Description

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

tracing: Verify event formats that have "%*p.."

The trace event verifier checks the formats of trace events to make sure
that they do not point at memory that is not in the trace event itself or
in data that will never be freed. If an event references data that was
allocated when the event triggered and that same data is freed before the
event is read, then the kernel can crash by reading freed memory.

The verifier runs at boot up (or module load) and scans the print formats
of the events and checks their arguments to make sure that dereferenced
pointers are safe. If the format uses "%*p.." the verifier will ignore it,
and that could be dangerous. Cover this case as well.

Also add to the sample code a use case of "%*pbl".

Classification

CVE ID: CVE-2025-37938

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 7.59% (scored less or equal to compared to others)

EPSS Date: 2025-06-18 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-37938
https://git.kernel.org/stable/c/6854c87ac823181c810f8c07489ba543260c0023
https://git.kernel.org/stable/c/4d11fac941d83509be4e6a21038281d6d96da50c
https://git.kernel.org/stable/c/03127354027508d076073b020d3070990fd6a958
https://git.kernel.org/stable/c/04b80d45ecfaf780981d6582899e3ab205e4aa08
https://git.kernel.org/stable/c/c7204fd1758c0caf1938e8a59809a1fdf28a8114
https://git.kernel.org/stable/c/ea8d7647f9ddf1f81e2027ed305299797299aa03

Timeline