This fixes more seg-faults in tools like "strings" and "objdump" when

presented with corrupt binaries.

	PR binutils/17512
	* elf.c (bfd_section_from_shdr): Detect and warn about ELF
	binaries with a group of sections linked by the string table
	indicies.
	* peXXigen.c (pe_print_edata): Detect out of range rvas and
	entry counts for the Export Address table, Name Pointer table
	 and Ordinal table.

1 files changed, 129 insertions, 65 deletions

diff --git a/bfd/elf.c b/bfd/elf.c
index c8ac826..3fcf2d8 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -1578,38 +1578,67 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
   Elf_Internal_Ehdr *ehdr;
   const struct elf_backend_data *bed;
   const char *name;
+  bfd_boolean ret = TRUE;
+  static bfd_boolean * sections_being_created = NULL;
+  static unsigned int nesting = 0;
 
   if (shindex >= elf_numsections (abfd))
     return FALSE;
 
+  if (++ nesting > 3)
+    {
+      /* PR17512: A corrupt ELF binary might contain a recursive group of
+	 sections, each the string indicies pointing to the next in the
+	 loop.  Detect this here, by refusing to load a section that we are
+	 already in the process of loading.  We only trigger this test if
+	 we have nested at least three sections deep as normal ELF binaries
+	 can expect to recurse at least once.  */
+      
+      if (sections_being_created == NULL)
+	{
+	  /* FIXME: It would be more efficient to attach this array to the bfd somehow.  */
+	  sections_being_created = (bfd_boolean *)
+	    bfd_zalloc (abfd, elf_numsections (abfd) * sizeof (bfd_boolean));
+	}
+      if (sections_being_created [shindex])
+	{
+	  (*_bfd_error_handler)
+	    (_("%B: warning: loop in section dependencies detected"), abfd);
+	  return FALSE;
+	}
+      sections_being_created [shindex] = TRUE;
+    }
+
   hdr = elf_elfsections (abfd)[shindex];
   ehdr = elf_elfheader (abfd);
   name = bfd_elf_string_from_elf_section (abfd, ehdr->e_shstrndx,
 					  hdr->sh_name);
   if (name == NULL)
-    return FALSE;
+    goto fail;
 
   bed = get_elf_backend_data (abfd);
   switch (hdr->sh_type)
     {
     case SHT_NULL:
       /* Inactive section. Throw it away.  */
-      return TRUE;
+      goto success;
 
-    case SHT_PROGBITS:	/* Normal section with contents.  */
-    case SHT_NOBITS:	/* .bss section.  */
-    case SHT_HASH:	/* .hash section.  */
-    case SHT_NOTE:	/* .note section.  */
+    case SHT_PROGBITS:		/* Normal section with contents.  */
+    case SHT_NOBITS:		/* .bss section.  */
+    case SHT_HASH:		/* .hash section.  */
+    case SHT_NOTE:		/* .note section.  */
     case SHT_INIT_ARRAY:	/* .init_array section.  */
     case SHT_FINI_ARRAY:	/* .fini_array section.  */
     case SHT_PREINIT_ARRAY:	/* .preinit_array section.  */
     case SHT_GNU_LIBLIST:	/* .gnu.liblist section.  */
     case SHT_GNU_HASH:		/* .gnu.hash section.  */
-      return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      goto success;
 
     case SHT_DYNAMIC:	/* Dynamic linking information.  */
       if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
-	return FALSE;
+	goto fail;
+
       if (hdr->sh_link > elf_numsections (abfd))
 	{
 	  /* PR 10478: Accept Solaris binaries with a sh_link
@@ -1623,11 +1652,11 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		break;
 	      /* Otherwise fall through.  */
 	    default:
-	      return FALSE;
+	      goto fail;
 	    }
 	}
       else if (elf_elfsections (abfd)[hdr->sh_link] == NULL)
-	return FALSE;
+	goto fail;
       else if (elf_elfsections (abfd)[hdr->sh_link]->sh_type != SHT_STRTAB)
 	{
 	  Elf_Internal_Shdr *dynsymhdr;
@@ -1656,24 +1685,26 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		}
 	    }
 	}
-      break;
+      goto success;
 
