Vulnerability in Linux
CVE-2025-21954
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.
EPSS: 0.002 (8.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Linux — versions 65249feb6b3df9e17bab5911ee56fa7b0971e231, 6.12, 0
- Linux Linux_kernel — versions 6.14
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2025-21954?
- CVE-2025-21954 is a critical-severity vulnerability in Linux, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 9.8/10. Published 2025-04-01.
- How severe is CVE-2025-21954?
- Critical severity. CVSS v3 base score is 9.8 out of 10.