SB20260816239 - Always-Incorrect Control Flow Implementation in Linux kernel core

Description

This security bulletin contains information about 1 vulnerability.

1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-74476)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper handling of non-linear skb fragment metadata in veth_convert_skb_to_xdp_buff() when processing frag_list skbs before exposing them to XDP. A local user can trigger processing of a crafted non-linear skb with frag_list data to cause a denial of service.

The issue can lead to a crash in memcpy() from __xsk_rcv() in AF_XDP copy mode.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5c1c15c540fc45820ce3033c319151ec891bc10a
• https://git.kernel.org/stable/c/b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb
• https://git.kernel.org/stable/c/d0d6415963040c401e7a7e4e482a698ba52448cb
• https://git.kernel.org/stable/c/f9c1fff857e93be709c8b52ed1a643f37bd82c66