USB: legousbtower: fix slab info leak at probe

BugLink: https://bugs.launchpad.net/bugs/1850541
commit 1d427be4a39defadda6dd8f4659bc17f7591740f upstream.

Make sure to check for short transfers when retrieving the version
information at probe to avoid leaking uninitialised slab data when
logging it.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190919083039.30898-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index c5be6e9e24a5583160055af5a9b851ae4c10b464..798008cfbbd6644994e68e1869be9c38f3e0bcb0 100644 (file)
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -890,8 +890,10 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
                                  get_version_reply,
                                  sizeof(*get_version_reply),
                                  1000);
-       if (result < 0) {
-               dev_err(idev, "LEGO USB Tower get version control request failed\n");
+       if (result < sizeof(*get_version_reply)) {
+               if (result >= 0)
+                       result = -EIO;
+               dev_err(idev, "get version request failed: %d\n", result);
                retval = result;
                goto error;
        }