PR binutils/4110

* elf.c (IS_VALID_GROUP_SECTION_HEADER): New macro.
  (setup_group): Use it.  Report corrupt group section headers.
  (bfd_section_from_shdr): Use new macro.  Replace constant 4 with
      GRP_ENTRY_SIZE.  Cope with NULLs in the group section table.
  (elf_fake_section): Replace constant 4 with GRP_ENTRY_SIZE.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 1f431a7..948b4e3 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2007-03-29  Nick Clifton  <nickc@redhat.com>
+
+       PR binutils/4110
+       * elf.c (IS_VALID_GROUP_SECTION_HEADER): New macro.
+       (setup_group): Use it.  Report corrupt group section headers.
+       (bfd_section_from_shdr): Use new macro.  Replace constant 4 with
+       GRP_ENTRY_SIZE.  Cope with NULLs in the group section table.
+       (elf_fake_section): Replace constant 4 with GRP_ENTRY_SIZE.
+
 2007-03-29  Alan Modra  <amodra@bigpond.net.au>
 
        PR ld/4267

diff --git a/bfd/elf.c b/bfd/elf.c
index 3777838..8007302 100644 (file)
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -501,10 +501,18 @@ setup_group (bfd *abfd, Elf_Internal_Shdr *hdr, asection *newsect)
         section with just a flag word (ie. sh_size is 4), ignore it.  */
       shnum = elf_numsections (abfd);
       num_group = 0;
+      
+#define IS_VALID_GROUP_SECTION_HEADER(shdr)            \
+       (   (shdr)->sh_type == SHT_GROUP                \
+        && (shdr)->sh_size >= (2 * GRP_ENTRY_SIZE)     \
+        && (shdr)->sh_entsize == GRP_ENTRY_SIZE        \
+        && ((shdr)->sh_size % GRP_ENTRY_SIZE) == 0)
+       
       for (i = 0; i < shnum; i++)
        {
          Elf_Internal_Shdr *shdr = elf_elfsections (abfd)[i];
-         if (shdr->sh_type == SHT_GROUP && shdr->sh_size >= 8)
+
+         if (IS_VALID_GROUP_SECTION_HEADER (shdr))
            num_group += 1;
        }
 
@@ -529,7 +537,8 @@ setup_group (bfd *abfd, Elf_Internal_Shdr *hdr, asection *newsect)
          for (i = 0; i < shnum; i++)
            {
              Elf_Internal_Shdr *shdr = elf_elfsections (abfd)[i];
-             if (shdr->sh_type == SHT_GROUP && shdr->sh_size >= 8)
+
+             if (IS_VALID_GROUP_SECTION_HEADER (shdr))
                {
                  unsigned char *src;
                  Elf_Internal_Group *dest;
@@ -543,8 +552,18 @@ setup_group (bfd *abfd, Elf_Internal_Shdr *hdr, asection *newsect)
                  amt = shdr->sh_size * sizeof (*dest) / 4;
                  shdr->contents = bfd_alloc2 (abfd, shdr->sh_size,
                                               sizeof (*dest) / 4);
-                 if (shdr->contents == NULL
-                     || bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0
+                 /* PR binutils/4110: Handle corrupt group headers.  */
+                 if (shdr->contents == NULL)
+                   {
+                     _bfd_error_handler
+                       (_("%B: Corrupt size field in group section header: 0x%lx"), abfd, shdr->sh_size);
+                     bfd_set_error (bfd_error_bad_value);
+                     return FALSE;
+                   }
+
+                 memset (shdr->contents, 0, amt);
+
+                 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0
                      || (bfd_bread (shdr->contents, shdr->sh_size, abfd)
                          != shdr->sh_size))
                    return FALSE;
@@ -2136,7 +2155,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
       /* We need a BFD section for objcopy and relocatable linking,
         and it's handy to have the signature available as the section
         name.  */
-      if (hdr->sh_entsize != GRP_ENTRY_SIZE)
+      if (! IS_VALID_GROUP_SECTION_HEADER (hdr))
        return FALSE;
       name = group_signature (abfd, hdr);
       if (name == NULL)
@@ -2146,7 +2165,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
       if (hdr->contents != NULL)
        {
          Elf_Internal_Group *idx = (Elf_Internal_Group *) hdr->contents;
-         unsigned int n_elt = hdr->sh_size / 4;
+         unsigned int n_elt = hdr->sh_size / GRP_ENTRY_SIZE;
          asection *s;
 
          if (idx->flags & GRP_COMDAT)
@@ -2156,12 +2175,17 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
          /* We try to keep the same section order as it comes in.  */
          idx += n_elt;
          while (--n_elt != 0)
-           if ((s = (--idx)->shdr->bfd_section) != NULL
-               && elf_next_in_group (s) != NULL)
-             {
-               elf_next_in_group (hdr->bfd_section) = s;
-               break;
-             }
+           {
+             --idx;
+
+             if (idx->shdr != NULL
+                 && (s = idx->shdr->bfd_section) != NULL
+                 && elf_next_in_group (s) != NULL)
+               {
+                 elf_next_in_group (hdr->bfd_section) = s;
+                 break;
+               }
+           }
        }
       break;
 
@@ -2830,7 +2854,7 @@ elf_fake_sections (bfd *abfd, asection *asect, void *failedptrarg)
       break;
 
     case SHT_GROUP:
-      this_hdr->sh_entsize = 4;
+      this_hdr->sh_entsize = GRP_ENTRY_SIZE;
       break;
 
     case SHT_GNU_HASH: