CVE-2022-49886

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A vulnerability in the Linux kernel has been resolved, related to the x86/tdx component. The issue occurs when the kernel accesses "private" memory, which includes all normal kernel memory, such as kernel stacks and kernel text. The TDX hardware can generate a virtualization exception (#VE) on any access to private memory. However, this exception can be disabled using the ATTR SEPT VE DISABLE attribute. If this attribute is not set, the kernel will panic. The guest has no way to set this attribute but can check it. The kernel has an early #VE handler during boot, but it will also panic if it sees any other #VE, such as one generated by a private memory access.

Recommendations Ensure ATTR SEPT VE DISABLE is set in early boot. If ATTR SEPT VE DISABLE is not set, use panic() to prevent the kernel from running with this attribute clear. As a temporary workaround, consider disabling the early #VE handler until a patch is available. Restrict access to private memory to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.