CVE Catalog

CVE-2026-74684

HighCVSS 7.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel, the net: tap driver has a vulnerability where in tap_get_user_xdp() the virtio-net header is parsed before assigning skb->dev. When the vhost TX path passes an XDP buffer with a GSO virtio-net header and protocol set to zero, dev_parse_header_protocol() can be called with skb->dev NULL, leading to a crash.

Risk Assessment

The risk includes system crash (NULL pointer dereference) in the packet processing path, which could lead to unavailability of network services.

Recommendation

Apply the Linux kernel patch that assigns skb->dev before calling tun_vnet_hdr_to_skb(), matching the ordering in tap_get_user().

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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().

Vulnerability data from NVD (NIST) · CISA KEV · EPSS