From 846ac30135e7c5e03b487c16c87ccb1ab020a01f Mon Sep 17 00:00:00 2001
From: Tilman Schmidt <tilman@imap.cc>
Date: Sat, 11 Oct 2014 13:46:29 +0200
Subject: isdn/gigaset: fix NULL pointer dereference

In do_action, a NULL pointer might be passed to function start_dial
which will dereference it.
Fix by adding a check for NULL before the call.

Spotted with Coverity.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/isdn/gigaset/ev-layer.c b/drivers/isdn/gigaset/ev-layer.c
index dcae14a..0f699eb 100644
--- a/drivers/isdn/gigaset/ev-layer.c
+++ b/drivers/isdn/gigaset/ev-layer.c
@@ -1380,6 +1380,11 @@ static void do_action(int action, struct cardstate *cs,
 	/* events from the LL */
 
 	case ACT_DIAL:
+		if (!ev->ptr) {
+			*p_genresp = 1;
+			*p_resp_code = RSP_ERROR;
+			break;
+		}
 		start_dial(at_state, ev->ptr, ev->parameter);
 		break;
 	case ACT_ACCEPT:
-- 
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