[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>

1 files changed, 57 insertions, 53 deletions

diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
index a384f80f595e..e9d017bea377 100644
--- 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;
 }
 
 /*