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* [Linux-kernel-mentees] [PATCH v3] Media: Radio: Change devm_k*alloc to k*alloc
@ 2019-06-18  5:42 ` Luke Nowakowski-Krijger
  0 siblings, 0 replies; 4+ messages in thread
From: lnowakow @ 2019-06-18  5:42 UTC (permalink / raw)


Change devm_k*alloc to k*alloc to manually allocate memory. Memory is freed in v4l2.release callback which now calls raremono_device_release to free up the appropriate memory, just like in radio-shark driver. 

This patch aims to fix the use-after-free read described in
https://syzkaller.appspot.com/bug?extid=a4387f5b6b799f6becbf

Signed-off-by: Luke Nowakowski-Krijger <lnowakow at eng.ucsd.edu>
---
diff --git a/drivers/media/radio/radio-raremono.c b/drivers/media/radio/radio-raremono.c
index 5e782b3c2fa9..b467ad7fdd21 100644
--- a/drivers/media/radio/radio-raremono.c
+++ b/drivers/media/radio/radio-raremono.c
@@ -271,6 +271,15 @@ static int vidioc_g_frequency(struct file *file, void *priv,
        return 0;
 }
 
+static void raremono_device_release(struct v4l2_device *v4l2_dev)
+{
+       struct raremono_device *radio = to_raremono_dev(v4l2_dev);
+       
+       kfree(radio->buffer);
+       kfree(radio);
+}
+
+
 /* File system interface */
 static const struct v4l2_file_operations usb_raremono_fops = {
        .owner          = THIS_MODULE,
@@ -295,12 +304,15 @@ static int usb_raremono_probe(struct usb_interface *intf,
        struct raremono_device *radio;
        int retval = 0;
 
-       radio = devm_kzalloc(&intf->dev, sizeof(struct raremono_device), GFP_KERNEL);
-       if (radio)
-               radio->buffer = devm_kmalloc(&intf->dev, BUFFER_LENGTH, GFP_KERNEL);
-
-       if (!radio || !radio->buffer)
+       radio = kzalloc(sizeof(struct raremono_device), GFP_KERNEL);
+       if (!radio)
                return -ENOMEM;
+       
+       radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
+       if (!radio->buffer) {
+               kfree(radio);
+               return -ENOMEM;
+       }
 
        radio->usbdev = interface_to_usbdev(intf);
        radio->intf = intf;
@@ -324,7 +336,9 @@ static int usb_raremono_probe(struct usb_interface *intf,
        if (retval != 3 ||
            (get_unaligned_be16(&radio->buffer[1]) & 0xfff) == 0x0242) {
                dev_info(&intf->dev, "this is not Thanko's Raremono.\n");
-               return -ENODEV;
+               
+               retval = -ENODEV;
+               goto free_mem;
        }
 
        dev_info(&intf->dev, "Thanko's Raremono connected: (%04X:%04X)\n",
@@ -333,7 +347,7 @@ static int usb_raremono_probe(struct usb_interface *intf,
       retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
        if (retval < 0) {
                dev_err(&intf->dev, "couldn't register v4l2_device\n");
-               return retval;
+               goto free_mem;
        }
 
        mutex_init(&radio->lock);
@@ -345,6 +359,8 @@ static int usb_raremono_probe(struct usb_interface *intf,
        radio->vdev.ioctl_ops = &usb_raremono_ioctl_ops;
        radio->vdev.lock = &radio->lock;
        radio->vdev.release = video_device_release_empty;
+       
+       radio->v4l2_dev.release = raremono_device_release;
 
        usb_set_intfdata(intf, &radio->v4l2_dev);
 
