CVE-2025-21670

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.6.73/6.12.10

Description The issue is related to a null pointer dereference in the Linux kernel's vsock/bpf module. This can occur when a socket has a null transport, for example, after a failed connect() call. The error can cause a kernel crash, leading to a denial of service. The vsock bpf recvmsg() function needs to check the vsk->transport especially for connected sockets (stream/seqpacket) to prevent this issue.

Recommendations To resolve the issue, update the Linux kernel to a version newer than 6.6.73/6.12.10. As a temporary workaround, consider restricting access to the vsock bpf recvmsg() function, especially for connected sockets, until a patch is available. Additionally, ensure that the vsk->transport is properly checked in the vsock bpf recvmsg() function to prevent null pointer dereferences.