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
"func_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 ("function_graph: Add READ_ONCE() when accessing fgraph_array[]").

Classification

CVE ID: CVE-2024-57934

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 11.7% (scored less or equal to compared to others)

EPSS Date: 2025-02-19 (when was this score calculated)

References

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

Timeline