From 87dba497998a5c33b6780dca0cc128b0aaa27ce4 Mon Sep 17 00:00:00 2001
From: Fabrice Desclaux <fabrice.desclaux@cea.fr>
Date: Mon, 25 Nov 2019 21:30:31 +0100
Subject: [PATCH] PE: API returns None on bad traduction addreses

---
 miasm/jitter/loader/pe.py |  8 ++++++--
 miasm/loader/pe_init.py   | 24 ++++++++++++++++++------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/miasm/jitter/loader/pe.py b/miasm/jitter/loader/pe.py
index 9bd488773..02558e6c3 100644
--- a/miasm/jitter/loader/pe.py
+++ b/miasm/jitter/loader/pe.py
@@ -323,8 +323,12 @@ def vm2pe(myjit, fname, libs=None, e_orig=None,
     addrs = list(all_mem)
     addrs.sort()
     entry_point = mye.virt2rva(myjit.pc)
-    if not 0 < entry_point < 0xFFFFFFFF:
-        raise ValueError("Cannot compute a valid entry point RVA")
+    if entry_point is None or not 0 < entry_point < 0xFFFFFFFF:
+        raise ValueError(
+            "Current pc (0x%x) used as entry point seems to be out of the binary" %
+            myjit.pc
+        )
+
     mye.Opthdr.AddressOfEntryPoint = entry_point
     first = True
     for ad in addrs:
diff --git a/miasm/loader/pe_init.py b/miasm/loader/pe_init.py
index 74192849e..f5baa9a51 100644
--- a/miasm/loader/pe_init.py
+++ b/miasm/loader/pe_init.py
@@ -476,18 +476,30 @@ def off2rva(self, off):
             return
         return off - section.offset + section.addr
 
-    def virt2rva(self, virt):
-        if virt is None:
-            return
-        return virt - self.NThdr.ImageBase
+    def virt2rva(self, addr):
+        """
+        Return rva of virtual address @addr; None if addr is below ImageBase
+        """
+        if addr is None:
+            return None
+        rva = addr - self.NThdr.ImageBase
+        if rva < 0:
+            return None
+        return rva
 
     def rva2virt(self, rva):
         if rva is None:
             return
         return rva + self.NThdr.ImageBase
 
-    def virt2off(self, virt):
-        return self.rva2off(self.virt2rva(virt))
+    def virt2off(self, addr):
+        """
+        Return offset of virtual address @addr
+        """
+        rva = self.virt2rva(addr)
+        if rva is None:
+            return None
+        return self.rva2off(rva)
 
     def off2virt(self, off):
         return self.rva2virt(self.off2rva(off))