Kirill A. Shutemov

Name of the Vulnerable Software and Affected Versions: Linux kernel (affected versions not specified) Description: The Linux kernel has a weakness related to transient execution in Linear Address Masking (LAM) as described in the SLAM paper. This weakness may be exploitable unless Linear Address Space Separation (LASS) is enabled. Currently, no processors in the market support LAM, so nobody is affected by this issue. Recommendations: At the moment, there is no information about a newer version that contains a fix for this vulnerability.

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.

The issue concerns the mishandling of anonymous pages in the Linux kernel, allowing local users to gain privileges or cause a denial of service, specifically through page tainting, by using a crafted application that triggers writing to page zero.