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

From: Alexey Khoroshilov
Date: Mon Oct 07 2013 - 17:06:40 EST


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@xxxxxxxxx>
---
drivers/media/usb/cx231xx/cx231xx-cards.c | 110 ++++++++++++++++--------------
1 file changed, 57 insertions(+), 53 deletions(-)

diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
index a384f80..e9d017b 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;
}

/*
--
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/