-    case SHT_SYMTAB:		/* A symbol table */
+    case SHT_SYMTAB:		/* A symbol table.  */
       if (elf_onesymtab (abfd) == shindex)
-	return TRUE;
+	goto success;
 
       if (hdr->sh_entsize != bed->s->sizeof_sym)
-	return FALSE;
+	goto fail;
+
       if (hdr->sh_info * hdr->sh_entsize > hdr->sh_size)
 	{
 	  if (hdr->sh_size != 0)
-	    return FALSE;
+	    goto fail;
 	  /* Some assemblers erroneously set sh_info to one with a
 	     zero sh_size.  ld sees this as a global symbol count
 	     of (unsigned) -1.  Fix it here.  */
 	  hdr->sh_info = 0;
-	  return TRUE;
+	  goto success;
 	}
+
       BFD_ASSERT (elf_onesymtab (abfd) == 0);
       elf_onesymtab (abfd) = shindex;
       elf_tdata (abfd)->symtab_hdr = *hdr;
@@ -1690,7 +1721,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	  && (abfd->flags & DYNAMIC) != 0
 	  && ! _bfd_elf_make_section_from_shdr (abfd, hdr, name,
 						shindex))
-	return FALSE;
+	goto fail;
 
       /* Go looking for SHT_SYMTAB_SHNDX too, since if there is one we
 	 can't read symbols without that section loaded as well.  It
@@ -1716,26 +1747,29 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		  break;
 	      }
 	  if (i != shindex)
-	    return bfd_section_from_shdr (abfd, i);
+	    ret = bfd_section_from_shdr (abfd, i);
 	}
-      return TRUE;
+      goto success;
 
-    case SHT_DYNSYM:		/* A dynamic symbol table */
+    case SHT_DYNSYM:		/* A dynamic symbol table.  */
       if (elf_dynsymtab (abfd) == shindex)
-	return TRUE;
+	goto success;
 
       if (hdr->sh_entsize != bed->s->sizeof_sym)
-	return FALSE;
+	goto fail;
+
       if (hdr->sh_info * hdr->sh_entsize > hdr->sh_size)
 	{
 	  if (hdr->sh_size != 0)
-	    return FALSE;
+	    goto fail;
+
 	  /* Some linkers erroneously set sh_info to one with a
 	     zero sh_size.  ld sees this as a global symbol count
 	     of (unsigned) -1.  Fix it here.  */
 	  hdr->sh_info = 0;
-	  return TRUE;
+	  goto success;
 	}
+
       BFD_ASSERT (elf_dynsymtab (abfd) == 0);
       elf_dynsymtab (abfd) = shindex;
       elf_tdata (abfd)->dynsymtab_hdr = *hdr;
@@ -1744,34 +1778,38 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 
       /* Besides being a symbol table, we also treat this as a regular
 	 section, so that objcopy can handle it.  */
-      return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      goto success;
 
-    case SHT_SYMTAB_SHNDX:	/* Symbol section indices when >64k sections */
+    case SHT_SYMTAB_SHNDX:	/* Symbol section indices when >64k sections.  */
       if (elf_symtab_shndx (abfd) == shindex)
-	return TRUE;
+	goto success;
 
       BFD_ASSERT (elf_symtab_shndx (abfd) == 0);
       elf_symtab_shndx (abfd) = shindex;
       elf_tdata (abfd)->symtab_shndx_hdr = *hdr;
       elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->symtab_shndx_hdr;
-      return TRUE;
+      goto success;
 
