As struct iw_point is bi-directional payload, we should copy back the content

on return from ioctl calls

Signed-off-by: Masakazu Mokuno <mokuno@sm.sony.co.jp>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index a6c9078af124..5a5b7116cefb 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -2311,8 +2311,10 @@ static int do_wireless_ioctl(unsigned int fd, unsigned int cmd, unsigned long ar
         struct iwreq __user *iwr_u;
         struct iw_point __user *iwp;
         struct compat_iw_point __user *iwp_u;
-        compat_caddr_t pointer;
+        compat_caddr_t pointer_u;
+        void __user *pointer;
         __u16 length, flags;
+        int ret;
 
         iwr_u = compat_ptr(arg);
         iwp_u = (struct compat_iw_point __user *) &iwr_u->u.data;
@@ -2330,17 +2332,29 @@ static int do_wireless_ioctl(unsigned int fd, unsigned int cmd, unsigned long ar
                            sizeof(iwr->ifr_ifrn.ifrn_name)))
                 return -EFAULT;
 
-        if (__get_user(pointer, &iwp_u->pointer) ||
+        if (__get_user(pointer_u, &iwp_u->pointer) ||
             __get_user(length, &iwp_u->length) ||
             __get_user(flags, &iwp_u->flags))
                 return -EFAULT;
 
-        if (__put_user(compat_ptr(pointer), &iwp->pointer) ||
+        if (__put_user(compat_ptr(pointer_u), &iwp->pointer) ||
             __put_user(length, &iwp->length) ||
             __put_user(flags, &iwp->flags))
                 return -EFAULT;
 
-        return sys_ioctl(fd, cmd, (unsigned long) iwr);
+        ret = sys_ioctl(fd, cmd, (unsigned long) iwr);
+
+        if (__get_user(pointer, &iwp->pointer) ||
+            __get_user(length, &iwp->length) ||
+            __get_user(flags, &iwp->flags))
+                return -EFAULT;
+
+        if (__put_user(ptr_to_compat(pointer), &iwp_u->pointer) ||
+            __put_user(length, &iwp_u->length) ||
+            __put_user(flags, &iwp_u->flags))
+                return -EFAULT;
+
+        return ret;
 }
 
 /* Since old style bridge ioctl's endup using SIOCDEVPRIVATE