I have exactly the same problem. Doing strace shows the following before "freesing":

futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
futex(0x818569c, FUTEX_WAKE, 1) = 0
ioctl(9, 0x4008642a, 0xbfa36418) = 0