[patch] target: handle empty string writes in sysfs

[patch] target: handle empty string writes in sysfs

[Dan Carpenter]

These are root only and we're not likely to hit the problem in practise,
but it makes a the static checkers happy.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 0955bb8..9b86330 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1707,6 +1707,8 @@ static ssize_t target_core_store_dev_alias(
 	se_dev->su_dev_flags |= SDF_USING_ALIAS;
 	read_bytes = snprintf(&se_dev->se_dev_alias[0], SE_DEV_ALIAS_LEN,
 			"%s", page);
+	if (read_bytes == 0)
+		return -EINVAL;
 
 	if (se_dev->se_dev_alias[read_bytes - 1] == '\n')
 		se_dev->se_dev_alias[read_bytes - 1] = '\0';
@@ -1756,6 +1758,8 @@ static ssize_t target_core_store_dev_udev_path(
 	se_dev->su_dev_flags |= SDF_USING_UDEV_PATH;
 	read_bytes = snprintf(&se_dev->se_dev_udev_path[0], SE_UDEV_PATH_LEN,
 			"%s", page);
+	if (read_bytes == 0)
+		return -EINVAL;
 
 	if (se_dev->se_dev_udev_path[read_bytes - 1] == '\n')
 		se_dev->se_dev_udev_path[read_bytes - 1] = '\0';

Re: [patch] target: handle empty string writes in sysfs

[walter harms]

Am 24.01.2012 09:40, schrieb Dan Carpenter:
> These are root only and we're not likely to hit the problem in practise,
> but it makes a the static checkers happy.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
> index 0955bb8..9b86330 100644
> --- a/drivers/target/target_core_configfs.c
> +++ b/drivers/target/target_core_configfs.c
> @@ -1707,6 +1707,8 @@ static ssize_t target_core_store_dev_alias(
>  	se_dev->su_dev_flags |= SDF_USING_ALIAS;
>  	read_bytes = snprintf(&se_dev->se_dev_alias[0], SE_DEV_ALIAS_LEN,
>  			"%s", page);

Would it help to check page==NULL or *page==0 at start ?
Now you have se_dev->su_dev_flags initialised.

re,
 wh


> +	if (read_bytes == 0)
> +		return -EINVAL;
>  
>  	if (se_dev->se_dev_alias[read_bytes - 1] == '\n')
>  		se_dev->se_dev_alias[read_bytes - 1] = '\0';
> @@ -1756,6 +1758,8 @@ static ssize_t target_core_store_dev_udev_path(
>  	se_dev->su_dev_flags |= SDF_USING_UDEV_PATH;
>  	read_bytes = snprintf(&se_dev->se_dev_udev_path[0], SE_UDEV_PATH_LEN,
>  			"%s", page);
> +	if (read_bytes == 0)
> +		return -EINVAL;
>  
>  	if (se_dev->se_dev_udev_path[read_bytes - 1] == '\n')
>  		se_dev->se_dev_udev_path[read_bytes - 1] = '\0';
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

Re: [patch] target: handle empty string writes in sysfs

[Dan Carpenter]

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On Tue, Jan 24, 2012 at 11:55:45AM +0100, walter harms wrote:
> 
> 
> Am 24.01.2012 09:40, schrieb Dan Carpenter:
> > These are root only and we're not likely to hit the problem in practise,
> > but it makes a the static checkers happy.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
> > index 0955bb8..9b86330 100644
> > --- a/drivers/target/target_core_configfs.c
> > +++ b/drivers/target/target_core_configfs.c
> > @@ -1707,6 +1707,8 @@ static ssize_t target_core_store_dev_alias(
> >  	se_dev->su_dev_flags |= SDF_USING_ALIAS;
> >  	read_bytes = snprintf(&se_dev->se_dev_alias[0], SE_DEV_ALIAS_LEN,
> >  			"%s", page);
> 
> Would it help to check page==NULL or *page==0 at start ?
> Now you have se_dev->su_dev_flags initialised.

It's a fair point.  Let me redo it.

regards,
dan carpenter


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[patch v2] target: handle empty string writes in sysfs

[Dan Carpenter]

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These are root only and we're not likely to hit the problem in practise,
but it makes the static checkers happy.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: only set ->su_dev_flags on success.

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 0955bb8..6e043ee 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1704,13 +1704,15 @@ static ssize_t target_core_store_dev_alias(
 		return -EINVAL;
 	}
 
-	se_dev->su_dev_flags |= SDF_USING_ALIAS;
 	read_bytes = snprintf(&se_dev->se_dev_alias[0], SE_DEV_ALIAS_LEN,
 			"%s", page);
-
+	if (!read_bytes)
+		return -EINVAL;
 	if (se_dev->se_dev_alias[read_bytes - 1] == '\n')
 		se_dev->se_dev_alias[read_bytes - 1] = '\0';
 
+	se_dev->su_dev_flags |= SDF_USING_ALIAS;
+
 	pr_debug("Target_Core_ConfigFS: %s/%s set alias: %s\n",
 		config_item_name(&hba->hba_group.cg_item),
 		config_item_name(&se_dev->se_dev_group.cg_item),
@@ -1753,13 +1755,15 @@ static ssize_t target_core_store_dev_udev_path(
 		return -EINVAL;
 	}
 
-	se_dev->su_dev_flags |= SDF_USING_UDEV_PATH;
 	read_bytes = snprintf(&se_dev->se_dev_udev_path[0], SE_UDEV_PATH_LEN,
 			"%s", page);
-
+	if (!read_bytes)
+		return -EINVAL;
 	if (se_dev->se_dev_udev_path[read_bytes - 1] == '\n')
 		se_dev->se_dev_udev_path[read_bytes - 1] = '\0';
 
+	se_dev->su_dev_flags |= SDF_USING_UDEV_PATH;
+
 	pr_debug("Target_Core_ConfigFS: %s/%s set udev_path: %s\n",
 		config_item_name(&hba->hba_group.cg_item),
 		config_item_name(&se_dev->se_dev_group.cg_item),

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