ipmi: ipmi_devintf: compat_ioctl method fails to take ipmi_mutex

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.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c
index 9eb360ff8cab0cc19178b6412ade5f4cf3d40e18..d5a5f020810afcdf8f6d5d19d1b45960c83589d5 100644 (file)
--- 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,