media: dvb-usb: Fix memory leak at error in dvb_usb_device_init()

dvb_usb_device_init() allocates a dvb_usb_device object, but it
doesn't release the object by itself even at errors.  The object is
released in the callee side (dvb_usb_init()) in some error cases via
dvb_usb_exit() call, but it also missed the object free in other error
paths.  And, the caller (it's only dvb_usb_device_init()) doesn't seem
caring the resource management as well, hence those memories are
leaked.

This patch assures releasing the memory at the error path in
dvb_usb_device_init().  Now dvb_usb_init() frees the resources it
allocated but leaves the passed dvb_usb_device object intact.  In
turn, the dvb_usb_device object is released in dvb_usb_device_init()
instead.
We could use dvb_usb_exit() function for releasing everything in the
callee (as it was used for some error cases in the original code), but
releasing the passed object in the callee is non-intuitive and
error-prone.  So I took this approach (which is more standard in Linus
kernel code) although it ended with a bit more open codes.

Along with the change, the patch makes sure that USB intfdata is reset
and don't return the bogus pointer to the caller of
dvb_usb_device_init() at the error path, too.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
index c1a7634e27b434a08b77c8bed552aa9d5e8e6d35..c78158d12540dfe9ba77b1353db61e886bebceb0 100644 (file)
--- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
@@ -158,22 +158,20 @@ static int dvb_usb_init(struct dvb_usb_device *d, short *adapter_nums)
 
                if (d->props.priv_init != NULL) {
                        ret = d->props.priv_init(d);
-                       if (ret != 0) {
-                               kfree(d->priv);
-                               d->priv = NULL;
-                               return ret;
-                       }
+                       if (ret != 0)
+                               goto err_priv_init;
                }
        }
 
        /* check the capabilities and set appropriate variables */
        dvb_usb_device_power_ctrl(d, 1);
 
-       if ((ret = dvb_usb_i2c_init(d)) ||
-               (ret = dvb_usb_adapter_init(d, adapter_nums))) {
-               dvb_usb_exit(d);
-               return ret;
-       }
+       ret = dvb_usb_i2c_init(d);
+       if (ret)
+               goto err_i2c_init;
+       ret = dvb_usb_adapter_init(d, adapter_nums);
+       if (ret)
+               goto err_adapter_init;
 
        if ((ret = dvb_usb_remote_init(d)))
                err("could not initialize remote control.");
@@ -181,6 +179,17 @@ static int dvb_usb_init(struct dvb_usb_device *d, short *adapter_nums)
        dvb_usb_device_power_ctrl(d, 0);
 
        return 0;
+
+err_adapter_init:
+       dvb_usb_adapter_exit(d);
+err_i2c_init:
+       dvb_usb_i2c_exit(d);
+       if (d->priv && d->props.priv_destroy)
+               d->props.priv_destroy(d);
+err_priv_init:
+       kfree(d->priv);
+       d->priv = NULL;
+       return ret;
 }
 
 /* determine the name and the state of the just found USB device */
@@ -281,15 +290,21 @@ int dvb_usb_device_init(struct usb_interface *intf,
 
        usb_set_intfdata(intf, d);
 
-       if (du != NULL)
+       ret = dvb_usb_init(d, adapter_nums);
+       if (ret) {
+               info("%s error while loading driver (%d)", desc->name, ret);
+               goto error;
+       }
+
+       if (du)
                *du = d;
 
-       ret = dvb_usb_init(d, adapter_nums);
+       info("%s successfully initialized and connected.", desc->name);
+       return 0;
 
-       if (ret == 0)
-               info("%s successfully initialized and connected.", desc->name);
-       else
-               info("%s error while loading driver (%d)", desc->name, ret);
+ error:
+       usb_set_intfdata(intf, NULL);
+       kfree(d);
        return ret;
 }
 EXPORT_SYMBOL(dvb_usb_device_init);