From: Vincent Palatin <redacted>
Date: Mon, 10 Nov 2014 16:17:07 +0000 (-0800)
Subject: usb_get_port_path(): fix libusb error checking
X-Git-Tag: libsigrok-0.4.0~716
X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=commitdiff_plain;h=2f004b4bc15c891b474adcba59a2224f009828af

usb_get_port_path(): fix libusb error checking

When libusb cannot access a device, libusb_get_port_numbers() will return
an error. Check the return code rather than doing invalid pointer
operations (out-of-bound read).

Avoid segfaults at sigrok-cli startup on my setup where some USB devices are
not accessible and also make Valgrind happier.

Signed-off-by: Vincent Palatin <redacted>
---

diff --git a/src/usb.c b/src/usb.c
index ec502c97..8bdb8d60 100644
--- a/src/usb.c
+++ b/src/usb.c
@@ -278,6 +278,9 @@ SR_PRIV int usb_get_port_path(libusb_device *dev, char *path, int path_len)
 
 	n = libusb_get_port_numbers(dev, port_numbers, sizeof(port_numbers));
 
+	if (n < 1)
+		return SR_ERR;
+
 	len = snprintf(path, path_len, "usb/%d-%d",
 	               libusb_get_bus_number(dev), port_numbers[0]);