CVE-2025-21884

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue concerns the lifetime of kernel sockets in the Linux kernel. When kernel sockets are dismantled during the exit of pernet operations, their freeing can be delayed due to any tx packets still held in qdisc or device queues. This triggers a warning from ref tracker dir exit. To fix this, a reference on net->passive is ensured for kernel sockets. A helper, sk net refcnt upgrade, is added for when a kernel socket is converted to a refcounted one.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.