Fix: Potential buffer overflow errors

[af-a]

Description

We observed buffer overflow errors due to certain freesurfer commands that are executed in recon-surf (mri_label2vol and mris_anatomical_stats) when subject directory paths are too long.
This particulary occurs when a freesurfer version built for Ubuntu is run on a Centos machine, but may happen in other cases.

The following is an example of the error message (from recon-surf.log):

mri_label2vol --defects $SUBJECTS_DIR/$SUBJECT_ID/surf/lh.defect_labels \
    $SUBJECTS_DIR/$SUBJECT_ID/mri/orig.mgz 1000 0 \
    $SUBJECTS_DIR/$SUBJECT_ID/mri/lh.surface.defects.mgz
*** buffer overflow detected ***: terminated
Abort (core dumped)

This was the case when $SUBJECTS_DIR/$SUBJECT_ID was at least 192 characters long.

Solution

This PR adds a check in recon-surf.sh for the length of $SUBJECTS_DIR/$SUBJECT_ID, then raises an error and exits if it exceeds 185 characters.