CVE-2024-36911

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.6.37

Description In CoCo VMs, it is possible for the untrusted host to cause set memory encrypted() or set memory decrypted() to fail, resulting in shared memory. Callers need to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. The netvsc driver could free decrypted/shared pages if set memory decrypted() fails. Checking the decrypted field in the gpadl can decide whether to free the memory.

Recommendations To resolve the issue, update to Linux kernel version 6.6.37 or later. As a temporary workaround, consider checking the decrypted field in the gpadl to decide whether to free the memory, and handle errors from set memory encrypted() and set memory decrypted() to avoid returning decrypted (shared) memory to the page allocator.