[PATCH] ipmi: ipmi_devintf: compat_ioctl method failes to take ipmi_mutex

[PATCH] ipmi: ipmi_devintf: compat_ioctl method failes to take ipmi_mutex

[Benjamin LaHaise]

When a 32 bit version of ipmitool is used on a 64 bit kernel, the
ipmi_devintf code fails to correctly acquire ipmi_mutex.  This results in
incomplete data being retrieved in some cases, or other possible failures.
Add a wrapper around compat_ipmi_ioctl() to take ipmi_mutex to fix this.
This is probably a candidate for -stable as well.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
---
 drivers/char/ipmi/ipmi_devintf.c |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c
index 9eb360f..d5a5f02 100644
--- a/drivers/char/ipmi/ipmi_devintf.c
+++ b/drivers/char/ipmi/ipmi_devintf.c
@@ -837,13 +837,25 @@ static long compat_ipmi_ioctl(struct file *filep, unsigned int cmd,
 		return ipmi_ioctl(filep, cmd, arg);
 	}
 }
+
+static long unlocked_compat_ipmi_ioctl(struct file *filep, unsigned int cmd,
+				       unsigned long arg)
+{
+	int ret;
+
+	mutex_lock(&ipmi_mutex);
+	ret = compat_ipmi_ioctl(filep, cmd, arg);
+	mutex_unlock(&ipmi_mutex);
+
+	return ret;
+}
 #endif
 
 static const struct file_operations ipmi_fops = {
 	.owner		= THIS_MODULE,
 	.unlocked_ioctl	= ipmi_unlocked_ioctl,
 #ifdef CONFIG_COMPAT
-	.compat_ioctl   = compat_ipmi_ioctl,
+	.compat_ioctl   = unlocked_compat_ipmi_ioctl,
 #endif
 	.open		= ipmi_open,
 	.release	= ipmi_release,
-- 
1.7.4.1


-- 
"Thought is the essence of where you are now."

Re: [PATCH] ipmi: ipmi_devintf: compat_ioctl method failes to take ipmi_mutex

[Corey Minyard]

Yes, you are right.  I've pulled this in to my tree.  Looking at this, 
ipmi_mutex really should go away and be replaced bu something that 
scales better, but I guess it's not that critical for IPMI.

-corey

On 05/13/2013 02:39 PM, Benjamin LaHaise wrote:
> When a 32 bit version of ipmitool is used on a 64 bit kernel, the
> ipmi_devintf code fails to correctly acquire ipmi_mutex.  This results in
> incomplete data being retrieved in some cases, or other possible failures.
> Add a wrapper around compat_ipmi_ioctl() to take ipmi_mutex to fix this.
> This is probably a candidate for -stable as well.
>
> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
> ---
>   drivers/char/ipmi/ipmi_devintf.c |   14 +++++++++++++-
>   1 files changed, 13 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c
> index 9eb360f..d5a5f02 100644
> --- a/drivers/char/ipmi/ipmi_devintf.c
> +++ b/drivers/char/ipmi/ipmi_devintf.c
> @@ -837,13 +837,25 @@ static long compat_ipmi_ioctl(struct file *filep, unsigned int cmd,
>   		return ipmi_ioctl(filep, cmd, arg);
>   	}
>   }
> +
> +static long unlocked_compat_ipmi_ioctl(struct file *filep, unsigned int cmd,
> +				       unsigned long arg)
> +{
> +	int ret;
> +
> +	mutex_lock(&ipmi_mutex);
> +	ret = compat_ipmi_ioctl(filep, cmd, arg);
> +	mutex_unlock(&ipmi_mutex);
> +
> +	return ret;
> +}
>   #endif
>   
>   static const struct file_operations ipmi_fops = {
>   	.owner		= THIS_MODULE,
>   	.unlocked_ioctl	= ipmi_unlocked_ioctl,
>   #ifdef CONFIG_COMPAT
> -	.compat_ioctl   = compat_ipmi_ioctl,
> +	.compat_ioctl   = unlocked_compat_ipmi_ioctl,
>   #endif
>   	.open		= ipmi_open,
>   	.release	= ipmi_release,