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 9a984cdc84eb664e639fcad6842c2166a9f0e422..a6146e08d339603300ebaa027127cc696334d171 100644 (file)
--- 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) {