usbip: tools: Fix read_usb_vudc_device() error path handling

This isn't really accurate right. fread() doesn't always
return 0 in error. It could return < number of elements
and set errno.

Signed-off-by: GwanYeong Kim <gy741.kim@gmail.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20191018032223.4644-1-gy741.kim@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/usb/usbip/libsrc/usbip_device_driver.c b/tools/usb/usbip/libsrc/usbip_device_driver.c
index 051d7d3f443b4f6663d38b5c190f9293ac51f359..927a151fa9aa9e52c5c721f20c34d1682575b17f 100644 (file)
--- a/tools/usb/usbip/libsrc/usbip_device_driver.c
+++ b/tools/usb/usbip/libsrc/usbip_device_driver.c
@@ -69,7 +69,7 @@ int read_usb_vudc_device(struct udev_device *sdev, struct usbip_usb_device *dev)
        FILE *fd = NULL;
        struct udev_device *plat;
        const char *speed;
-       int ret = 0;
+       size_t ret;
 
        plat = udev_device_get_parent(sdev);
        path = udev_device_get_syspath(plat);
@@ -79,8 +79,10 @@ int read_usb_vudc_device(struct udev_device *sdev, struct usbip_usb_device *dev)
        if (!fd)
                return -1;
        ret = fread((char *) &descr, sizeof(descr), 1, fd);
-       if (ret < 0)
+       if (ret != 1) {
+               err("Cannot read vudc device descr file: %s", strerror(errno));
                goto err;
+       }
        fclose(fd);
 
        copy_descr_attr(dev, &descr, bDeviceClass);