PR binutils/11889

        * readelf.c (get_32bit_elf_symbols): Check for a corrupt
        sh_entsize.
        (get_64bit_elf_symbols): Likewise.
        (process_symbol_table): Likewise.
        (process_section_groups): Check for corrupt headers.
        (process_version_sections): Check for corrupt indicies.
        (process_corefile_note_segment): Likewise.

1 files changed, 119 insertions, 31 deletions

diff --git a/binutils/readelf.c b/binutils/readelf.c
index 4c40e6e..2e5ca23 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -1266,7 +1266,7 @@ dump_relocations (FILE * file,
 	case EM_CR16_OLD:
 	  rtype = elf_cr16_reloc_type (type);
 	  break;
-	
+
 	case EM_MICROBLAZE:
 	case EM_MICROBLAZE_OLD:
 	  rtype = elf_microblaze_reloc_type (type);
@@ -2621,7 +2621,7 @@ get_machine_flags (unsigned e_flags, unsigned e_machine)
 	  if (e_flags & E_FLAG_RX_64BIT_DOUBLES)
 	    strcat (buf, ", 64-bit doubles");
 	  if (e_flags & E_FLAG_RX_DSP)
-	    strcat (buf, ", dsp");	  
+	    strcat (buf, ", dsp");
 
 	case EM_S390:
 	  if (e_flags & EF_S390_HIGH_GPRS)
@@ -4046,15 +4046,30 @@ static Elf_Internal_Sym *
 get_32bit_elf_symbols (FILE * file, Elf_Internal_Shdr * section)
 {
   unsigned long number;
-  Elf32_External_Sym * esyms;
+  Elf32_External_Sym * esyms = NULL;
   Elf_External_Sym_Shndx * shndx;
-  Elf_Internal_Sym * isyms;
+  Elf_Internal_Sym * isyms = NULL;
   Elf_Internal_Sym * psym;
   unsigned int j;
 
+  /* Run some sanity checks first.  */
+  if (section->sh_entsize == 0)
+    {
+      error (_("sh_entsize is zero\n"));
+      return NULL;
+    }
+
+  number = section->sh_size / section->sh_entsize;
+
+  if (number * sizeof (Elf32_External_Sym) > section->sh_size + 1)
+    {
+      error (_("Invalid sh_entsize\n"));
+      return NULL;
+    }
+
   esyms = (Elf32_External_Sym *) get_data (NULL, file, section->sh_offset, 1,
                                            section->sh_size, _("symbols"));
-  if (!esyms)
+  if (esyms == NULL)
     return NULL;
 
   shndx = NULL;
@@ -4066,28 +4081,19 @@ get_32bit_elf_symbols (FILE * file, Elf_Internal_Shdr * section)
                                                    symtab_shndx_hdr->sh_offset,
                                                    1, symtab_shndx_hdr->sh_size,
                                                    _("symtab shndx"));
-      if (!shndx)
-	{
-	  free (esyms);
-	  return NULL;
-	}
+      if (shndx == NULL)
+	goto exit_point;
     }
 
-  number = section->sh_size / section->sh_entsize;
   isyms = (Elf_Internal_Sym *) cmalloc (number, sizeof (Elf_Internal_Sym));
 
   if (isyms == NULL)
     {
       error (_("Out of memory\n"));
-      if (shndx)
-	free (shndx);
-      free (esyms);
-      return NULL;
+      goto exit_point;
     }
 
-  for (j = 0, psym = isyms;
-       j < number;
-       j++, psym++)
+  for (j = 0, psym = isyms; j < number; j++, psym++)
     {
       psym->st_name  = BYTE_GET (esyms[j].st_name);
       psym->st_value = BYTE_GET (esyms[j].st_value);
@@ -4102,9 +4108,11 @@ get_32bit_elf_symbols (FILE * file, Elf_Internal_Shdr * section)
       psym->st_other = BYTE_GET (esyms[j].st_other);
     }
 
