CVE-2022-50579

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

arm64: ftrace: fix module PLTs with mcount

Li Huafei reports that mcount-based ftrace with module PLTs was broken

by commit:

a6253579977e4c6f ("arm64: ftrace: consistently handle PLTs.")

When a module PLTs are used and a module is loaded sufficiently far away

from the kernel, we'll create PLTs for any branches which are

out-of-range. These are separate from the special ftrace trampoline

PLTs, which the module PLT code doesn't directly manipulate.

When mcount is in use this is a problem, as each mcount callsite in a

module will be initialized to point to a module PLT, but since commit

a6253579977e4c6f ftrace_make_nop() will assume that the callsite has

been initialized to point to the special ftrace trampoline PLT, and

ftrace_find_callable_addr() rejects other cases.

This means that when ftrace tries to initialize a callsite via

ftrace_make_nop(), the call to ftrace_find_callable_addr() will find

that the `_mcou

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References