@@ -353,13 +369,20 @@ static int usb_raremono_probe(struct usb_interface *intf,
        raremono_cmd_main(radio, BAND_FM, 95160);
 
        retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
+       
        if (retval == 0) {
                dev_info(&intf->dev, "V4L2 device registered as %s\n",
                                video_device_node_name(&radio->vdev));
                return 0;
        }
+       
        dev_err(&intf->dev, "could not register video device\n");
        v4l2_device_unregister(&radio->v4l2_dev);
+
+free_mem:
+       kfree(radio->buffer);
+       kfree(radio);
+
        return retval;
 }

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [Linux-kernel-mentees] [PATCH v3] Media: Radio: Change devm_k*alloc to k*alloc
@ 2019-06-18  5:42 ` Luke Nowakowski-Krijger
  0 siblings, 0 replies; 4+ messages in thread
From: Luke Nowakowski-Krijger @ 2019-06-18  5:42 UTC (permalink / raw)


Change devm_k*alloc to k*alloc to manually allocate memory. Memory is freed in v4l2.release callback which now calls raremono_device_release to free up the appropriate memory, just like in radio-shark driver. 

This patch aims to fix the use-after-free read described in
https://syzkaller.appspot.com/bug?extid=a4387f5b6b799f6becbf

Signed-off-by: Luke Nowakowski-Krijger <lnowakow at eng.ucsd.edu>
---
diff --git a/drivers/media/radio/radio-raremono.c b/drivers/media/radio/radio-raremono.c
index 5e782b3c2fa9..b467ad7fdd21 100644
--- a/drivers/media/radio/radio-raremono.c
+++ b/drivers/media/radio/radio-raremono.c
@@ -271,6 +271,15 @@ static int vidioc_g_frequency(struct file *file, void *priv,
        return 0;
 }
 
+static void raremono_device_release(struct v4l2_device *v4l2_dev)
+{
+       struct raremono_device *radio = to_raremono_dev(v4l2_dev);
+       
+       kfree(radio->buffer);
+       kfree(radio);
+}
+
+
 /* File system interface */
 static const struct v4l2_file_operations usb_raremono_fops = {
        .owner          = THIS_MODULE,
@@ -295,12 +304,15 @@ static int usb_raremono_probe(struct usb_interface *intf,
        struct raremono_device *radio;
        int retval = 0;
 
-       radio = devm_kzalloc(&intf->dev, sizeof(struct raremono_device), GFP_KERNEL);
-       if (radio)
-               radio->buffer = devm_kmalloc(&intf->dev, BUFFER_LENGTH, GFP_KERNEL);
-
-       if (!radio || !radio->buffer)
+       radio = kzalloc(sizeof(struct raremono_device), GFP_KERNEL);
+       if (!radio)
                return -ENOMEM;
+       
+       radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
+       if (!radio->buffer) {
+               kfree(radio);
+               return -ENOMEM;
+       }
 
        radio->usbdev = interface_to_usbdev(intf);
        radio->intf = intf;
@@ -324,7 +336,9 @@ static int usb_raremono_probe(struct usb_interface *intf,
        if (retval != 3 ||
            (get_unaligned_be16(&radio->buffer[1]) & 0xfff) == 0x0242) {
                dev_info(&intf->dev, "this is not Thanko's Raremono.\n");
-               return -ENODEV;
+               
+               retval = -ENODEV;
+               goto free_mem;
        }
 
        dev_info(&intf->dev, "Thanko's Raremono connected: (%04X:%04X)\n",
@@ -333,7 +347,7 @@ static int usb_raremono_probe(struct usb_interface *intf,
       retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
        if (retval < 0) {
                dev_err(&intf->dev, "couldn't register v4l2_device\n");
-               return retval;
+               goto free_mem;
        }
 
        mutex_init(&radio->lock);
@@ -345,6 +359,8 @@ static int usb_raremono_probe(struct usb_interface *intf,
        radio->vdev.ioctl_ops = &usb_raremono_ioctl_ops;
        radio->vdev.lock = &radio->lock;
        radio->vdev.release = video_device_release_empty;
+       
+       radio->v4l2_dev.release = raremono_device_release;
 
        usb_set_intfdata(intf, &radio->v4l2_dev);
 
