> a GSO virtio-net header but the protocol is set to zero on purpose,<br /> tun_vnet_hdr_to_skb() can reach dev_parse_header_protocol() while skb-&gt;dev<br /> is still NULL, resulting in a crash.<br /> <br /> Fix this by looking up the tap device and assigning skb-&gt;dev before calling<br /> tun_vnet_hdr_to_skb(), matching the ordering already used in<br /> tap_get_user(). Preserve the existing RCU read-side critical section across<br /> dev_queue_xmit().