-    case SHT_STRTAB:		/* A string table */
+    case SHT_STRTAB:		/* A string table.  */
       if (hdr->bfd_section != NULL)
-	return TRUE;
+	goto success;
+
       if (ehdr->e_shstrndx == shindex)
 	{
 	  elf_tdata (abfd)->shstrtab_hdr = *hdr;
 	  elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->shstrtab_hdr;
-	  return TRUE;
+	  goto success;
 	}
+
       if (elf_elfsections (abfd)[elf_onesymtab (abfd)]->sh_link == shindex)
 	{
 	symtab_strtab:
 	  elf_tdata (abfd)->strtab_hdr = *hdr;
 	  elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->strtab_hdr;
-	  return TRUE;
+	  goto success;
 	}
+
       if (elf_elfsections (abfd)[elf_dynsymtab (abfd)]->sh_link == shindex)
 	{
 	dynsymtab_strtab:
@@ -1780,8 +1818,9 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	  elf_elfsections (abfd)[shindex] = hdr;
 	  /* We also treat this as a regular section, so that objcopy
 	     can handle it.  */
-	  return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
-						  shindex);
+	  ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+						 shindex);
+	  goto success;
 	}
 
       /* If the string table isn't one of the above, then treat it as a
@@ -1799,9 +1838,9 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		{
 		  /* Prevent endless recursion on broken objects.  */
 		  if (i == shindex)
-		    return FALSE;
+		    goto fail;
 		  if (! bfd_section_from_shdr (abfd, i))
-		    return FALSE;
+		    goto fail;
 		  if (elf_onesymtab (abfd) == i)
 		    goto symtab_strtab;
 		  if (elf_dynsymtab (abfd) == i)
@@ -1809,7 +1848,8 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		}
 	    }
 	}
-      return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      goto success;
 
     case SHT_REL:
     case SHT_RELA:
@@ -1824,7 +1864,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	if (hdr->sh_entsize
 	    != (bfd_size_type) (hdr->sh_type == SHT_REL
 				? bed->s->sizeof_rel : bed->s->sizeof_rela))
-	  return FALSE;
+	  goto fail;
 
 	/* Check for a bogus link to avoid crashing.  */
 	if (hdr->sh_link >= num_sec)
@@ -1832,8 +1872,9 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	    ((*_bfd_error_handler)
 	     (_("%B: invalid link %lu for reloc section %s (index %u)"),
 	      abfd, hdr->sh_link, name, shindex));
-	    return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
-						    shindex);
+	    ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+						   shindex);
+	    goto success;
 	  }
 
 	/* For some incomprehensible reason Oracle distributes
@@ -1874,7 +1915,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	if ((elf_elfsections (abfd)[hdr->sh_link]->sh_type == SHT_SYMTAB
 	     || elf_elfsections (abfd)[hdr->sh_link]->sh_type == SHT_DYNSYM)
 	    && ! bfd_section_from_shdr (abfd, hdr->sh_link))
-	  return FALSE;
+	  goto fail;
 
 	/* If this reloc section does not use the main symbol table we
 	   don't treat it as a reloc section.  BFD can't adequately
@@ -1889,14 +1930,18 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	    || hdr->sh_info >= num_sec
 	    || elf_elfsections (abfd)[hdr->sh_info]->sh_type == SHT_REL
 	    || elf_elfsections (abfd)[hdr->sh_info]->sh_type == SHT_RELA)
-	  return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
-						  shindex);
+	  {
+	    ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+						   shindex);
+	    goto success;
+	  }
 
 	if (! bfd_section_from_shdr (abfd, hdr->sh_info))
-	  return FALSE;
+	  goto fail;
+
 	target_sect = bfd_section_from_elf_index (abfd, hdr->sh_info);
 	if (target_sect == NULL)
-	  return FALSE;
+	  goto fail;
 