@@ -353,13 +369,20 @@ static int usb_raremono_probe(struct usb_interface *intf,
        raremono_cmd_main(radio, BAND_FM, 95160);
 
        retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
+       
        if (retval == 0) {
                dev_info(&intf->dev, "V4L2 device registered as %s\n",
                                video_device_node_name(&radio->vdev));
                return 0;
        }
+       
        dev_err(&intf->dev, "could not register video device\n");
        v4l2_device_unregister(&radio->v4l2_dev);
+
+free_mem:
+       kfree(radio->buffer);
+       kfree(radio);
+
        return retval;
 }

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [Linux-kernel-mentees] [PATCH v3] Media: Radio: Change devm_k*alloc to k*alloc
@ 2019-06-18  6:10   ` Greg KH
  0 siblings, 0 replies; 4+ messages in thread
From: gregkh @ 2019-06-18  6:10 UTC (permalink / raw)


On Mon, Jun 17, 2019 at 10:42:49PM -0700, Luke Nowakowski-Krijger wrote:
> Change devm_k*alloc to k*alloc to manually allocate memory. Memory is freed in v4l2.release callback which now calls raremono_device_release to free up the appropriate memory, just like in radio-shark driver. 

Please properly wrap your changelog text at 72 columns and do not add
trailing whitespace.

> 
> This patch aims to fix the use-after-free read described in
> https://syzkaller.appspot.com/bug?extid=a4387f5b6b799f6becbf

Does it?  Did you submit it to syzkaller and get any results?

There is a proper way to credit the tool as well, please do that.

> 
> Signed-off-by: Luke Nowakowski-Krijger <lnowakow at eng.ucsd.edu>
> ---
> diff --git a/drivers/media/radio/radio-raremono.c b/drivers/media/radio/radio-raremono.c
> index 5e782b3c2fa9..b467ad7fdd21 100644
> --- a/drivers/media/radio/radio-raremono.c
> +++ b/drivers/media/radio/radio-raremono.c
> @@ -271,6 +271,15 @@ static int vidioc_g_frequency(struct file *file, void *priv,
>         return 0;
>  }
>  
> +static void raremono_device_release(struct v4l2_device *v4l2_dev)
> +{
> +       struct raremono_device *radio = to_raremono_dev(v4l2_dev);
> +       

Trailing whitespace :(

Did you run your patch through checkpatch?

> +       kfree(radio->buffer);
> +       kfree(radio);
> +}
> +
> +
>  /* File system interface */
>  static const struct v4l2_file_operations usb_raremono_fops = {
>         .owner          = THIS_MODULE,
> @@ -295,12 +304,15 @@ static int usb_raremono_probe(struct usb_interface *intf,
>         struct raremono_device *radio;
>         int retval = 0;
>  
> -       radio = devm_kzalloc(&intf->dev, sizeof(struct raremono_device), GFP_KERNEL);
> -       if (radio)
> -               radio->buffer = devm_kmalloc(&intf->dev, BUFFER_LENGTH, GFP_KERNEL);
> -
> -       if (!radio || !radio->buffer)
> +       radio = kzalloc(sizeof(struct raremono_device), GFP_KERNEL);
> +       if (!radio)
>                 return -ENOMEM;
> +       

Trailing whitespace :(

> +       radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
> +       if (!radio->buffer) {
> +               kfree(radio);
> +               return -ENOMEM;
> +       }
>  
>         radio->usbdev = interface_to_usbdev(intf);
>         radio->intf = intf;
> @@ -324,7 +336,9 @@ static int usb_raremono_probe(struct usb_interface *intf,
>         if (retval != 3 ||
>             (get_unaligned_be16(&radio->buffer[1]) & 0xfff) == 0x0242) {
>                 dev_info(&intf->dev, "this is not Thanko's Raremono.\n");
> -               return -ENODEV;
> +               

More trailing whitespace.

