diff mbox

[1/2] tun: Use memdup_user() rather than duplicating its implementation

Message ID a2ee9925-1241-0328-6d35-9a9c9f567ea4@users.sourceforge.net
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

SF Markus Elfring Aug. 20, 2016, 7:34 a.m. UTC 
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 20 Aug 2016 08:54:15 +0200

Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/net/tun.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

Comments

Shmulik Ladkani Aug. 20, 2016, 11:47 a.m. UTC | #1 
Hi,

On Sat, 20 Aug 2016 09:34:56 +0200 SF Markus Elfring <elfring@users.sourceforge.net> wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 20 Aug 2016 08:54:15 +0200
> 
> Reuse existing functionality from memdup_user() instead of keeping
> duplicate source code.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Michael S. Tsirkin Aug. 22, 2016, 1:43 a.m. UTC | #2 
On Sat, Aug 20, 2016 at 09:34:56AM +0200, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 20 Aug 2016 08:54:15 +0200
> 
> Reuse existing functionality from memdup_user() instead of keeping
> duplicate source code.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>


Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  drivers/net/tun.c | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index 9c8b5bc..a1aeccb 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -731,14 +731,9 @@ static int update_filter(struct tap_filter *filter, void __user *arg)
>  	}
>  
>  	alen = ETH_ALEN * uf.count;
> -	addr = kmalloc(alen, GFP_KERNEL);
> -	if (!addr)
> -		return -ENOMEM;
> -
> -	if (copy_from_user(addr, arg + sizeof(uf), alen)) {
> -		err = -EFAULT;
> -		goto done;
> -	}
> +	addr = memdup_user(arg + sizeof(uf), alen);
> +	if (IS_ERR(addr))
> +		return PTR_ERR(addr);
>  
>  	/* The filter is updated without holding any locks. Which is
>  	 * perfectly safe. We disable it first and in the worst
> -- 
> 2.9.3
diff mbox

Patch

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9c8b5bc..a1aeccb 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -731,14 +731,9 @@  static int update_filter(struct tap_filter *filter, void __user *arg)
 	}
 
 	alen = ETH_ALEN * uf.count;
-	addr = kmalloc(alen, GFP_KERNEL);
-	if (!addr)
-		return -ENOMEM;
-
-	if (copy_from_user(addr, arg + sizeof(uf), alen)) {
-		err = -EFAULT;
-		goto done;
-	}
+	addr = memdup_user(arg + sizeof(uf), alen);
+	if (IS_ERR(addr))
+		return PTR_ERR(addr);
 
 	/* The filter is updated without holding any locks. Which is
 	 * perfectly safe. We disable it first and in the worst