From 1bb0fa1809c781e1de9dcae8ee3e6089cf40f799 Mon Sep 17 00:00:00 2001
From: "Markus F.X.J. Oberhumer" <markus@oberhumer.com>
Date: Wed, 21 Sep 2016 00:35:51 +0200
Subject: [PATCH] Fix a few things spotted by the gcc-6 sanitizer. Needs
 review.

---
 src/linker.cpp   | 3 ++-
 src/p_lx_elf.cpp | 6 ++++++
 src/p_unix.cpp   | 2 +-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/linker.cpp b/src/linker.cpp
index 9fcb5c98..3ddedb44 100644
--- a/src/linker.cpp
+++ b/src/linker.cpp
@@ -69,7 +69,8 @@ ElfLinker::Section::Section(const char *n, const void *i, unsigned s, unsigned a
     assert(name != NULL);
     input = malloc(s + 1);
     assert(input != NULL);
-    memcpy(input, i, s);
+    if (s != 0)
+        memcpy(input, i, s);
     ((char *)input)[s] = 0;
 }
 
diff --git a/src/p_lx_elf.cpp b/src/p_lx_elf.cpp
index 39e711be..afb74677 100644
--- a/src/p_lx_elf.cpp
+++ b/src/p_lx_elf.cpp
@@ -230,6 +230,7 @@ PackLinuxElf32::PackLinuxElf32help1(InputFile *f)
 
     if (f && Elf32_Ehdr::ET_DYN!=e_type) {
         unsigned const len = sz_phdrs + e_phoff;
+        assert(file_image == NULL);
         file_image = New(char, len);
         f->seek(0, SEEK_SET);
         f->readx(file_image, len);
@@ -237,6 +238,7 @@ PackLinuxElf32::PackLinuxElf32help1(InputFile *f)
     }
     if (f && Elf32_Ehdr::ET_DYN==e_type) {
         // The DT_STRTAB has no designated length.  Read the whole file.
+        assert(file_image == NULL);
         file_image = New(char, file_size);
         f->seek(0, SEEK_SET);
         f->readx(file_image, file_size);
@@ -600,6 +602,7 @@ PackLinuxElf64::PackLinuxElf64help1(InputFile *f)
 
     if (f && Elf64_Ehdr::ET_DYN!=e_type) {
         unsigned const len = sz_phdrs + e_phoff;
+        assert(file_image == NULL);
         file_image = New(char, len);
         f->seek(0, SEEK_SET);
         f->readx(file_image, len);
@@ -607,6 +610,7 @@ PackLinuxElf64::PackLinuxElf64help1(InputFile *f)
     }
     if (f && Elf64_Ehdr::ET_DYN==e_type) {
         // The DT_STRTAB has no designated length.  Read the whole file.
+        assert(file_image == NULL);
         file_image = New(char, file_size);
         f->seek(0, SEEK_SET);
         f->readx(file_image, file_size);
@@ -1662,6 +1666,7 @@ PackLinuxElf64ppcle::canPack()
 
     if (Elf32_Ehdr::ET_DYN==get_te16(&ehdr->e_type)) {
         // The DT_STRTAB has no designated length.  Read the whole file.
+        assert(file_image == NULL);
         file_image = New(char, file_size);
         fi->seek(0, SEEK_SET);
         fi->readx(file_image, file_size);
@@ -1837,6 +1842,7 @@ PackLinuxElf64amd::canPack()
 
     if (Elf32_Ehdr::ET_DYN==get_te16(&ehdr->e_type)) {
         // The DT_STRTAB has no designated length.  Read the whole file.
+        assert(file_image == NULL);
         file_image = New(char, file_size);
         fi->seek(0, SEEK_SET);
         fi->readx(file_image, file_size);
diff --git a/src/p_unix.cpp b/src/p_unix.cpp
index 9c6fd5c2..a12f7863 100644
--- a/src/p_unix.cpp
+++ b/src/p_unix.cpp
@@ -325,7 +325,7 @@ void PackUnix::packExtent(
     }
     fi->seek(x.offset, SEEK_SET);
     for (off_t rest = x.size; 0 != rest; ) {
-        int const filter_strategy = getStrategy(*ft);
+        int const filter_strategy = ft ? getStrategy(*ft) : 0;
         int l = fi->readx(ibuf, UPX_MIN(rest, (off_t)blocksize));
         if (l == 0) {
             break;