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

btrfs: add the missing error handling inside get_canonical_dev_path

Inside function get_canonical_dev_path(), we call d_path() to get the
final device path.

But d_path() can return error, and in that case the next strscpy() call
will trigger an invalid memory access.

Add back the missing error handling for d_path().

References

• https://nvd.nist.gov/vuln/detail/CVE-2025-21679
• https://git.kernel.org/stable/c/d0fb5741932b831eded49bfaaf33353e96200d6d
• https://git.kernel.org/stable/c/fe4de594f7a2e9bc49407de60fbd20809fad4192