Test SEC_HAS_CONTENTS before reading section contents

bfd_malloc_and_get_section does size sanity checking before allocating
memory and reading contents.  These size checks are not done for bss
style sections, because they typically don't occupy file space and
thus can't be compared against file size.  However, if you are
expecting to look at something other than a whole lot of zeros, don't
allow fuzzers to avoid the size checking.

	* cofflink.c (process_embedded_commands): Don't look at
	sections without SEC_HAS_CONTENTS set.
	* cpu-arm.c (bfd_arm_update_notes): Likewise.
	(bfd_arm_get_mach_from_notes): Likewise.
	* elf-eh-frame.c (_bfd_elf_parse_eh_frame): Likewise.
	* elf-hppa.h (elf_hppa_sort_unwind): Likewise.
	* elf-m10300.c (mn10300_elf_relax_section): Likewise.
	* elf-sframe.c (_bfd_elf_parse_sframe): Likewise.
	* elf.c (_bfd_elf_print_private_bfd_data): Likewise.
	* elf32-arm.c (bfd_elf32_arm_process_before_allocation): Likewise.
	* elf32-avr.c (avr_elf32_load_property_records): Likewise.
	* elf32-ppc.c (_bfd_elf_ppc_set_arch): Likewise.
	(ppc_elf_get_synthetic_symtab, ppc_elf_relax_section): Likewise.
	* elf64-ppc.c (ppc64_elf_get_synthetic_symtab): Likewise.
	(opd_entry_value, ppc64_elf_edit_opd, ppc64_elf_edit_toc): Likewise.
	* elf64-x86-64.c (elf_x86_64_get_synthetic_symtab): Likewise.
	* elflink.c (elf_link_add_object_symbols): Likewise.
	(bfd_elf_get_bfd_needed_list): Likewise.
	* elfnn-aarch64.c (get_plt_type): Likewise.
	* elfxx-mips.c (_bfd_mips_elf_get_synthetic_symtab): Likewise.
	* linker.c (_bfd_handle_already_linked): Likewise.
	* opncls.c (bfd_get_debug_link_info_1): Likewise.
	(bfd_get_alt_debug_link_info, get_build_id): Likewise.
	* peXXigen.c (pe_print_idata, pe_print_pdata): Likewise.
	(_bfd_XX_print_ce_compressed_pdata, pe_print_reloc): Likewise.
	* pei-x86_64.c (pex64_bfd_print_pdata_section): Likewise.
	* stabs.c (_bfd_link_section_stabs): Likewise.
	(_bfd_discard_section_stabs): Likewise.
	* xcofflink.c (_bfd_xcoff_get_dynamic_symtab_upper_bound): Likewise.
	(_bfd_xcoff_canonicalize_dynamic_symtab): Likewise.
	(_bfd_xcoff_get_dynamic_reloc_upper_bound): Likewise.
	(_bfd_xcoff_canonicalize_dynamic_reloc): Likewise.
	(xcoff_link_add_dynamic_symbols): Likewise.
	(xcoff_link_check_dynamic_ar_symbols): Likewise.
	(bfd_xcoff_build_dynamic_sections): Likewise.

1 files changed, 4 insertions, 1 deletions

diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 833bc74..bb77ba2 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -1087,6 +1087,7 @@ _bfd_elf_ppc_set_arch (bfd *abfd)
       s = bfd_get_section_by_name (abfd, APUINFO_SECTION_NAME);
       if (s != NULL
 	  && s->size >= 24
+	  && (s->flags & SEC_HAS_CONTENTS) != 0
 	  && bfd_malloc_and_get_section (abfd, s, &contents))
 	{
 	  unsigned int apuinfo_size = bfd_get_32 (abfd, contents + 4);
@@ -1840,7 +1841,8 @@ ppc_elf_get_synthetic_symtab (bfd *abfd, long symcount, asymbol **syms,
   /* If this object was prelinked, the prelinker stored the address
      of .glink at got[1].  If it wasn't prelinked, got[1] will be zero.  */
   dynamic = bfd_get_section_by_name (abfd, ".dynamic");
-  if (dynamic != NULL)
+  if (dynamic != NULL
+      && (dynamic->flags & SEC_HAS_CONTENTS) != 0)
     {
       bfd_byte *dynbuf, *extdyn, *extdynend;
       size_t extdynsize;
@@ -6106,6 +6108,7 @@ ppc_elf_relax_section (bfd *abfd,
   /* No need to do anything with non-alloc or non-code sections.  */
   if ((isec->flags & SEC_ALLOC) == 0
       || (isec->flags & SEC_CODE) == 0
+      || (isec->flags & SEC_HAS_CONTENTS) == 0
       || (isec->flags & SEC_LINKER_CREATED) != 0
       || isec->size < 4)
     return true;