 	esdt = elf_section_data (target_sect);
 	if (hdr->sh_type == SHT_RELA)
@@ -1908,7 +1953,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	amt = sizeof (*hdr2);
 	hdr2 = (Elf_Internal_Shdr *) bfd_alloc (abfd, amt);
 	if (hdr2 == NULL)
-	  return FALSE;
+	  goto fail;
 	*hdr2 = *hdr;
 	*p_hdr = hdr2;
 	elf_elfsections (abfd)[shindex] = hdr2;
@@ -1924,34 +1969,40 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	      target_sect->use_rela_p = 1;
 	  }
 	abfd->flags |= HAS_RELOC;
-	return TRUE;
+	goto success;
       }
 
     case SHT_GNU_verdef:
       elf_dynverdef (abfd) = shindex;
       elf_tdata (abfd)->dynverdef_hdr = *hdr;
-      return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      goto success;
 
     case SHT_GNU_versym:
       if (hdr->sh_entsize != sizeof (Elf_External_Versym))
-	return FALSE;
+	goto fail;
+
       elf_dynversym (abfd) = shindex;
       elf_tdata (abfd)->dynversym_hdr = *hdr;
-      return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      goto success;
 
     case SHT_GNU_verneed:
       elf_dynverref (abfd) = shindex;
       elf_tdata (abfd)->dynverref_hdr = *hdr;
-      return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+      goto success;
 
     case SHT_SHLIB:
-      return TRUE;
+      goto success;
 
     case SHT_GROUP:
       if (! IS_VALID_GROUP_SECTION_HEADER (hdr, GRP_ENTRY_SIZE))
-	return FALSE;
+	goto fail;
+
       if (!_bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
-	return FALSE;
+	goto fail;
+
       if (hdr->contents != NULL)
 	{
 	  Elf_Internal_Group *idx = (Elf_Internal_Group *) hdr->contents;
@@ -1977,7 +2028,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		}
 	    }
 	}
-      break;
+      goto success;
 
     default:
       /* Possibly an attributes section.  */
@@ -1985,14 +2036,14 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	  || hdr->sh_type == bed->obj_attrs_section_type)
 	{
 	  if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
-	    return FALSE;
+	    goto fail;
 	  _bfd_elf_parse_attributes (abfd, hdr);
-	  return TRUE;
+	  goto success;
 	}
 
       /* Check for any processor-specific section types.  */
       if (bed->elf_backend_section_from_shdr (abfd, hdr, name, shindex))
-	return TRUE;
+	goto success;
 
       if (hdr->sh_type >= SHT_LOUSER && hdr->sh_type <= SHT_HIUSER)
 	{
@@ -2004,9 +2055,12 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		 "specific section `%s' [0x%8x]"),
 	       abfd, name, hdr->sh_type);
 	  else
-	    /* Allow sections reserved for applications.  */
-	    return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
-						    shindex);
+	    {
+	      /* Allow sections reserved for applications.  */
+	      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+						     shindex);
+	      goto success;
+	    }
 	}
       else if (hdr->sh_type >= SHT_LOPROC
 	       && hdr->sh_type <= SHT_HIPROC)
@@ -2027,8 +2081,11 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 		 "`%s' [0x%8x]"),
 	       abfd, name, hdr->sh_type);
 	  else
-	    /* Otherwise it should be processed.  */
-	    return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+	    {
+	      /* Otherwise it should be processed.  */
+	      ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+	      goto success;
+	    }
 	}
       else
 	/* FIXME: We should handle this section.  */
@@ -2036,10 +2093,17 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 	  (_("%B: don't know how to handle section `%s' [0x%8x]"),
 	   abfd, name, hdr->sh_type);
 
-      return FALSE;
+      goto fail;
     }
 
-  return TRUE;
+ fail:
+  ret = FALSE;
+ success:
+  if (sections_being_created)
+    sections_being_created [shindex] = FALSE;
+  if (-- nesting == 0)
+    sections_being_created = NULL;
+  return ret;
 }
 
 /* Return the local symbol specified by ABFD, R_SYMNDX.  */