virt: tdx-guest: Just leak decrypted memory on unrecoverable errors

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: virt: tdx-guest: Just leak decrypted memory on unrecoverable errors In CoCo VMs it is possible for the untrusted host to cause set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. Leak the decrypted memory when set_memory_decrypted() fails, and don't need to print an error since set_memory_decrypted() will call WARN_ONCE().

References

• https://git.kernel.org/stable/c/1429ae7b7d4759a1e362456b8911c701bae655b4
• https://git.kernel.org/stable/c/27834971f616c5e154423c578fa95e0444444ce1