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.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index e1d9379..547ef1c 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,8 +1,13 @@
 2014-10-27  Nick Clifton  <nickc@redhat.com>
 
        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 (_bfd_XXi_swap_aouthdr_in): Handle corrupt binaries
        with an invalid value for NumberOfRvaAndSizes.
+       (pe_print_edata): Detect out of range rvas and entry counts for
+       the Export Address table, Name Pointer table and Ordinal table.
 
        PR binutils/17510
        * elf.c (setup_group): Improve handling of corrupt group

diff --git a/bfd/elf.c b/bfd/elf.c
index c8ac826..3fcf2d8 100644 (file)
--- 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.  */

diff --git a/bfd/peXXigen.c b/bfd/peXXigen.c
index 987be40..c7d6067 100644 (file)
--- a/bfd/peXXigen.c
+++ b/bfd/peXXigen.c
@@ -1705,7 +1705,12 @@ pe_print_edata (bfd * abfd, void * vfile)
          _("\nExport Address Table -- Ordinal Base %ld\n"),
          edt.base);
 
-  for (i = 0; i < edt.num_functions; ++i)
+  /* PR 17512: Handle corrupt PE binaries.  */
+  if (edt.eat_addr + (edt.num_functions * 4) - adj >= datasize)
+    fprintf (file, _("\tInvalid Export Address Table rva (0x%lx) or entry count (0x%lx)\n"),
+            (long) edt.eat_addr,
+            (long) edt.num_functions);
+  else for (i = 0; i < edt.num_functions; ++i)
     {
       bfd_vma eat_member = bfd_get_32 (abfd,
                                       data + edt.eat_addr + (i * 4) - adj);
@@ -1741,7 +1746,16 @@ pe_print_edata (bfd * abfd, void * vfile)
   fprintf (file,
           _("\n[Ordinal/Name Pointer] Table\n"));
 
-  for (i = 0; i < edt.num_names; ++i)
+  /* PR 17512: Handle corrupt PE binaries.  */
+  if (edt.npt_addr + (edt.num_names * 4) - adj >= datasize)
+    fprintf (file, _("\tInvalid Name Pointer Table rva (0x%lx) or entry count (0x%lx)\n"),
+            (long) edt.npt_addr,
+            (long) edt.num_names);
+  else if (edt.ot_addr + (edt.num_names * 2) - adj >= datasize)
+    fprintf (file, _("\tInvalid Ordinal Table rva (0x%lx) or entry count (0x%lx)\n"),
+            (long) edt.ot_addr,
+            (long) edt.num_names);
+  else for (i = 0; i < edt.num_names; ++i)
     {
       bfd_vma name_ptr = bfd_get_32 (abfd,
                                    data +