Created attachment 322251 [details]
Patch to apply to hotplug_libusb.c

Description of problem:
I am writing an ifd driver for an USB smartcard reader.

It seems that this reader doesn't have an USB "serial number" property defined.

When detecting the reader, PCSC-lite adds random garbage to the reader name, and there is some memory corruption which
prevent the normal function of the PCSC stack.
(PCSC-lite is compiled with ADD_SERIAL_NUMBER)

I traced this problem back to the file hotplug_libusb.c and provide a simple fix to this problem.

With this patch, the problem is gone, the driver does function normally and there is no garbage neither in the logs
or in the reader name.

Version-Release number of selected component (if applicable):
pcsc-lite-1.4.4-3.fc9.i386

How reproducible:
Not easy : you have to use PCSC-lite with an USB Smartcard reader which DOES NOT have an USB Serial Number defined.
The reader is an Infinity USB Unlimited ( http://www.infinityusb.com/default.asp?show=productsdetail&ProductID=11 ), here is the "lsusb -v" output :
====================
Bus 005 Device 047: ID 104f:0004  
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x104f 
  idProduct          0x0004 
  bcdDevice            1.00
  iManufacturer           1 WB Electronics
  iProduct                2 Infinity USB Unlimited
  iSerial                 3 
  bNumConfigurations      1
...
====================

To reproduce, you also have to have a driver for this reader, and since I haven't released one yet, it's not that easy.

Steps to Reproduce:
1. Plug the reader in
2. look at the log
  
Actual results:
(Random garbage appended to the reader name)
Nov  2 21:28:49 xps pcscd: readerfactory.c:1113:RFInitializeReader() Attempting startup of IUSB (#010¢#004¸#030¢#004¸ß<97>þ#002#010¢#004¸#010¢#004¸$<9c>O) 00 00 using /usr/lib/pcsc/drivers/ifd-iuu.bundle/Contents/Linux/libiuu.so.1.0.0

Expected results:
(No serial number)
Nov  2 21:28:49 xps pcscd: readerfactory.c:1113:RFInitializeReader() Attempting startup of IUSB 00 00 using /usr/lib/pcsc/drivers/ifd-iuu.bundle/Contents/Linux/libiuu.so.1.0.0

Additional info:
* In the patch, I completely suppress the serial number output if there is an error retrieving the serial number property (len <= 0 denotes an error or an empty string)
* I've sent the patch upstream to PCSC developpers, so may be it'll be fixed in the current sources one day.