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* usb_id segfaulting on 2.6.23
@ 2007-10-15 12:29 Daniel Drake
  2007-10-15 12:41 ` Kay Sievers
                   ` (15 more replies)
  0 siblings, 16 replies; 18+ messages in thread
From: Daniel Drake @ 2007-10-15 12:29 UTC (permalink / raw)
  To: linux-hotplug

Hi,

Since upgrading to 2.6.23, usb_id is segfaulting when dealing with my 
input devices. I'm using udev-116. I can get an instant segfault simply 
by replugging my keyboard.

I have dug around a bit. The segfault happens inside usb_id, see the 
"fallback" section.

It reaches here:
		dbg("No USB vendor information available\n");
		sprintf(vendor_str,"0000");

then a few lines later:

		set_str(vendor_str,usb_vendor, sizeof(vendor_str) - 1);

usb_vendor is NULL. set_str does various string manipulations with this 
NULL pointer which causes the segfault.

I suggest fixing this by replacing the sprintf line with:
	usb_vendor = "0000";

The same bug exists a few lines below with the USB model handling.


Now for what actually caused the change in behaviour: the devpath passed 
to usb_id has changed between 2.6.22 and 2.6.23.

In 2.6.22, it was /class/input/input4/event2 and I would get this output:

> # /lib/udev/usb_id /class/input/input4/event2
> Microsoft_Microsoft_Keyboard_with_Fingerprint_Reader_{3A1B506A-BB77-444C-851B-C424997B2763}
> ID_VENDOR=Microsoft
> ID_MODEL=Microsoft_Keyboard_with_Fingerprint_Reader
> ID_REVISION\x0100
> ID_SERIAL=Microsoft_Microsoft_Keyboard_with_Fingerprint_Reader_{3A1B506A-BB77-444C-851B-C424997B2763}
> ID_SERIAL_SHORT={3A1B506A-BB77-444C-851B-C424997B2763}
> ID_TYPE=hid
> ID_BUS=usb

In 2.6.23 the devpath now provided to usb_id is 
/devices/pci0000:00/0000:00:02.0/usb2/2-2/2-2:1.0/input/input13/event2

After applying my segfault fixes I get the following from usb_id:
> # /lib/udev/usb_id /devices/pci0000:00/0000:00:02.0/usb2/2-2/2-21.0/input/input13/event2
> 0000_0000

Why has the devpath changed? Is this a kernel bug for breaking userspace 
compat? Or should usb_id just be adapted to be able to handle both types 
of devpath?

Thanks!
Daniel


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^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2007-11-06 22:18 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-10-15 12:29 usb_id segfaulting on 2.6.23 Daniel Drake
2007-10-15 12:41 ` Kay Sievers
2007-10-15 12:58 ` Kay Sievers
2007-10-15 13:07 ` Daniel Drake
2007-10-15 21:19 ` Kay Sievers
2007-10-16 18:15 ` Kay Sievers
2007-11-06  0:42 ` Daniel Drake
2007-11-06  2:26 ` Kay Sievers
2007-11-06  7:42 ` Oliver Neukum
2007-11-06 11:47 ` Daniel Drake
2007-11-06 12:38 ` Oliver Neukum
2007-11-06 14:11 ` Oliver Neukum
2007-11-06 15:03 ` Daniel Drake
2007-11-06 16:11   ` Alan Stern
2007-11-06 16:05 ` Alan Stern
2007-11-06 17:51 ` Daniel Drake
2007-11-06 17:54 ` Daniel Drake
2007-11-06 22:18 ` Greg KH

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