NULL Pointer Dereference Affecting kernel-64k-core package, versions *


Severity

Recommended
medium

Based on CentOS security rating.

Threat Intelligence

EPSS
0.17% (7th percentile)

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  • Snyk IDSNYK-CENTOS10-KERNEL64KCORE-19249725
  • published25 Aug 2026
  • disclosed22 Aug 2026

Introduced: 22 Aug 2026

NewCVE-2026-74684  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for Centos:10 kernel-64k-core.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-64k-core package and not the kernel-64k-core package as distributed by Centos. See How to fix? for Centos:10 relevant fixed versions and status.

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().

CVSS Base Scores

version 3.1