Please fix your editor to show this type of thing in bright red so you
know not to include it.  It's all over this patch.

thanks.

greg k-h

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [Linux-kernel-mentees] [PATCH v3] Media: Radio: Change devm_k*alloc to k*alloc
@ 2019-06-18  6:10   ` Greg KH
  0 siblings, 0 replies; 4+ messages in thread
From: Greg KH @ 2019-06-18  6:10 UTC (permalink / raw)


On Mon, Jun 17, 2019 at 10:42:49PM -0700, Luke Nowakowski-Krijger wrote:
> Change devm_k*alloc to k*alloc to manually allocate memory. Memory is freed in v4l2.release callback which now calls raremono_device_release to free up the appropriate memory, just like in radio-shark driver. 

Please properly wrap your changelog text at 72 columns and do not add
trailing whitespace.

> 
> This patch aims to fix the use-after-free read described in
> https://syzkaller.appspot.com/bug?extid=a4387f5b6b799f6becbf

Does it?  Did you submit it to syzkaller and get any results?

There is a proper way to credit the tool as well, please do that.

> 
> Signed-off-by: Luke Nowakowski-Krijger <lnowakow at eng.ucsd.edu>
> ---
> diff --git a/drivers/media/radio/radio-raremono.c b/drivers/media/radio/radio-raremono.c
> index 5e782b3c2fa9..b467ad7fdd21 100644
> --- a/drivers/media/radio/radio-raremono.c
> +++ b/drivers/media/radio/radio-raremono.c
> @@ -271,6 +271,15 @@ static int vidioc_g_frequency(struct file *file, void *priv,
>         return 0;
>  }
>  
> +static void raremono_device_release(struct v4l2_device *v4l2_dev)
> +{
> +       struct raremono_device *radio = to_raremono_dev(v4l2_dev);
> +       

Trailing whitespace :(

Did you run your patch through checkpatch?

> +       kfree(radio->buffer);
> +       kfree(radio);
> +}
> +
> +
>  /* File system interface */
>  static const struct v4l2_file_operations usb_raremono_fops = {
>         .owner          = THIS_MODULE,
> @@ -295,12 +304,15 @@ static int usb_raremono_probe(struct usb_interface *intf,
>         struct raremono_device *radio;
>         int retval = 0;
>  
> -       radio = devm_kzalloc(&intf->dev, sizeof(struct raremono_device), GFP_KERNEL);
> -       if (radio)
> -               radio->buffer = devm_kmalloc(&intf->dev, BUFFER_LENGTH, GFP_KERNEL);
> -
> -       if (!radio || !radio->buffer)
> +       radio = kzalloc(sizeof(struct raremono_device), GFP_KERNEL);
> +       if (!radio)
>                 return -ENOMEM;
> +       

Trailing whitespace :(

> +       radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
> +       if (!radio->buffer) {
> +               kfree(radio);
> +               return -ENOMEM;
> +       }
>  
>         radio->usbdev = interface_to_usbdev(intf);
>         radio->intf = intf;
> @@ -324,7 +336,9 @@ static int usb_raremono_probe(struct usb_interface *intf,
>         if (retval != 3 ||
>             (get_unaligned_be16(&radio->buffer[1]) & 0xfff) == 0x0242) {
>                 dev_info(&intf->dev, "this is not Thanko's Raremono.\n");
> -               return -ENODEV;
> +               

More trailing whitespace.

Please fix your editor to show this type of thing in bright red so you
know not to include it.  It's all over this patch.

thanks.

greg k-h

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2019-06-18  6:10 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-06-18  5:42 [Linux-kernel-mentees] [PATCH v3] Media: Radio: Change devm_k*alloc to k*alloc lnowakow
2019-06-18  5:42 ` Luke Nowakowski-Krijger
2019-06-18  6:10 ` gregkh
2019-06-18  6:10   ` Greg KH

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