staging: wlan-ng: Fixed incorrect type warning in p80211netdev.c
diff mbox series

Message ID 20210217154255.112115-1-pritthijit.nath@icloud.com
State Accepted
Commit 5bc510b23e78baedc09fc471fcb3618639539c84
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Series
  • staging: wlan-ng: Fixed incorrect type warning in p80211netdev.c
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Commit Message

Pritthijit Nath Feb. 17, 2021, 3:42 p.m. UTC
This change fixes a sparse warning "incorrect type in argument 1
(different address spaces)".

Signed-off-by: Pritthijit Nath <pritthijit.nath@icloud.com>
---
 drivers/staging/wlan-ng/p80211netdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Greg Kroah-Hartman Feb. 17, 2021, 3:53 p.m. UTC | #1
On Wed, Feb 17, 2021 at 09:12:55PM +0530, Pritthijit Nath wrote:
> This change fixes a sparse warning "incorrect type in argument 1
> (different address spaces)".
> 
> Signed-off-by: Pritthijit Nath <pritthijit.nath@icloud.com>
> ---
>  drivers/staging/wlan-ng/p80211netdev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
> index 6f9666dc0277..70570e8a5ad2 100644
> --- a/drivers/staging/wlan-ng/p80211netdev.c
> +++ b/drivers/staging/wlan-ng/p80211netdev.c
> @@ -569,7 +569,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
>  		goto bail;
>  	}
>  
> -	msgbuf = memdup_user(req->data, req->len);
> +	msgbuf = memdup_user((void __user *)req->data, req->len);

Odd.  Why isn't data tagged as a __user pointer to start with?

thanks,

greg k-h
Pritthijit Nath Feb. 17, 2021, 4:27 p.m. UTC | #2
On 17/02/21 9:23 pm, Greg KH wrote:
> On Wed, Feb 17, 2021 at 09:12:55PM +0530, Pritthijit Nath wrote:
>> This change fixes a sparse warning "incorrect type in argument 1
>> (different address spaces)".
>>
>> Signed-off-by: Pritthijit Nath <pritthijit.nath@icloud.com>
>> ---
>>  drivers/staging/wlan-ng/p80211netdev.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
>> index 6f9666dc0277..70570e8a5ad2 100644
>> --- a/drivers/staging/wlan-ng/p80211netdev.c
>> +++ b/drivers/staging/wlan-ng/p80211netdev.c
>> @@ -569,7 +569,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
>>  		goto bail;
>>  	}
>>  
>> -	msgbuf = memdup_user(req->data, req->len);
>> +	msgbuf = memdup_user((void __user *)req->data, req->len);
> 
> Odd.  Why isn't data tagged as a __user pointer to start with?
> 
> thanks,
> 
> greg k-h
> 

In lines 540-548 ->

...

static int p80211knetdev_do_ioctl(struct net_device *dev,
                                  struct ifreq *ifr, int cmd)
{
        int result = 0;
        struct p80211ioctl_req *req = (struct p80211ioctl_req *)ifr;
        struct wlandevice *wlandev = dev->ml_priv;
        u8 *msgbuf;

        netdev_dbg(dev, "rx'd ioctl, cmd=%d, len=%d\n", cmd, req->len);

...

it can be seen that *req is essentially coming from an explicit cast of *ifr. ifr->data itself is of char* type. So, imo, an explicit __user pointer cast is required. 

The patch above was based on the __user pointer cast done in lines 580-586 ->

...

if (result == 0) {
                if (copy_to_user
                    ((void __user *)req->data, msgbuf, req->len)) {
                        result = -EFAULT;
                }
        }
        kfree(msgbuf);

...

and lines 550-556 ->

#ifdef SIOCETHTOOL
        if (cmd == SIOCETHTOOL) {
                result =
                    p80211netdev_ethtool(wlandev, (void __user *)ifr->ifr_data);
                goto bail;
        }
#endif
Dan Carpenter Feb. 18, 2021, 12:04 p.m. UTC | #3
On Wed, Feb 17, 2021 at 09:12:55PM +0530, Pritthijit Nath wrote:
> This change fixes a sparse warning "incorrect type in argument 1
> (different address spaces)".
> 
> Signed-off-by: Pritthijit Nath <pritthijit.nath@icloud.com>
> ---
>  drivers/staging/wlan-ng/p80211netdev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
> index 6f9666dc0277..70570e8a5ad2 100644
> --- a/drivers/staging/wlan-ng/p80211netdev.c
> +++ b/drivers/staging/wlan-ng/p80211netdev.c
> @@ -569,7 +569,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
>  		goto bail;
>  	}
>  
> -	msgbuf = memdup_user(req->data, req->len);
> +	msgbuf = memdup_user((void __user *)req->data, req->len);

Probably the correct fix is to just change the type of
(struct p80211ioctl_req)->data from caddr_t to "void __user *data;".

I haven't looked at this though, so double check.

regards,
dan carpenter
Ivan Safonov Feb. 19, 2021, 7:37 a.m. UTC | #4
On 2/17/21 6:42 PM, pritthijit.nath at icloud.com (Pritthijit Nath) wrote:
> This change fixes a sparse warning "incorrect type in argument 1
> (different address spaces)".
> 
> Signed-off-by: Pritthijit Nath <pritthijit.nath at icloud.com>
> ---
>   drivers/staging/wlan-ng/p80211netdev.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
> index 6f9666dc0277..70570e8a5ad2 100644
> --- a/drivers/staging/wlan-ng/p80211netdev.c
> +++ b/drivers/staging/wlan-ng/p80211netdev.c
> @@ -569,7 +569,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
>                  goto bail;
>          }
>   
> -       msgbuf = memdup_user(req->data, req->len);
> +       msgbuf = memdup_user((void __user *)req->data, req->len);
>          if (IS_ERR(msgbuf)) {
>                  result = PTR_ERR(msgbuf);
>                  goto bail;
> 

Reviewed-by: Ivan Safonov <insafonov@gmail.com>

Patch
diff mbox series

diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
index 6f9666dc0277..70570e8a5ad2 100644
--- a/drivers/staging/wlan-ng/p80211netdev.c
+++ b/drivers/staging/wlan-ng/p80211netdev.c
@@ -569,7 +569,7 @@  static int p80211knetdev_do_ioctl(struct net_device *dev,
 		goto bail;
 	}
 
-	msgbuf = memdup_user(req->data, req->len);
+	msgbuf = memdup_user((void __user *)req->data, req->len);
 	if (IS_ERR(msgbuf)) {
 		result = PTR_ERR(msgbuf);
 		goto bail;