Slackware :: File Permission About Encrypted Swap

I use the follow command to create a encrypted swap:

Code:
bash# echo "cryptswap /dev/sda5 none swap" >> /etc/crypttab
and edit the 'fstab' file :

Code:
/dev/sda6 / ext4 defaults 1 1
/dev/mapper/cryptswap swap swap defaults 0 0

That's work fine, but I found the permission of '/dev/mapper/cryptswap' is like this:

Code:
hello@world:~$ ls -l /dev/mapper/cryptswap
brw-rw-r-- 1 root disk 253, 4 2010-05-28 12:55 /dev/mapper/cryptswap
Other users can read the file '/dev/mapper/cryptswap', does it harm the system's security ?