Statistics->Flow Graph in qtshark crashes with a segfault

What appears to be happening is SequenceDiagram::draw() is iterating over the stored seq_analysis_item_t elements - but at the same time SequenceDialog::fillDiagram() is running - which destroys the old seq_analysis_info_t (which SequenceDiagram has stored a copy of and is referencing items in the list) then reloads it.

I'll attach a patch to SequenceDialog::fillDiagram() which fixes the problem - essentially calling sequence_analysis_list_get() with a new seq_analysis_info_t, calling SequenceDialog::setData() with the new one, then destroying the current seq_analysis_info_t and replacing it with the new on

Change-Id: I14f7b5dc64018ba5b81fe8d874a701e021401859
Closed-bug:9506
Reviewed-on: https://code.wireshark.org/review/175
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Alexis La Goutte <alexis.lagoutte@gmail.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/ui/qt/sequence_dialog.cpp b/ui/qt/sequence_dialog.cpp
index f814e1c5bd..3589765018 100644
--- a/ui/qt/sequence_dialog.cpp
+++ b/ui/qt/sequence_dialog.cpp
@@ -345,12 +345,17 @@ void SequenceDialog::on_buttonBox_accepted()
 void SequenceDialog::fillDiagram()
 {
     QCustomPlot *sp = ui->sequencePlot;
-
+    seq_analysis_info_t new_sa;
+
+    new_sa = seq_analysis_;
+    new_sa.list = NULL;
+    new_sa.ht = NULL;
+    new_sa.num_nodes = 0;
+    sequence_analysis_list_get(cap_file_, &new_sa);
+    num_items_ = sequence_analysis_get_nodes(&new_sa);
+    seq_diagram_->setData(&new_sa);
     sequence_analysis_list_free(&seq_analysis_);
-    sequence_analysis_list_get(cap_file_, &seq_analysis_);
-    num_items_ = sequence_analysis_get_nodes(&seq_analysis_);
-
-    seq_diagram_->setData(&seq_analysis_);
+    seq_analysis_ = new_sa;
 
     QFontMetrics vfm = QFontMetrics(sp->xAxis2->labelFont());
     node_label_w_ = 0;