+ exit_point:
   if (shndx)
     free (shndx);
-  free (esyms);
+  if (esyms)
+    free (esyms);
 
   return isyms;
 }
@@ -4119,6 +4127,21 @@ get_64bit_elf_symbols (FILE * file, Elf_Internal_Shdr * section)
   Elf_Internal_Sym * psym;
   unsigned int j;
 
+  /* Run some sanity checks first.  */
+  if (section->sh_entsize == 0)
+    {
+      error (_("sh_entsize is zero\n"));
+      return NULL;
+    }
+
+  number = section->sh_size / section->sh_entsize;
+
+  if (number * sizeof (Elf64_External_Sym) > section->sh_size + 1)
+    {
+      error (_("Invalid sh_entsize\n"));
+      return NULL;
+    }
+
   esyms = (Elf64_External_Sym *) get_data (NULL, file, section->sh_offset, 1,
                                            section->sh_size, _("symbols"));
   if (!esyms)
@@ -4140,7 +4163,6 @@ get_64bit_elf_symbols (FILE * file, Elf_Internal_Shdr * section)
 	}
     }
 
-  number = section->sh_size / section->sh_entsize;
   isyms = (Elf_Internal_Sym *) cmalloc (number, sizeof (Elf_Internal_Sym));
 
   if (isyms == NULL)
@@ -4965,6 +4987,12 @@ process_section_groups (FILE * file)
 	      symtab = GET_ELF_SYMBOLS (file, symtab_sec);
 	    }
 
+	  if (symtab == NULL)
+	    {
+	      error (_("Corrupt header in group section `%s'\n"), name);
+	      continue;
+	    }
+
 	  sym = symtab + section->sh_info;
 
 	  if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
@@ -6440,7 +6468,6 @@ decode_arm_unwind (struct arm_unw_aux_info *aux,
     }
   else
     {
-      
       per_index = (word >> 24) & 0x7f;
       if (per_index != 0 && per_index != 1 && per_index != 2)
 	{
@@ -7773,6 +7800,10 @@ process_version_sections (FILE * file)
 		int j;
 		int isum;
 
+		/* Check for negative or very large indicies.  */
+		if ((unsigned char *) edefs + idx < (unsigned char *) edefs)
+		  break;
+
 		vstart = ((char *) edefs) + idx;
 		if (vstart + sizeof (*edef) > endbuf)
 		  break;
@@ -7793,6 +7824,11 @@ process_version_sections (FILE * file)
 		printf (_("  Index: %d  Cnt: %d  "),
 			ent.vd_ndx, ent.vd_cnt);
 
+		/* Check for overflow.  */
+		if ((unsigned char *)(vstart + ent.vd_aux) < (unsigned char *) vstart
+		    || (unsigned char *)(vstart + ent.vd_aux) > (unsigned char *) endbuf)
+		  break;
+
 		vstart += ent.vd_aux;
 
 		eaux = (Elf_External_Verdaux *) vstart;
@@ -7809,6 +7845,11 @@ process_version_sections (FILE * file)
 
 		for (j = 1; j < ent.vd_cnt; j++)
 		  {
+		    /* Check for overflow.  */
+		    if ((unsigned char *)(vstart + aux.vda_next) < (unsigned char *) vstart
+			|| (unsigned char *)(vstart + aux.vda_next) > (unsigned char *) endbuf)
+		      break;
+
 		    isum   += aux.vda_next;
 		    vstart += aux.vda_next;
 
@@ -7826,11 +7867,13 @@ process_version_sections (FILE * file)
 		      printf (_("  %#06x: Parent %d, name index: %ld\n"),
 			      isum, j, aux.vda_name);
 		  }
+
 		if (j < ent.vd_cnt)
 		  printf (_("  Version def aux past end of section\n"));
 
 		idx += ent.vd_next;
 	      }
+
 	    if (cnt < section->sh_info)
 	      printf (_("  Version definition past end of section\n"));
 
@@ -7874,6 +7917,9 @@ process_version_sections (FILE * file)
 		int isum;
 		char * vstart;
 
