עברית

Vulnerability Intelligence

CVE-2025-21954

Medium 5.5

Published
Last modified
NVD status
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: netmem: prevent TX of unreadable skbs Currently on stable trees we have support for netmem/devmem RX but not TX. It is not safe to forward/redirect an RX unreadable netmem packet into the device's TX path, as the device may call dma-mapping APIs on dma addrs that should not be passed to it. Fix this by preventing the xmit of unreadable skbs. Tested by configuring tc redirect: sudo tc qdisc add dev eth1 ingress sudo tc filter add dev eth1 ingress protocol ip prio 1 flower ip_proto \ tcp src_ip 192.168.1.12 action mirred egress redirect dev eth1 Before, I see unreadable skbs in the driver's TX path passed to dma mapping APIs. After, I don't see unreadable skbs in the driver's TX path passed to dma mapping APIs.

Affected products

linux: linux kernel

References3

Metrics

CVSS 3.1
5.5 MEDIUM Score source: NVD CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS — exploit probability
1% percentile: 43 · as of 7 November 2026
CWE
CWE-401

Could this be exploited in your environment?

A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.