From: Lars-Peter Clausen <redacted>
Date: Fri, 6 May 2016 11:25:14 +0000 (+0200)
Subject: testo: Fix USB device list leak
X-Git-Tag: libsigrok-0.5.0~427
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=b75dc14a9410f57b3f7853854da013af86fb87c2;p=libsigrok.git

testo: Fix USB device list leak

The testo driver uses libusb_get_device_list() but neglects to call the
matching libusb_device_list_free() on the error path. This will leak the
memory allocated for the list as well as all the devices.

To address the issue use sr_usb_open() instead of open-coding its
functionality. sr_usb_open() correctly handles freeing the device list.

The issue was discovered using the following coccinelle semantic patch:
// <smpl>
@@
identifier devlist;
expression ctx, ret;
statement S;
@@
(
 libusb_get_device_list(ctx, &devlist);
|
 ret = libusb_get_device_list(ctx, &devlist);
 if (ret < 0) S
)
... when != libusb_free_device_list(devlist, ...)
*return ...;
// </smpl>

Signed-off-by: Lars-Peter Clausen <redacted>
---

diff --git a/src/hardware/testo/api.c b/src/hardware/testo/api.c
index 9a984cdc..a6146e08 100644
--- a/src/hardware/testo/api.c
+++ b/src/hardware/testo/api.c
@@ -150,27 +150,13 @@ static int dev_open(struct sr_dev_inst *sdi)
 	struct sr_dev_driver *di = sdi->driver;
 	struct drv_context *drvc = di->context;
 	struct sr_usb_dev_inst *usb;
-	libusb_device **devlist;
-	int ret, i;
-	char connection_id[64];
+	int ret;
 
 	usb = sdi->conn;
-	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
-	for (i = 0; devlist[i]; i++) {
-		usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
-		if (strcmp(sdi->connection_id, connection_id))
-			continue;
-		if ((ret = libusb_open(devlist[i], &usb->devhdl))) {
-			sr_err("Failed to open device: %s.", libusb_error_name(ret));
-			return SR_ERR;
-		}
-		break;
-	}
-	libusb_free_device_list(devlist, 1);
-	if (!devlist[i]) {
-		sr_err("Device not found.");
-		return SR_ERR;
-	}
+
+	ret = sr_usb_open(drvc->sr_ctx->libusb_ctx, usb);
+	if (ret != SR_OK)
+		return ret;
 
 	if (libusb_has_capability(LIBUSB_CAP_SUPPORTS_DETACH_KERNEL_DRIVER)) {
 		if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {