From: Lars-Peter Clausen <redacted>
Date: Fri, 6 May 2016 11:26:02 +0000 (+0200)
Subject: victor-dmm: Fix USB device list leak
X-Git-Tag: libsigrok-0.5.0~426
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=4af1f68f9a69daa22064c4b99831f6dee5c5fbb2;p=libsigrok.git

victor-dmm: Fix USB device list leak

The victor-dmm driver uses libusb_get_device_list() but neglects to call
the matching libusb_device_list_free() on the error path of libusb_open().
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/victor-dmm/api.c b/src/hardware/victor-dmm/api.c
index aefbe8b2..47854ee9 100644
--- a/src/hardware/victor-dmm/api.c
+++ b/src/hardware/victor-dmm/api.c
@@ -107,28 +107,13 @@ 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;
 
 	/* The device reports as HID class, so the kernel would have
 	 * claimed it. */