CVE-2025-38052

A vulnerability was found in the Linux kernel's management of network namespaces. By manipulating the lifecycle of network namespaces, an attacker could exploit this vulnerability to cause a system crash or leak sensitive system memory. Exploitation of this vulnerability requires that a user has access to the system and the ability to create or destroy network namespaces. This typically requires administrative privileges, but could be exposed to an unprivileged user who has control over container lifecycles or a user who has administrative privileges within a container.

A slab-use-after-free vulnerability exists in the TIPC crypto subsystem in the Linux kernel. The bug is triggered when a network namespace is deleted while an asynchronous crypto operation is still pending, resulting in access to freed memory from a delayed worker context. The vulnerability requires local privileges to create and manipulate network namespaces and configure TIPC crypto bearers, which justifies the use of PR:L. Despite this, the impact on system memory and stability is significant due to the asynchronous nature of the cryptographic operation. Although not directly reachable from an unprivileged user context, this issue can be exploited by a local attacker with limited privileges, for example, in a container, to crash the kernel or perform arbitrary memory access via crafted namespace lifecycle manipulation.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation of this issue requires restricting access to the ability to create, modify, or destroy network namespaces. By default, this ability is restricted to privileged users. However, that restriction is only applicable to the host system itself and not to containerized applications. Administrators of container hosts should ensure that only trusted accounts can run containers.