CVE-2025-21954

Source
https://nvd.nist.gov/vuln/detail/CVE-2025-21954
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-21954.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-21954
Downstream
Published
2025-04-01T16:15:26Z
Modified
2025-08-09T20:01:27Z
Summary
[none]
Details

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 ipproto \ tcp srcip 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.

References

Affected packages

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.12.20-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:14 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.12.20-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}