Vulnerability 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 Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.12, < 6.12.20 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/1c17c8ced25c5fbe424c7ad7ea11d33014a986b1Patch
- https://git.kernel.org/stable/c/454825019d2f0c59e5174ece9e713f45ad80beffPatch
- https://git.kernel.org/stable/c/f3600c867c99a2cc8038680ecf211089c50e7971Patch
FAQ
What is CVE-2025-21954?
CVE-2025-21954 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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...
How severe is CVE-2025-21954?
CVE-2025-21954 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2025-21954?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.