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CVE-2025-21954

Linux Kernel vulnerability

9.8 CRITICALEPSS 0.50%
  1. Published1 Apr 2025

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Kernel≥ 6.12 < 6.12.20 · ≥ 6.13 < 6.13.8 · 6.14

Remediation

Fixed in
Linux Kernel≥ 6.12.20

References

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Frequently asked

Is CVE-2025-21954 being actively exploited?

CVE-2025-21954 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.50%.

How severe is CVE-2025-21954?

CVE-2025-21954 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.50% probability of exploitation.

Which products are affected by CVE-2025-21954?

Affected products include Linux Kernel.

How do I fix CVE-2025-21954?

Upgrade affected software to a fixed version, for example Linux Kernel 6.12.20 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.