Eric Allen has confirmed the signing on twitter.
Hardin is a 24-year old defensive back with great size (6-3, 217) and was a third round pick in the 2012 NFL draft. The Bears were taking a chance on Hardin, who missed the entire 2011 season with a shoulder injury, but his injury woes continued in the pros. In the 2012 preseason, Hardin suffered a scary neck injury that sidelined him for the season and this year he broke his scapula in preseason and was released with an injury settlement.
Hardin played at cornerback in 2010, but since being drafted by the Bears had been working as a free safety. He had 13 tackles and two passes defensed in six preseason games as a Bear.
He has good athleticism (4.43 forty time, 35.5 inch vertical and 124 inch broad jump at Oregon State's pro day) so could be a low-risk high-reward pickup if he can get healthy.