[media] cx231xx: fix double free and leaks on failure path in cx231xx_usb_probe()

There are numerous issues in error handling code of cx231xx initialization.
Double free (when cx231xx_init_dev() calls kfree(dev) via cx231xx_release_resources()
and then cx231xx_usb_probe() does the same) and memory leaks
(e.g. usb_get_dev() before (ifnum != 1) check in cx231xx_usb_probe())
are just a few of them.
The patch fixes the issues in cx231xx_usb_probe() and cx231xx_init_dev()
by moving usb_get_dev(interface_to_usbdev(interface)) below in code and
implementing proper error handling.
Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
index a384f80..e9d017b 100644 (file)
--- a/drivers/media/usb/cx231xx/cx231xx-cards.c
+++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
@@ -978,7 +978,6 @@ static int cx231xx_init_dev(struct cx231xx *dev, struct usb_device *udev,
                            int minor)
 {
        int retval = -ENOMEM;
-       int errCode;
        unsigned int maxh, maxw;
 
        dev->udev = udev;
@@ -1014,8 +1013,8 @@ static int cx231xx_init_dev(struct cx231xx *dev, struct usb_device *udev,
        /* Cx231xx pre card setup */
        cx231xx_pre_card_setup(dev);
 
-       errCode = cx231xx_config(dev);
-       if (errCode) {
+       retval = cx231xx_config(dev);
+       if (retval) {
                cx231xx_errdev("error configuring device\n");
                return -ENOMEM;
        }
@@ -1024,12 +1023,11 @@ static int cx231xx_init_dev(struct cx231xx *dev, struct usb_device *udev,
        dev->norm = dev->board.norm;
 
        /* register i2c bus */
-       errCode = cx231xx_dev_init(dev);
-       if (errCode < 0) {
-               cx231xx_dev_uninit(dev);
+       retval = cx231xx_dev_init(dev);
+       if (retval) {
                cx231xx_errdev("%s: cx231xx_i2c_register - errCode [%d]!\n",
-                              __func__, errCode);
-               return errCode;
+                              __func__, retval);
+               goto err_dev_init;
        }
 
        /* Do board specific init */
@@ -1047,11 +1045,11 @@ static int cx231xx_init_dev(struct cx231xx *dev, struct usb_device *udev,
        dev->interlaced = 0;
        dev->video_input = 0;
 
-       errCode = cx231xx_config(dev);
-       if (errCode < 0) {
+       retval = cx231xx_config(dev);
+       if (retval) {
                cx231xx_errdev("%s: cx231xx_config - errCode [%d]!\n",
-                              __func__, errCode);
-               return errCode;
+                              __func__, retval);
+               goto err_dev_init;
        }
 
        /* init video dma queues */
@@ -1075,9 +1073,9 @@ static int cx231xx_init_dev(struct cx231xx *dev, struct usb_device *udev,
        }
 
        retval = cx231xx_register_analog_devices(dev);
-       if (retval < 0) {
-               cx231xx_release_resources(dev);
-               return retval;
+       if (retval) {
+               cx231xx_release_analog_resources(dev);
+               goto err_analog;
        }
 
        cx231xx_ir_init(dev);
@@ -1085,6 +1083,11 @@ static int cx231xx_init_dev(struct cx231xx *dev, struct usb_device *udev,
        cx231xx_init_extension(dev);
 
        return 0;
+err_analog:
+       cx231xx_remove_from_devlist(dev);
+err_dev_init:
+       cx231xx_dev_uninit(dev);
+       return retval;
 }
 
 #if defined(CONFIG_MODULES) && defined(MODULE)
@@ -1132,7 +1135,6 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
        char *speed;
        struct usb_interface_assoc_descriptor *assoc_desc;
 
-       udev = usb_get_dev(interface_to_usbdev(interface));
        ifnum = interface->altsetting[0].desc.bInterfaceNumber;
 
        /*
@@ -1161,6 +1163,8 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
                return -ENOMEM;
        }
 
