From 182248f364e6375eaad30cefdd6b67660abaa3b3 Mon Sep 17 00:00:00 2001
From: Alan Jowett <alan.jowett@microsoft.com>
Date: Fri, 19 Jan 2024 09:23:48 -0800
Subject: [PATCH] Validate size of entries before accessing members

Signed-off-by: Alan Jowett <alan.jowett@microsoft.com>
---
 elfio/elfio_relocation.hpp | 25 +++++++++++++++++--------
 elfio/elfio_symbols.hpp    |  3 +++
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/elfio/elfio_relocation.hpp b/elfio/elfio_relocation.hpp
index 2f39a36..1da8c92 100644
--- a/elfio/elfio_relocation.hpp
+++ b/elfio/elfio_relocation.hpp
@@ -96,26 +96,26 @@ template <class S> class relocation_section_accessor_template
 
         if ( elf_file.get_class() == ELFCLASS32 ) {
             if ( SHT_REL == relocation_section->get_type() ) {
-                generic_get_entry_rel<Elf32_Rel>( index, offset, symbol, type,
+                return generic_get_entry_rel<Elf32_Rel>( index, offset, symbol, type,
                                                   addend );
             }
             else if ( SHT_RELA == relocation_section->get_type() ) {
-                generic_get_entry_rela<Elf32_Rela>( index, offset, symbol, type,
+                return generic_get_entry_rela<Elf32_Rela>( index, offset, symbol, type,
                                                     addend );
             }
         }
         else {
             if ( SHT_REL == relocation_section->get_type() ) {
-                generic_get_entry_rel<Elf64_Rel>( index, offset, symbol, type,
+                return generic_get_entry_rel<Elf64_Rel>( index, offset, symbol, type,
                                                   addend );
             }
             else if ( SHT_RELA == relocation_section->get_type() ) {
-                generic_get_entry_rela<Elf64_Rela>( index, offset, symbol, type,
+                return generic_get_entry_rela<Elf64_Rela>( index, offset, symbol, type,
                                                     addend );
             }
         }
-
-        return true;
+        // Unknown relocation section type.
+        return false;
     }
 
     //------------------------------------------------------------------------------
@@ -319,7 +319,7 @@ template <class S> class relocation_section_accessor_template
 
     //------------------------------------------------------------------------------
     template <class T>
-    void generic_get_entry_rel( Elf_Xword   index,
+    bool generic_get_entry_rel( Elf_Xword   index,
                                 Elf64_Addr& offset,
                                 Elf_Word&   symbol,
                                 unsigned&   type,
@@ -327,6 +327,9 @@ template <class S> class relocation_section_accessor_template
     {
         const endianess_convertor& convertor = elf_file.get_convertor();
 
+        if (relocation_section->get_entry_size() < sizeof( T ) ) {
+            return false;
+        }
         const T* pEntry = reinterpret_cast<const T*>(
             relocation_section->get_data() +
             index * relocation_section->get_entry_size() );
@@ -335,11 +338,12 @@ template <class S> class relocation_section_accessor_template
         symbol        = get_sym_and_type<T>::get_r_sym( tmp );
         type          = get_sym_and_type<T>::get_r_type( tmp );
         addend        = 0;
+        return true;
     }
 
     //------------------------------------------------------------------------------
     template <class T>
-    void generic_get_entry_rela( Elf_Xword   index,
+    bool generic_get_entry_rela( Elf_Xword   index,
                                  Elf64_Addr& offset,
                                  Elf_Word&   symbol,
                                  unsigned&   type,
@@ -347,6 +351,10 @@ template <class S> class relocation_section_accessor_template
     {
         const endianess_convertor& convertor = elf_file.get_convertor();
 
+        if (relocation_section->get_entry_size() < sizeof( T ) ) {
+            return false;
+        }
+
         const T* pEntry = reinterpret_cast<const T*>(
             relocation_section->get_data() +
             index * relocation_section->get_entry_size() );
@@ -355,6 +363,7 @@ template <class S> class relocation_section_accessor_template
         symbol        = get_sym_and_type<T>::get_r_sym( tmp );
         type          = get_sym_and_type<T>::get_r_type( tmp );
         addend        = convertor( pEntry->r_addend );
+        return true;
     }
 
     //------------------------------------------------------------------------------
diff --git a/elfio/elfio_symbols.hpp b/elfio/elfio_symbols.hpp
index d868500..71b240a 100644
--- a/elfio/elfio_symbols.hpp
+++ b/elfio/elfio_symbols.hpp
@@ -395,6 +395,9 @@ template <class S> class symbol_section_accessor_template
     template <class T> const T* generic_get_symbol_ptr( Elf_Xword index ) const
     {
         if ( 0 != symbol_section->get_data() && index < get_symbols_num() ) {
+            if ( symbol_section->get_entry_size() < sizeof( T ) ) {
+                return nullptr;
+            }
             const T* pSym = reinterpret_cast<const T*>(
                 symbol_section->get_data() +
                 index * symbol_section->get_entry_size() );