hexdiff() - check input length

Author: guedou

scapy/utils.py

@@ -455,7 +455,7 @@ def hexdiff(a, b, autojunk=False):
 
         cl = ""
         for j in range(16):
-            if i + j < btx_len:
+            if i + j < min(len(backtrackx), len(backtracky)):
                 if line[j]:
                     col = colorize[(linex[j] != liney[j]) * (doy - dox)]
                     print(col("%02X" % orb(line[j])), end=' ')

test/regression.uts

@@ -772,6 +772,11 @@ assert ret1 != ret2
 assert expected_ret1 in ret1
 assert expected_ret2 in ret2
 
+# Test corner cases that should not crash
+
+hexdiff(b"abc", IP() / TCP())
+hexdiff(IP() / TCP(), b"abc")
+
 = Test mysummary functions - Ether
 
 p = Ether(dst="ff:ff:ff:ff:ff:ff", src="ff:ff:ff:ff:ff:ff", type=0x9000)