CVE-2025-21954

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux65249feb6b3df9e17bab5911ee56fa7b0971e231 < 454825019d2f0c59e5174ece9e713f45ad80beffaffected
LinuxLinux65249feb6b3df9e17bab5911ee56fa7b0971e231 < 1c17c8ced25c5fbe424c7ad7ea11d33014a986b1affected
LinuxLinux65249feb6b3df9e17bab5911ee56fa7b0971e231 < f3600c867c99a2cc8038680ecf211089c50e7971affected
LinuxLinux6.12affected
LinuxLinux0 < 6.12unaffected
LinuxLinux6.12.20 <= 6.12.*unaffected
LinuxLinux6.13.8 <= 6.13.*unaffected
LinuxLinux6.14 <= *unaffected

Weaknesses

References