usb to parallel adapter causes segfault when adding printer

[Ole Streicher]

Binary package hint: cups

When I try to add a printer via usb-to-parallel, the printer is not recognized and the backend program will die with a segfault.

Dmesg reports:

[ 4875.810031] usb 3-1: new full speed USB device using ohci_hcd and address 5
[ 4876.033583] usb 3-1: configuration #1 chosen from 1 choice
[ 4876.107592] usblp0: USB Bidirectional printer dev 5 if 0 alt 0 proto 2 vid 0x1A86 pid 0x7584
[ 4876.107642] usbcore: registered new interface driver usblp
[ 4886.380286] usb 3-1: usbfs: interface 0 claimed by usblp while 'usb' sets config #1
[ 4886.416955] usb[8155]: segfault at 7fff03707000 ip 00007ff08cbc2b14 sp 00007fff03703248 error 4 in libc-2.10.1.so[7ff08cb40000+166000]

The last line can be reproduced by calling /usr/lib/cups/backend/usb by hand:

DEBUG: list_devices_libusb
DEBUG: usb_find_busses=4
DEBUG: usb_find_devices=6
Segmentation fault

The adapter is known to work under Ubuntu (worked at 9.04).
Affects kubuntu 9.10/amd64
cups version is 1.4.1-5ubuntu2.1

[Ole Streicher (olebole)]

I disabled the usblp kernel module.
When running /usr/lib/cups/backend/usb under strace, I get:

[...]
open("/dev/bus/usb/003/004", O_RDWR) = 3
ioctl(3, USBDEVFS_SETCONFIGURATION, 0x7fff4c1b19d4) = 0
ioctl(3, USBDEVFS_CLAIMINTERFACE, 0x7fff4c1b19cc) = 0
ioctl(3, USBDEVFS_SETINTERFACE, 0x7fff4c1b19c0) = 0
ioctl(3, USBDEVFS_CONTROL, 0x7fff4c1b1980) = 2
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++

/dev/bus/usb/003/004 is the device of the interface.

gdb says:
[...]
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7479b54 in ?? () from /lib/libc.so.6
(gdb) where
#0 0x00007ffff7479b54 in ?? () from /lib/libc.so.6
#1 0x00007ffff7477ede in memmove () from /lib/libc.so.6
#2 0x00007ffff7ff8d69 in ?? () from /usr/lib/cups/backend/usb
#3 0x00007ffff7ff9c33 in ?? () from /usr/lib/cups/backend/usb
#4 0x0d7800007ffff7ff in ?? ()
#5 0xab3500007ffff776 in ?? ()
#6 0xdd4000007ffff7ff in ?? ()
#7 0x000000007fffffff in ?? ()
#8 0x0000ffffffffb6a0 in ?? ()
#9 0x5e88ffffefbc86d6 in ?? ()
#10 0xf9d000007ffff73f in ?? ()
#11 0x2c5200007ffff7fc in ?? ()
#12 0x000100007ffff7de in ?? ()
#13 0xf4d000007fff0000 in ?? ()
#14 0x000100007ffff7fc in ?? ()
#15 0x0000000000000000 in ?? ()

[Aymeric Mansoux (aymeric)]

Same here on 9.10, I tried all kind of different things including pinning CUPS and related dependencies from lucid, it always lead to the same segmentation fault.

The only workaround that I found, to be able to use the printer again, was to blindly add a printer from the CUPS admin page and point it to "parallel:/dev/usb/lp0" (and then use the right PPD file, etc) as explained here: https://bugs.launchpad.net/ubuntu/+source/cups/+bug/436495