ipmi: ipmi_devintf: compat_ioctl method fails to take ipmi_mutex

commit 6368087e851e697679af059b4247aca33a69cef3 upstream.

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c
index 2aa3977aae5e35d28f897416d89e53731a5c38ee..8dde1f58ef6f02dc82abb2d04ef4a53f4eba8ffc 100644 (file)
--- a/drivers/char/ipmi/ipmi_devintf.c
+++ b/drivers/char/ipmi/ipmi_devintf.c
@@ -838,13 +838,25 @@ 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,