Access of Uninitialized Pointer Affecting kernel-uki-virt package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.19% (9th percentile)

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  • Snyk IDSNYK-CENTOS10-KERNELUKIVIRT-19246267
  • published25 Aug 2026
  • disclosed22 Aug 2026

Introduced: 22 Aug 2026

NewCVE-2026-74667  (opens in a new tab)
CWE-824  (opens in a new tab)

How to fix?

There is no fixed version for Centos:10 kernel-uki-virt.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-uki-virt package and not the kernel-uki-virt 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/packet: reset the MAC header on the packet-socket transmit path

packet_parse_headers() resets the MAC header only for a SOCK_RAW frame whose socket did not bind a protocol. A protocol-bound SOCK_RAW socket, any SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave skb->mac_header unset here.

For frames sent via __dev_queue_xmit() this is harmless: it resets the MAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS path uses dev_direct_xmit(), which does not, so the frame reaches ndo_start_xmit() with the MAC header unset. A driver that reads eth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an out-of-bounds access ~64 KiB past the head -- the same class fixed for one consumer in commit f5089008f90c ("macsec: do not read an unset MAC header in macsec_encrypt()").

packet_parse_headers() runs only on the transmit path, where skb->data points at the start of the L2 header for every packet-socket type regardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied header and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC header unconditionally, mirroring __dev_queue_xmit(), so the frame is anchored on the bypass path too.

Found by 0sec (https://0sec.ai) using automated source analysis; verified against source and matched to the macsec KASAN report in f5089008f90c. Compile-tested.

CVSS Base Scores

version 3.1