Fix memory access problems discovered when running some binary tools on corrupt files.

	PR binutils/18758
	* elf.c (_bfd_elf_setup_sections): Add checks for corrupt section
	group information.
	* peicode.h (pe_ILF_make_a_section): Ensure alignment of the
	used_by_bfd pointer.
	(pe_ILF_build_a_bfd): Ensure alignment of vars.data pointer.

1 files changed, 32 insertions, 0 deletions

diff --git a/bfd/peicode.h b/bfd/peicode.h
index 06bcaa9..668e742 100644
--- a/bfd/peicode.h
+++ b/bfd/peicode.h
@@ -631,6 +631,20 @@ pe_ILF_make_a_section (pe_ILF_vars * vars,
   if (size & 1)
     vars->data --;
 
+# if (GCC_VERSION >= 3000)
+  /* PR 18758: See note in pe_ILF_buid_a_bfd.  We must make sure that we
+     preserve host alignment requirements.  We test 'size' rather than
+     vars.data as we cannot perform binary arithmetic on pointers.  We assume
+     that vars.data was sufficiently aligned upon entry to this function.
+     The BFD_ASSERTs in this functions will warn us if we run out of room,
+     but we should already have enough padding built in to ILF_DATA_SIZE.  */
+  {
+    unsigned int alignment = __alignof__ (struct coff_section_tdata);
+
+    if (size & (alignment - 1))
+      vars->data += alignment - (size & (alignment - 1));
+  }
+#endif
   /* Create a coff_section_tdata structure for our use.  */
   sec->used_by_bfd = (struct coff_section_tdata *) vars->data;
   vars->data += sizeof (struct coff_section_tdata);
@@ -836,6 +850,24 @@ pe_ILF_build_a_bfd (bfd *           abfd,
 
   /* The remaining space in bim->buffer is used
      by the pe_ILF_make_a_section() function.  */
+# if (GCC_VERSION >= 3000)
+  /* PR 18758: Make sure that the data area is sufficiently aligned for
+     pointers on the host.  __alignof__ is a gcc extension, hence the test
+     above.  For other compilers we will have to assume that the alignment is
+     unimportant, or else extra code can be added here and in
+     pe_ILF_make_a_section.
+
+     Note - we cannot test 'ptr' directly as it is illegal to perform binary
+     arithmetic on pointers, but we know that the strings section is the only
+     one that might end on an unaligned boundary.  */
+  {
+    unsigned int alignment = __alignof__ (char *);
+
+    if (SIZEOF_ILF_STRINGS & (alignment - 1))
+      ptr += alignment - (SIZEOF_ILF_STRINGS & (alignment - 1));
+  }
+#endif
+  
   vars.data = ptr;
   vars.abfd = abfd;
   vars.sec_index = 0;