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 <[email protected]>
Reviewed-by: Benjamin Tissoires <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 5066df8..4d72c20 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -484,10 +484,16 @@
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;
}
