[PATCH] D25015: [Object/ELF] - Report error on incorrect sh_offset.

[George Rimar via llvm-commits]

grimar created this revision.
grimar added reviewers: rafael, davide.
grimar added subscribers: llvm-commits, grimar, evgeny777.

It is related with PR30540, previously if sh_offset was incorrect (too large), 
returned pointer could be wrong.

It is not possible to craft file with incorrect sh_offset using yaml2obj it seems,
so used precompiled one.

https://reviews.llvm.org/D25015

Files:
  include/llvm/Object/ELF.h
  test/Object/Inputs/invalid-sh_offset.elf
  test/Object/invalid.test

Index: test/Object/invalid.test
===================================================================
--- test/Object/invalid.test
+++ test/Object/invalid.test
@@ -37,6 +37,9 @@
 RUN: not llvm-readobj -t %p/Inputs/invalid-sh_entsize.elf 2>&1 | FileCheck --check-prefix=INVALID-SYM-SIZE %s
 INVALID-SYM-SIZE: Invalid symbol size
 
+RUN: not llvm-readobj -t %p/Inputs/invalid-sh_offset.elf 2>&1 | FileCheck --check-prefix=INVALID-SYM-OFFSET %s
+INVALID-SYM-OFFSET: Invalid symbol offset
+
 RUN: not llvm-readobj --dyn-symbols %p/Inputs/invalid-sh_entsize.elf 2>&1 | FileCheck --check-prefix=INVALID-DYNSYM-SIZE %s
 INVALID-DYNSYM-SIZE: Invalid entity size
 
Index: test/Object/Inputs/invalid-sh_offset.elf
===================================================================
--- test/Object/Inputs/invalid-sh_offset.elf
+++ test/Object/Inputs/invalid-sh_offset.elf
@@ -0,0 +1 @@
+ELF

         
 > 
                               @     @  
                                                        .text foo .eh_frame .strtab .symtab                                                                                          x       %               
               
   
                  @                                         
  p               @                      
                                     H €     0       
                    
\ No newline at end of file
Index: include/llvm/Object/ELF.h
===================================================================
--- include/llvm/Object/ELF.h
+++ include/llvm/Object/ELF.h
@@ -120,6 +120,8 @@
       return nullptr;
     if (Sec->sh_entsize != sizeof(Elf_Sym))
       report_fatal_error("Invalid symbol size");
+    if (Sec->sh_offset >= Buf.size())
+      report_fatal_error("Invalid symbol offset");
     return reinterpret_cast<const Elf_Sym *>(base() + Sec->sh_offset);
   }
   const Elf_Sym *symbol_end(const Elf_Shdr *Sec) const {


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