Description of problem: Newer versions of HPLIP (1.7.4a onwards) need to be able to write to usbfs_t. 2.x.x does this as cupsd_t (straight from the CUPS backend), while 1.x.x does it from hpiod which is hplip_t.
Created attachment 158222 [details] hplip-usbfs.patch
Fixed in selinux-policy-2.6.4-24
Fix confirmed. Thanks.
Closing as fixes are in the current release