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Subject[RFT] [media] siano: FIX use-after-free in worker_thread
Date
If CONFIG_MEDIA_CONTROLLER_DVB is enable, We are not releasing
media device and memory on any failure or disconnect a device.

Adding structure media_device 'mdev' as part of 'smsusb_device_t'
structure to make proper handle for media device.
Now releasing a media device and memory on failure. It's allocate
first in siano_media_device_register() and it should be freed last
in smsusb_disconnect().

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
---
This bug report by Andrey Konovalov "usb/media/smsusb: use-after-free in
worker_thread".

drivers/media/usb/siano/smsusb.c | 45 ++++++++++++++++++++++++----------------
1 file changed, 27 insertions(+), 18 deletions(-)

diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c
index 8c1f926..66936b3 100644
--- a/drivers/media/usb/siano/smsusb.c
+++ b/drivers/media/usb/siano/smsusb.c
@@ -69,6 +69,9 @@ struct smsusb_device_t {
unsigned char in_ep;
unsigned char out_ep;
enum smsusb_state state;
+#ifdef CONFIG_MEDIA_CONTROLLER_DVB
+ struct media_device *mdev;
+#endif
};

static int smsusb_submit_urb(struct smsusb_device_t *dev,
@@ -359,6 +362,13 @@ static void smsusb_term_device(struct usb_interface *intf)
if (dev->coredev)
smscore_unregister_device(dev->coredev);

+#ifdef CONFIG_MEDIA_CONTROLLER_DVB
+ if (dev->mdev) {
+ media_device_unregister(dev->mdev);
+ media_device_cleanup(dev->mdev);
+ kfree(dev->mdev);
+ }
+#endif
pr_debug("device 0x%p destroyed\n", dev);
kfree(dev);
}
@@ -370,27 +380,28 @@ static void *siano_media_device_register(struct smsusb_device_t *dev,
int board_id)
{
#ifdef CONFIG_MEDIA_CONTROLLER_DVB
- struct media_device *mdev;
struct usb_device *udev = dev->udev;
struct sms_board *board = sms_get_board(board_id);
int ret;

- mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
- if (!mdev)
+ dev->mdev = kzalloc(sizeof(*dev->mdev), GFP_KERNEL);
+ if (!dev->mdev)
return NULL;

- media_device_usb_init(mdev, udev, board->name);

- ret = media_device_register(mdev);
+ media_device_usb_init(dev->mdev, udev, board->name);
+
+ ret = media_device_register(dev->mdev);
if (ret) {
- media_device_cleanup(mdev);
- kfree(mdev);
+ media_device_cleanup(dev->mdev);
+ kfree(dev->mdev);
+ dev->mdev = NULL;
return NULL;
}

pr_info("media controller created\n");

- return mdev;
+ return dev->mdev;
#else
return NULL;
#endif
@@ -458,12 +469,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id)
rc = smscore_register_device(&params, &dev->coredev, mdev);
if (rc < 0) {
pr_err("smscore_register_device(...) failed, rc %d\n", rc);
- smsusb_term_device(intf);
-#ifdef CONFIG_MEDIA_CONTROLLER_DVB
- media_device_unregister(mdev);
-#endif
- kfree(mdev);
- return rc;
+ goto err_smsusb_init;
}

smscore_set_board_id(dev->coredev, board_id);
@@ -480,8 +486,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id)
rc = smsusb_start_streaming(dev);
if (rc < 0) {
pr_err("smsusb_start_streaming(...) failed\n");
- smsusb_term_device(intf);
- return rc;
+ goto err_smsusb_init;
}

dev->state = SMSUSB_ACTIVE;
@@ -489,13 +494,17 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id)
rc = smscore_start_device(dev->coredev);
if (rc < 0) {
pr_err("smscore_start_device(...) failed\n");
- smsusb_term_device(intf);
- return rc;
+ goto err_smsusb_init;
}

pr_debug("device 0x%p created\n", dev);

return rc;
+
+err_smsusb_init:
+ smsusb_term_device(intf);
+
+ return rc;
}

static int smsusb_probe(struct usb_interface *intf,
--
1.9.1
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