From 022ba32c1ab58ff6935c8f147f5cfe247cb5402d Mon Sep 17 00:00:00 2001
From: "Markus F.X.J. Oberhumer" <markus@oberhumer.com>
Date: Thu, 6 Oct 2016 12:11:32 +0200
Subject: [PATCH] Improve robustness of seek() by adding some sanity checks.

---
 src/file.cpp | 12 ++++++++----
 src/file.h   |  6 +++---
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/file.cpp b/src/file.cpp
index c2752624..b6042017 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -168,8 +168,10 @@ void FileBase::write(const void *buf, int len)
 }
 
 
-off_t FileBase::seek(off_t off, int whence)
+off_t FileBase::seek(upx_int64_t off64, int whence)
 {
+    (void) mem_size(1, off64 >= 0 ? off64 : -off64); // sanity check
+    off_t off = ACC_ICONV(off_t, off64);
     if (!isOpen())
         throwIOException("bad seek 1");
     if (whence == SEEK_SET) {
@@ -285,9 +287,9 @@ int InputFile::readx(MemBuffer &buf, int len)
 }
 
 
-off_t InputFile::seek(off_t off, int whence)
+off_t InputFile::seek(upx_int64_t off64, int whence)
 {
-    off_t pos = super::seek(off,whence);
+    off_t pos = super::seek(off64, whence);
     if (_length < pos)
         throwIOException("bad seek 4");
     return pos;
@@ -402,8 +404,10 @@ void OutputFile::rewrite(const void *buf, int len)
     bytes_written -= len;       // restore
 }
 
-off_t OutputFile::seek(off_t off, int whence)
+off_t OutputFile::seek(upx_int64_t off64, int whence)
 {
+    (void) mem_size(1, off64 >= 0 ? off64 : -off64); // sanity check
+    off_t off = ACC_ICONV(off_t, off64);
     assert(!opt->to_stdout);
     switch (whence) {
     case SEEK_SET: {
diff --git a/src/file.h b/src/file.h
index d895efd6..0ddd84a6 100644
--- a/src/file.h
+++ b/src/file.h
@@ -67,7 +67,7 @@ protected:
     virtual int read(void *buf, int len);
     virtual int readx(void *buf, int len);
     virtual void write(const void *buf, int len);
-    virtual off_t seek(off_t off, int whence);
+    virtual off_t seek(upx_int64_t off, int whence);
     virtual off_t tell() const;
 
     int _fd;
@@ -106,7 +106,7 @@ public:
     virtual int read(MemBuffer &buf, int len);
     virtual int readx(MemBuffer &buf, int len);
 
-    virtual off_t seek(off_t off, int whence);
+    virtual off_t seek(upx_int64_t off, int whence);
     virtual off_t tell() const;
     virtual off_t st_size_orig() const;
 protected:
@@ -142,7 +142,7 @@ public:
     virtual off_t st_size() const;  // { return _length; }
 
     // FIXME - these won't work when using the '--stdout' option
-    virtual off_t seek(off_t off, int whence);
+    virtual off_t seek(upx_int64_t off, int whence);
     virtual void rewrite(const void *buf, int len);
 
     // util