+       udev = usb_get_dev(interface_to_usbdev(interface));
+
        snprintf(dev->name, 29, "cx231xx #%d", nr);
        dev->devno = nr;
        dev->model = id->driver_info;
@@ -1223,10 +1227,8 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
        if (assoc_desc->bFirstInterface != ifnum) {
                cx231xx_err(DRIVER_NAME ": Not found "
                            "matching IAD interface\n");
-               clear_bit(dev->devno, &cx231xx_devused);
-               kfree(dev);
-               dev = NULL;
-               return -ENODEV;
+               retval = -ENODEV;
+               goto err_if;
        }
 
        cx231xx_info("registering interface %d\n", ifnum);
@@ -1242,22 +1244,13 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
        retval = v4l2_device_register(&interface->dev, &dev->v4l2_dev);
        if (retval) {
                cx231xx_errdev("v4l2_device_register failed\n");
-               clear_bit(dev->devno, &cx231xx_devused);
-               kfree(dev);
-               dev = NULL;
-               return -EIO;
+               retval = -EIO;
+               goto err_v4l2;
        }
        /* allocate device struct */
        retval = cx231xx_init_dev(dev, udev, nr);
-       if (retval) {
-               clear_bit(dev->devno, &cx231xx_devused);
-               v4l2_device_unregister(&dev->v4l2_dev);
-               kfree(dev);
-               dev = NULL;
-               usb_set_intfdata(interface, NULL);
-
-               return retval;
-       }
+       if (retval)
+               goto err_init;
 
        /* compute alternate max packet sizes for video */
        uif = udev->actconfig->interface[dev->current_pcb_config.
@@ -1275,11 +1268,8 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
 
        if (dev->video_mode.alt_max_pkt_size == NULL) {
                cx231xx_errdev("out of memory!\n");
-               clear_bit(dev->devno, &cx231xx_devused);
-               v4l2_device_unregister(&dev->v4l2_dev);
-               kfree(dev);
-               dev = NULL;
-               return -ENOMEM;
+               retval = -ENOMEM;
+               goto err_video_alt;
        }
 
        for (i = 0; i < dev->video_mode.num_alt; i++) {
@@ -1309,11 +1299,8 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
 
        if (dev->vbi_mode.alt_max_pkt_size == NULL) {
                cx231xx_errdev("out of memory!\n");
-               clear_bit(dev->devno, &cx231xx_devused);
-               v4l2_device_unregister(&dev->v4l2_dev);
-               kfree(dev);
-               dev = NULL;
-               return -ENOMEM;
+               retval = -ENOMEM;
+               goto err_vbi_alt;
        }
 
        for (i = 0; i < dev->vbi_mode.num_alt; i++) {
@@ -1344,11 +1331,8 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
 
        if (dev->sliced_cc_mode.alt_max_pkt_size == NULL) {
                cx231xx_errdev("out of memory!\n");
-               clear_bit(dev->devno, &cx231xx_devused);
-               v4l2_device_unregister(&dev->v4l2_dev);
-               kfree(dev);
-               dev = NULL;
-               return -ENOMEM;
+               retval = -ENOMEM;
+               goto err_sliced_cc_alt;
        }
 
        for (i = 0; i < dev->sliced_cc_mode.num_alt; i++) {
@@ -1380,11 +1364,8 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
 
                if (dev->ts1_mode.alt_max_pkt_size == NULL) {
                        cx231xx_errdev("out of memory!\n");
-                       clear_bit(dev->devno, &cx231xx_devused);
-                       v4l2_device_unregister(&dev->v4l2_dev);
-                       kfree(dev);
-                       dev = NULL;
-                       return -ENOMEM;
+                       retval = -ENOMEM;
+                       goto err_ts1_alt;
                }
 
                for (i = 0; i < dev->ts1_mode.num_alt; i++) {
@@ -1411,6 +1392,29 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
        request_modules(dev);
 
        return 0;
+err_ts1_alt:
+       kfree(dev->sliced_cc_mode.alt_max_pkt_size);
+err_sliced_cc_alt:
+       kfree(dev->vbi_mode.alt_max_pkt_size);
+err_vbi_alt:
+       kfree(dev->video_mode.alt_max_pkt_size);
+err_video_alt:
+       /* cx231xx_uninit_dev: */
+       cx231xx_close_extension(dev);
+       cx231xx_ir_exit(dev);
+       cx231xx_release_analog_resources(dev);
+       cx231xx_417_unregister(dev);
+       cx231xx_remove_from_devlist(dev);
+       cx231xx_dev_uninit(dev);
+err_init:
+       v4l2_device_unregister(&dev->v4l2_dev);
+err_v4l2:
+       usb_set_intfdata(interface, NULL);
+err_if:
+       usb_put_dev(udev);
+       kfree(dev);
+       clear_bit(dev->devno, &cx231xx_devused);
+       return retval;
 }
 
 /*