CVE-2026-74668

Updated on 22 Aug 2026

Severity

7.8 High severity

Details

CVSS score
7.8
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

packet: use consistent hard_header_len in TX_RING send path

tpacket_snd() reads dev->hard_header_len independently for skb allocation and header construction in tpacket_fill_skb(). Concurrent netdevice reconfiguration can therefore make the reserved headroom smaller than the amount later pushed, or make copylen - hard_header_len negative.

Snapshot hard_header_len once before processing ring frames and use it for the frame limit, headroom allocation, copy length, and skb construction. Pass the snapshot to tpacket_fill_skb().

The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.

Details

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 12 Planned
Debian 13 Planned