USB: misc: uss720: unregister parport on probe failure

uss720_probe() registers a parport before reading the 1284 register used
to detect unsupported Belkin F5U002 adapters. If get_1284_register()
fails, the error path drops the driver private data and the USB device
reference, but leaves the parport device registered.

Leaving the port registered is more than a private allocation leak:
parport_register_port() has already reserved a parport number and
registered the parport bus device, while pp->private_data still points at
the private data that the common error path is about to release.

Undo the pre-announce registration in the get_1284_register() failure
branch before jumping to the common private-data cleanup path. Clear
priv->pp first, matching the disconnect path and avoiding a stale pointer
in the private data.

This issue was identified during our ongoing static-analysis research while
reviewing kernel code.

Fixes: 3295f1b866bf ("usb: misc: uss720: check for incompatible versions of the Belkin F5U002")
Cc: stable <stable@kernel.org>
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Reviewed-by: Alex Henrie <alexhenrie24@gmail.com>
Link: https://patch.msgid.link/20260706151049.63470-1-mhun512@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c
index b7d3c44b970e95ec75799b8711ed937af404b4cf..1ce48f5832d719d37cd0f4795d58b2f55b9691b7 100644 (file)
--- a/drivers/usb/misc/uss720.c
+++ b/drivers/usb/misc/uss720.c
@@ -732,8 +732,11 @@ static int uss720_probe(struct usb_interface *intf,
         * here. */
        ret = get_1284_register(pp, 0, &reg, GFP_KERNEL);
        dev_dbg(&intf->dev, "reg: %7ph\n", priv->reg);
-       if (ret < 0)
+       if (ret < 0) {
+               priv->pp = NULL;
+               parport_del_port(pp);
                goto probe_abort;
+       }
 
        ret = usb_find_last_int_in_endpoint(interface, &epd);
        if (!ret) {