Realtek RTL2838UHIDIR, rev 2.00/1.00, addr 2

modena@makoto 17:13:04/140727(..)% sudo rtl_adsb
Found 1 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Tuner gain set to automatic.
Tuned to 1090000000 Hz.
Exact sample rate is: 2000000.052982 Hz
Sampling at 2000000 S/s.
Failed to submit transfer 0!
zsh: segmentation fault (core dumped)  sudo rtl_adsb

Then checked by gdb (You need to be root)

modena@makoto 17:13:55/140727(..)% \
sudo gdb /usr/pkg/bin/rtl_adsb rtl_adsb.core
GNU gdb (GDB) 7.3.1
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64--netbsd".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/pkg/bin/rtl_adsb...(no debugging symbols found)...done.
[New process 1]
[New process 2]
Core was generated by `rtl_adsb'.
Program terminated with signal 11, Segmentation fault.
#0  0x00007f7ff7404892 in libusb_cancel_transfer () from /usr/pkg/lib/libusb-1.0.so.0
(gdb) bt
#0  0x00007f7ff7404892 in libusb_cancel_transfer () from /usr/pkg/lib/libusb-1.0.so.0
#1  0x00007f7ff7805dbf in rtlsdr_read_async () from /usr/pkg/lib/librtlsdr.so.0
#2  0x00000000004027cf in main ()
(gdb) 

i386 does not have the same problem (NetBSD/i386 6.1.4)