+		if ((unsigned char *) eneed + idx < (unsigned char *) eneed)
+		  break;
+
 		vstart = ((char *) eneed) + idx;
 		if (vstart + sizeof (*entry) > endbuf)
 		  break;
@@ -7895,6 +7941,11 @@ process_version_sections (FILE * file)
 
 		printf (_("  Cnt: %d\n"), ent.vn_cnt);
 
+		/* Check for overflow.  */
+		if ((unsigned char *)(vstart + ent.vn_aux) < (unsigned char *) vstart
+		    || (unsigned char *)(vstart + ent.vn_aux) > (unsigned char *) endbuf)
+		  break;
+
 		vstart += ent.vn_aux;
 
 		for (j = 0, isum = idx + ent.vn_aux; j < ent.vn_cnt; ++j)
@@ -7922,6 +7973,11 @@ process_version_sections (FILE * file)
 		    printf (_("  Flags: %s  Version: %d\n"),
 			    get_ver_flags (aux.vna_flags), aux.vna_other);
 
+		    /* Check for overflow.  */
+		    if ((unsigned char *)(vstart + aux.vna_next) < (unsigned char *) vstart
+			|| (unsigned char *)(vstart + aux.vna_next) > (unsigned char *) endbuf)
+		      break;
+
 		    isum   += aux.vna_next;
 		    vstart += aux.vna_next;
 		  }
@@ -7961,6 +8017,8 @@ process_version_sections (FILE * file)
 	    found = 1;
 
 	    symbols = GET_ELF_SYMBOLS (file, link_section);
+	    if (symbols == NULL)
+	      break;
 
 	    string_sec = section_headers + link_section->sh_link;
 
@@ -8022,6 +8080,16 @@ process_version_sections (FILE * file)
 		      nn = printf ("%4x%c", data[cnt + j] & VERSYM_VERSION,
 				   data[cnt + j] & VERSYM_HIDDEN ? 'h' : ' ');
 
+		      /* If this index value is greater than the size of the symbols
+		         array, break to avoid an out-of-bounds read,  */
+		      if ((unsigned long)(cnt + j) >=
+		         ((unsigned long)link_section->sh_size /
+			  (unsigned long)link_section->sh_entsize))
+		        {
+		          warn (_("invalid index into symbol array\n"));
+		          break;
+			}
+
 		      check_def = 1;
 		      check_need = 1;
 		      if (symbols[cnt + j].st_shndx >= elf_header.e_shnum
@@ -8729,9 +8797,17 @@ process_symbol_table (FILE * file)
 		  && section->sh_type == SHT_SYMTAB))
 	    continue;
 
+	  if (section->sh_entsize == 0)
+	    {
+	      printf (_("\nSymbol table '%s' has a sh_entsize of zero!\n"),
+		      SECTION_NAME (section));
+	      continue;
+	    }
+
 	  printf (_("\nSymbol table '%s' contains %lu entries:\n"),
 		  SECTION_NAME (section),
 		  (unsigned long) (section->sh_size / section->sh_entsize));
+
 	  if (is_32bit_elf)
 	    printf (_("   Num:    Value  Size Type    Bind   Vis      Ndx Name\n"));
 	  else
@@ -9733,7 +9809,7 @@ get_section_contents (Elf_Internal_Shdr * section, FILE * file)
                              _("section contents"));
 }
 
