[PATCH 3/3] scsi: myrs: prevent negatives in disable_enclosure_messages_store()

[PATCH 3/3] scsi: myrs: prevent negatives in disable_enclosure_messages_store()

[Dan Carpenter]

We only want the value to be zero or one.

It's not a big deal, but say we passed set value to INT_MIN, then
disable_enclosure_messages_show() would return that 12 bytes of "buf"
are initialized but actually only 3 are.  I think there are tools like
KASAN which will trigger an info leak warning when that happens.

Fixes: 77266186397c ("scsi: myrs: Add Mylex RAID controller (SCSI interface)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/scsi/myrs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/myrs.c b/drivers/scsi/myrs.c
index 07e5a3f54e31..55842ed54231 100644
--- a/drivers/scsi/myrs.c
+++ b/drivers/scsi/myrs.c
@@ -1501,7 +1501,7 @@ static ssize_t disable_enclosure_messages_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	if (value > 2)
+	if (value < 0 || value > 2)
 		return -EINVAL;
 
 	cs->disable_enc_msg = value;
-- 
2.11.0

Re: [PATCH 3/3] scsi: myrs: prevent negatives in disable_enclosure_messages_store()

[Martin K. Petersen]

Dan,

> We only want the value to be zero or one.
>
> It's not a big deal, but say we passed set value to INT_MIN, then
> disable_enclosure_messages_show() would return that 12 bytes of "buf"
> are initialized but actually only 3 are.  I think there are tools like
> KASAN which will trigger an info leak warning when that happens.

s/kstrtoint/kstrtouint/?

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 3/3] scsi: myrs: prevent negatives in disable_enclosure_messages_store()

[Dan Carpenter]

On Fri, Oct 19, 2018 at 12:19:09PM +0300, Dan Carpenter wrote:
> We only want the value to be zero or one.
> 
> It's not a big deal, but say we passed set value to INT_MIN, then
> disable_enclosure_messages_show() would return that 12 bytes of "buf"
> are initialized but actually only 3 are.  I think there are tools like
> KASAN which will trigger an info leak warning when that happens.
> 
> Fixes: 77266186397c ("scsi: myrs: Add Mylex RAID controller (SCSI interface)")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  drivers/scsi/myrs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/myrs.c b/drivers/scsi/myrs.c
> index 07e5a3f54e31..55842ed54231 100644
> --- a/drivers/scsi/myrs.c
> +++ b/drivers/scsi/myrs.c
> @@ -1501,7 +1501,7 @@ static ssize_t disable_enclosure_messages_store(struct device *dev,
>  	if (ret)
>  		return ret;
>  
> -	if (value > 2)
> +	if (value < 0 || value > 2)
>  		return -EINVAL;

It's not actually clear to me why we allow 2.  Shouldn't we just use
kstrtobool()?

regards,
dan carpenter

Re: [PATCH 3/3] scsi: myrs: prevent negatives in disable_enclosure_messages_store()

[Martin K. Petersen]

Dan,

>> +	if (value < 0 || value > 2)
>>  		return -EINVAL;
>
> It's not actually clear to me why we allow 2.  Shouldn't we just use
> kstrtobool()?

Hannes?

-- 
Martin K. Petersen	Oracle Linux Engineering