HID: logitech-hidpp: check name retrieval return code

hidpp_devicenametype_get_device_name() may return a negative value on
protocol errors (for example, when the device is powered off).
Explicitly check this condition to avoid a long-running loop.

(0 cannot be returned as __name_length - index > 0, but check for it
anyway as it would otherwise result in an infinite loop.)

Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Peter Wu 2014-12-11 13:51:18 +01:00 committed by Jiri Kosina
parent 02cc097e62
commit 1430ee73b5
1 changed files with 8 additions and 2 deletions

View File

@ -484,10 +484,16 @@ static char *hidpp_get_device_name(struct hidpp_device *hidpp)
if (!name)
return NULL;
while (index < __name_length)
index += hidpp_devicenametype_get_device_name(hidpp,
while (index < __name_length) {
ret = hidpp_devicenametype_get_device_name(hidpp,
feature_index, index, name + index,
__name_length - index);
if (ret <= 0) {
kfree(name);
return NULL;
}
index += ret;
}
return name;
}