-		      
+
 static void
 dump_section_as_strings (Elf_Internal_Shdr * section, FILE * file)
 {
@@ -10206,7 +10282,7 @@ static const char * arm_attr_tag_THUMB_ISA_use[] =
 static const char * arm_attr_tag_FP_arch[] =
   {"No", "VFPv1", "VFPv2", "VFPv3", "VFPv3-D16", "VFPv4", "VFPv4-D16"};
 static const char * arm_attr_tag_WMMX_arch[] = {"No", "WMMXv1", "WMMXv2"};
-static const char * arm_attr_tag_Advanced_SIMD_arch[] = 
+static const char * arm_attr_tag_Advanced_SIMD_arch[] =
   {"No", "NEONv1", "NEONv1 with Fused-MAC"};
 static const char * arm_attr_tag_PCS_config[] =
   {"None", "Bare platform", "Linux application", "Linux DSO", "PalmOS 2004",
@@ -10247,16 +10323,16 @@ static const char * arm_attr_tag_FP_HP_extension[] =
   {"Not Allowed", "Allowed"};
 static const char * arm_attr_tag_ABI_FP_16bit_format[] =
   {"None", "IEEE 754", "Alternative Format"};
-static const char * arm_attr_tag_MPextension_use[] = 
+static const char * arm_attr_tag_MPextension_use[] =
   {"Not Allowed", "Allowed"};
 static const char * arm_attr_tag_DIV_use[] =
-  {"Allowed in Thumb-ISA, v7-R or v7-M", "Not allowed", 
+  {"Allowed in Thumb-ISA, v7-R or v7-M", "Not allowed",
     "Allowed in v7-A with integer division extension"};
 static const char * arm_attr_tag_T2EE_use[] = {"Not Allowed", "Allowed"};
 static const char * arm_attr_tag_Virtualization_use[] =
-  {"Not Allowed", "TrustZone", "Virtualization Extensions", 
+  {"Not Allowed", "TrustZone", "Virtualization Extensions",
     "TrustZone and Virtualization Extensions"};
-static const char * arm_attr_tag_MPextension_use_legacy[] = 
+static const char * arm_attr_tag_MPextension_use_legacy[] =
   {"Not Allowed", "Allowed"};
 
 #define LOOKUP(id, name) \
@@ -10361,7 +10437,7 @@ display_arm_attribute (unsigned char * p)
 		case 3: printf ("??? 3\n"); break;
 		default:
 		  if (val <= 12)
-		    printf (_("8-byte and up to %d-byte extended\n"), 
+		    printf (_("8-byte and up to %d-byte extended\n"),
 			    1 << val);
 		  else
 		    printf ("??? (%d)\n", val);
@@ -10380,7 +10456,7 @@ display_arm_attribute (unsigned char * p)
 		case 3: printf ("??? 3\n"); break;
 		default:
 		  if (val <= 12)
-		    printf (_("8-byte and up to %d-byte extended\n"), 
+		    printf (_("8-byte and up to %d-byte extended\n"),
 			    1 << val);
 		  else
 		    printf ("??? (%d)\n", val);
@@ -11825,7 +11901,7 @@ process_corefile_note_segment (FILE * file, bfd_vma offset, bfd_vma length)
 
   pnotes = (Elf_External_Note *) get_data (NULL, file, offset, 1, length,
                                            _("notes"));
-  if (!pnotes)
+  if (pnotes == NULL)
     return 0;
 
   external = pnotes;
@@ -11849,7 +11925,8 @@ process_corefile_note_segment (FILE * file, bfd_vma offset, bfd_vma length)
 
       next = (Elf_External_Note *) (inote.descdata + align_power (inote.descsz, 2));
 
-      if (((char *) next) > (((char *) pnotes) + length))
+      if (   ((char *) next > ((char *) pnotes) + length)
+	  || ((char *) next <  (char *) pnotes))
 	{
 	  warn (_("corrupt note found at offset %lx into core notes\n"),
 		(unsigned long) ((char *) external - (char *) pnotes));
@@ -11860,6 +11937,17 @@ process_corefile_note_segment (FILE * file, bfd_vma offset, bfd_vma length)
 
       external = next;
 
+      /* Prevent out-of-bounds indexing.  */
+      if (inote.namedata + inote.namesz >= (char *) pnotes + length
+	  || inote.namedata + inote.namesz < inote.namedata)
+        {
+          warn (_("corrupt note found at offset %lx into core notes\n"),
+                (unsigned long) ((char *) external - (char *) pnotes));
+          warn (_(" type: %lx, namesize: %08lx, descsize: %08lx\n"),
+                inote.type, inote.namesz, inote.descsz);
+          break;
+        }
+
       /* Verify that name is null terminated.  It appears that at least
 	 one version of Linux (RedHat 6.0) generates corefiles that don't
 	 comply with the ELF spec by failing to include the null byte in