Linux – Change permissions for mounted veracrypt drive in linux

When mounting, use -o uid=youruid. Then, all files on that cifs share will be owned by you so that you can edit/remove them.
E.g.:

mount -o uid=1000 //nas/share /SharedMountPoint

You can find your numeric uid in /etc/passwd

grep `whoami` /etc/passwd | cut -d : -f 3

or:

id -u `whoami`

CentOS enables SELinux by default, which adds additional security restrictions on the system. Default policy mostly covers the typical/default configurations for confined software. When access is denied, usually a log entry is generated in audit logs in /var/log/audit/audit.log.

With a removable media you should consider mounting the device with SELinux context option. This way you avoid modifying your system's SELinux policy and the need for filesystem relabeling on the removable device. You can use samba_share_t if you only intend to make the mount point to be used with samba. If you use/label user_home_t type, the files will be treated as if they were in user home directory.

mount -t ext4 /dev/sdb /mnt/ELEMENTERY-1TB \
      -o context="system_u:object_r:samba_share_t:s0"

Or in /etc/fstab

UUID=<...> /mnt/ELEMENTERY-1TB/ ext4 defaults,errors=remount-ro,context="system_u:object_r:samba_share_t:s0" 0 1

If you still have issues with SELinux, you can use audit2why to find out why access was denied, and possibly if a SELinux boolean exists to allow access. In case you need to alter SELinux policy, you can use audit2allow to generate a policy module to allow access.

There are also two booleans samba_export_all_ro and samba_export_all_rw when enabled allow samba to access (and share) any files. In this case this allows samba significantly more access than required and therefore should not be used in this situation as mount options can be configured easily.