ATM: do not try to dissect if pseudo header is not present

Bug: 12013
Change-Id: If753fcdbb01d646fc4db43485549e8c6f668eced
Reviewed-on: https://code.wireshark.org/review/13311
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Reviewed-by: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/epan/dissectors/packet-atm.c b/epan/dissectors/packet-atm.c
index 381bd0dd93..c60bda7dbb 100644
--- a/epan/dissectors/packet-atm.c
+++ b/epan/dissectors/packet-atm.c
@@ -1644,6 +1644,10 @@ dissect_atm_truncated(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void
 {
   struct atm_phdr *atm_info = (struct atm_phdr *)data;
 
+  if (!atm_info) {
+    return 0;
+  }
+
   return dissect_atm_common(tvb, pinfo, tree, TRUE, atm_info, FALSE);
 }
 
@@ -1652,6 +1656,10 @@ dissect_atm_pw_truncated(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, vo
 {
   struct atm_phdr *atm_info = (struct atm_phdr *)data;
 
+  if (!atm_info) {
+    return 0;
+  }
+
   return dissect_atm_common(tvb, pinfo, tree, TRUE, atm_info, TRUE);
 }
 
@@ -1660,6 +1668,10 @@ dissect_atm_untruncated(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, voi
 {
   struct atm_phdr *atm_info = (struct atm_phdr *)data;
 
+  if (!atm_info) {
+    return 0;
+  }
+
   return dissect_atm_common(tvb, pinfo, tree, FALSE, atm_info, FALSE);
 }
 
@@ -1668,6 +1680,10 @@ dissect_atm_pw_untruncated(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 {
   struct atm_phdr *atm_info = (struct atm_phdr *)data;
 
+  if (!atm_info) {
+    return 0;
+  }
+
   return dissect_atm_common(tvb, pinfo, tree, FALSE, atm_info, TRUE);
 }