Am 25.05.2011 00:18 schrieb Greg KH:
> On Wed, May 25, 2011 at 12:02:48AM +0200, Carl-Daniel Hailfinger wrote:
>
>> I was playing with the "authorized" attribute of USB devices in
>> sysfs.
>> If at least one device has authorized=0,
>> "lsusb" will print nothing (not even the host controllers)
>>
> Well, if the device can't be accessed, as you disabled it through the
> authorised=0 setting, lsusb shouldn't really be able to do much with it.
>
Turns out there are two bugs:
libusb screws up walking the bus and claims there are -1 devices (error).
lsusb ignores that and tries to free a nonexisting object.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@xxxxxxx>
diff --git a/lsusb.c b/lsusb.c
index 6ba2288..edcc864 100644
--- a/lsusb.c
+++ b/lsusb.c
@@ -3861,6 +3861,8 @@ static int list_devices(libusb_context *ctx, int busnum, int devnum, int vendori
status = 1; /* 1 device not found, 0 device found */
num_devs = libusb_get_device_list(ctx, &list);
+ if (num_devs < 0)
+ goto error;
for (i = 0; i < num_devs; ++i) {
libusb_device *dev = list[i];
@@ -3890,6 +3892,7 @@ static int list_devices(libusb_context *ctx, int busnum, int devnum, int vendori
}
libusb_free_device_list(list, 0);
+error:
return status;
}
--
http://www.hailfinger.org/
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