CVE-2024-57934 Information

Description

In the Linux kernel the following vulnerability has been resolved:

fgraph: Add READ_ONCE() when accessing fgraph_array[]

In __ftrace_return_to_handler() a loop iterates over the fgraph_array[] elements which are fgraph_ops. The loop checks if an element is a fgraph_stub to prevent using a fgraph_stub afterward.

However if the compiler reloads fgraph_array[] after this check it might race with an update to fgraph_array[] that introduces a fgraph_stub. This could result in the stub being processed but the stub contains a null unc_hash\ field leading to a NULL pointer dereference.

To ensure that the gops compared against the fgraph_stub matches the gops processed later add a READ_ONCE(). A similar patch appears in commit 63a8dfb (unction_graph: Add READ_ONCE() when accessing fgraph_array[]).

Reference

https://git.kernel.org/stable/c/b68b2a3fbacc7be720ef589d489bcacdd05c6d38 https://git.kernel.org/stable/c/d65474033740ded0a4fe9a097fce72328655b41d