From 057c147541bde6f0cbe22ca069b43a97ddc95baf Mon Sep 17 00:00:00 2001 From: Tiago Vignatti Date: Fri, 16 Apr 2010 18:01:41 +0300 Subject: [PATCH] Xi: check for NULL pointer before dereferences it in ListButtonInfo Both dev and dev->button are already used before their checking were being performed. So check on the beginning. Signed-off-by: Tiago Vignatti Reviewed-by: Peter Hutterer Reviewed-by: Dan Nicholson --- Xi/xiquerydevice.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/Xi/xiquerydevice.c b/Xi/xiquerydevice.c index 435868de2..47ab688fd 100644 --- a/Xi/xiquerydevice.c +++ b/Xi/xiquerydevice.c @@ -247,6 +247,9 @@ ListButtonInfo(DeviceIntPtr dev, xXIButtonInfo* info, Bool reportState) int mask_len; int i; + if (!dev || !dev->button) + return 0; + mask_len = bytes_to_int32(bits_to_bytes(dev->button->numButtons)); info->type = ButtonClass; @@ -259,7 +262,7 @@ ListButtonInfo(DeviceIntPtr dev, xXIButtonInfo* info, Bool reportState) memset(bits, 0, mask_len * 4); if (reportState) - for (i = 0; dev && dev->button && i < dev->button->numButtons; i++) + for (i = 0; i < dev->button->numButtons; i++) if (BitIsOn(dev->button->down, i)) SetBit(bits, i);