CVE-2025-22003

/// Technical description

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

can: ucan: fix out of bound read in strscpy() source

Commit 7fdaf8966aae ("can: ucan: use strscpy() to instead of strncpy()")

unintentionally introduced a one byte out of bound read on strscpy()'s

source argument (which is kind of ironic knowing that strscpy() is meant

to be a more secure alternative :)).

Let's consider below buffers:

dest[len + 1]; /* will be NUL terminated */

src[len]; /* may not be NUL terminated */

When doing:

strncpy(dest, src, len);

dest[len] = '\0';

strncpy() will read up to len bytes from src.

On the other hand:

strscpy(dest, src, len + 1);

will read up to len + 1 bytes from src, that is to say, an out of bound

read of one byte will occur on src if it is not NUL terminated. Note

that the src[len] byte is never copied, but strscpy() still needs to

read it to check whether a truncation occurred or not.

This exact pattern happened in ucan.

The root cause is that the source is

/// 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