From a3161ae9a2ca58e7debcf08f0b8cada09429f147 Mon Sep 17 00:00:00 2001
From: iceman1001 <iceman@iuse.se>
Date: Thu, 19 Sep 2019 13:12:48 +0200
Subject: [PATCH] fix 'lf em 4x50_read - now checks if have enough data in
 Graphbuffer

---
 client/cmdlfem4x.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c
index b7948b14c..e7b1c2b06 100644
--- a/client/cmdlfem4x.c
+++ b/client/cmdlfem4x.c
@@ -821,6 +821,12 @@ int EM4x50Read(const char *Cmd, bool verbose) {
 
     uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0};
     size_t size = getFromGraphBuf(bits);
+
+    if (size < 4000) {
+       if (verbose || g_debugMode) PrintAndLogEx(ERR, "Error: EM4x50 - Too little data in Graphbuffer");
+       return PM3_ESOFT;
+    }
+
     computeSignalProperties(bits, size);
 
     signal_t *sp = getSignalProperties();