Xi: Unify checking for invalid bits in grab masks.

Bits above XI2LASTEVENT are invalid and cause in BadValues. These checks
must be performed anywhere where a mask_len parameter is given.

This patch also adds the missing checks to grab masks.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

1 files changed, 3 insertions, 9 deletions

diff --git a/Xi/xipassivegrab.c b/Xi/xipassivegrab.c
index 0cfdc1d9b..41a56b14e 100644
--- a/Xi/xipassivegrab.c
+++ b/Xi/xipassivegrab.c
@@ -118,15 +118,9 @@ ProcXIPassiveGrabDevice(ClientPtr client)
         return BadValue;
     }
 
-    if ((stuff->mask_len * 4) > XI2LASTEVENT)
-    {
-        unsigned char *bits = (unsigned char*)&stuff[1];
-        for (i = XI2LASTEVENT; i < stuff->mask_len * 4; i++)
-        {
-            if (BitIsOn(bits, i))
-                return BadValue;
-        }
-    }
+    if (XICheckInvalidMaskBits((unsigned char*)&stuff[1],
+                               stuff->mask_len * 4) != Success)
+        return BadValue;
 
     mask_len = min(sizeof(mask.xi2mask[stuff->deviceid]), stuff->mask_len * 4);
     memset(mask.xi2mask, 0, sizeof(mask.xi2mask));