diff mbox

[3/3] ima_fs: Move three error code assignments in ima_write_policy()

Message ID b6339fa4-69b3-afc4-18a8-254369fec074@users.sourceforge.net
State New, archived
Headers show

Commit Message

SF Markus Elfring Jan. 25, 2017, 9:34 a.m. UTC
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 24 Jan 2017 22:47:07 +0100

A local variable was set to an error code in three cases before a concrete
error situation was detected. Thus move the corresponding assignments into
if branches to indicate a software failure there.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 security/integrity/ima/ima_fs.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

Comments

Mimi Zohar Jan. 27, 2017, 12:39 p.m. UTC | #1
On Wed, 2017-01-25 at 10:34 +0100, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Tue, 24 Jan 2017 22:47:07 +0100
> 
> A local variable was set to an error code in three cases before a concrete
> error situation was detected. Thus move the corresponding assignments into
> if branches to indicate a software failure there.
> 
> This issue was detected by using the Coccinelle software.

This coding style was pretty common.  I assume the compiler is smart
enough to do the right thing.  Is this a FYI, letting us know for the
future the preferred coding style, or are we really upstreaming these
sorts of coding style changes?

Mimi

> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  security/integrity/ima/ima_fs.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
> index 98304411915d..a50c26f9772c 100644
> --- a/security/integrity/ima/ima_fs.c
> +++ b/security/integrity/ima/ima_fs.c
> @@ -317,21 +317,24 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf,
> 
>  	/* No partial writes. */
>  	result = -EINVAL;
> -	if (*ppos != 0)
> +	if (*ppos != 0) {
> +		result = -EINVAL;
>  		goto reset_validity;
> +	}
> 
> -	result = -ENOMEM;
>  	if (datalen >= PAGE_SIZE)
>  		datalen = PAGE_SIZE - 1;
>  	data = kmalloc(datalen + 1, GFP_KERNEL);
> -	if (!data)
> +	if (!data) {
> +		result = -ENOMEM;
>  		goto reset_validity;
> +	}
> 
>  	*(data + datalen) = '\0';
> -
> -	result = -EFAULT;
> -	if (copy_from_user(data, buf, datalen))
> +	if (copy_from_user(data, buf, datalen)) {
> +		result = -EFAULT;
>  		goto out_free;
> +	}
> 
>  	result = mutex_lock_interruptible(&ima_write_mutex);
>  	if (result < 0)


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James Morris Jan. 29, 2017, 11:43 p.m. UTC | #2
On Fri, 27 Jan 2017, Mimi Zohar wrote:

> On Wed, 2017-01-25 at 10:34 +0100, SF Markus Elfring wrote:
> > From: Markus Elfring <elfring@users.sourceforge.net>
> > Date: Tue, 24 Jan 2017 22:47:07 +0100
> > 
> > A local variable was set to an error code in three cases before a concrete
> > error situation was detected. Thus move the corresponding assignments into
> > if branches to indicate a software failure there.
> > 
> > This issue was detected by using the Coccinelle software.
> 
> This coding style was pretty common.  I assume the compiler is smart
> enough to do the right thing.  Is this a FYI, letting us know for the
> future the preferred coding style, or are we really upstreaming these
> sorts of coding style changes?

Nope, and I generally don't want cleanup patches from Markus going into 
the security tree.

See also:
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1254425.html


- James
diff mbox

Patch

diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 98304411915d..a50c26f9772c 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -317,21 +317,24 @@  static ssize_t ima_write_policy(struct file *file, const char __user *buf,
 
 	/* No partial writes. */
 	result = -EINVAL;
-	if (*ppos != 0)
+	if (*ppos != 0) {
+		result = -EINVAL;
 		goto reset_validity;
+	}
 
-	result = -ENOMEM;
 	if (datalen >= PAGE_SIZE)
 		datalen = PAGE_SIZE - 1;
 	data = kmalloc(datalen + 1, GFP_KERNEL);
-	if (!data)
+	if (!data) {
+		result = -ENOMEM;
 		goto reset_validity;
+	}
 
 	*(data + datalen) = '\0';
-
-	result = -EFAULT;
-	if (copy_from_user(data, buf, datalen))
+	if (copy_from_user(data, buf, datalen)) {
+		result = -EFAULT;
 		goto out_free;
+	}
 
 	result = mutex_lock_interruptible(&ima_write_mutex);
 	if (result < 0)