In the Linux kernel, the following vulnerability has been resolved: virt: sev-guest: Explicitly leak pages in unknown state When set_memory_{encrypted,decrypted}() fail, the user cannot know at which point the function failed, meaning that the pages are left in an unknown state from the point of view of the caller. Since the pages may be left in an unencrypted state, they are not suitable for general use, and cannot be returned safely to the buddy allocator. Avoid the issue by never freeing the pages, and then do the proper accounting by calling snp_leak_pages().
https://git.kernel.org/stable/c/fd948c3f96b18ff9ba7d3e8eae13d196593e1aaf
https://git.kernel.org/stable/c/bee400ad4f4259c9c0758e4f1960a1eed6f6f9f0
https://git.kernel.org/stable/c/3d0cd0065deeb054b4b29236432e851806b7cc81