Miscellaneous memory alloc related fixes

Some minor tidies.  Allocating memory for internal relocs and symbols
after reading external relocs is slightly better with fuzzed files.
You can at least do something about silly sizes that way.

	* aoutx.h (slurp_reloc_table): Allocate reloc_cache after
	reading external relocs.
	* ecoff.c (ecoff_slurp_reloc_table): Likewise.
	* archive.c (_bfd_write_archive_contents): Don't twiddle bfd_error
	after bfd_bread.
	* archive64.c (_bfd_archive_64_bit_slurp_armap): Remove unnecessary
	bfd_release.
	* elf32-m32c.c (m32c_offset_for_reloc): Make shndx_buf a bfd_byte*.
	(m32c_elf_relax_section): Likewise.
	* elf32-rl78.c (rl78_offset_for_reloc): Likewise.
	(rl78_elf_relax_section): Likewise.
	* elf32-rx.c (rx_offset_for_reloc): Likewise.
	(elf32_rx_relax_section): Likewise.
	* mach-o.c (bfd_mach_o_alloc_and_read): Move earlier with better
	parameter types and use..
	(bfd_mach_o_read_dylinker, bfd_mach_o_read_dylib),
	(bfd_mach_o_read_fvmlib, bfd_mach_o_read_str): ..in these functions.
	* peicode.h (pe_bfd_object_p): Don't zero the part of opthdr
	being read from file, just the extra.
	* som.c (som_slurp_symbol_table): Allocate internal symbol buffer
	after reading external syms.  Free on failure.

11 files changed, 98 insertions, 92 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index a9e3f67..85747ad 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,29 @@
 2020-02-19  Alan Modra  <amodra@gmail.com>
 
+	* aoutx.h (slurp_reloc_table): Allocate reloc_cache after
+	reading external relocs.
+	* ecoff.c (ecoff_slurp_reloc_table): Likewise.
+	* archive.c (_bfd_write_archive_contents): Don't twiddle bfd_error
+	after bfd_bread.
+	* archive64.c (_bfd_archive_64_bit_slurp_armap): Remove unnecessary
+	bfd_release.
+	* elf32-m32c.c (m32c_offset_for_reloc): Make shndx_buf a bfd_byte*.
+	(m32c_elf_relax_section): Likewise.
+	* elf32-rl78.c (rl78_offset_for_reloc): Likewise.
+	(rl78_elf_relax_section): Likewise.
+	* elf32-rx.c (rx_offset_for_reloc): Likewise.
+	(elf32_rx_relax_section): Likewise.
+	* mach-o.c (bfd_mach_o_alloc_and_read): Move earlier with better
+	parameter types and use..
+	(bfd_mach_o_read_dylinker, bfd_mach_o_read_dylib),
+	(bfd_mach_o_read_fvmlib, bfd_mach_o_read_str): ..in these functions.
+	* peicode.h (pe_bfd_object_p): Don't zero the part of opthdr
+	being read from file, just the extra.
+	* som.c (som_slurp_symbol_table): Allocate internal symbol buffer
+	after reading external syms.  Free on failure.
+
+2020-02-19  Alan Modra  <amodra@gmail.com>
+
 	* coffcode.h (buy_and_read, coff_slurp_line_table),
 	(coff_slurp_symbol_table, coff_slurp_reloc_table): Replace
 	bfd_[z][m]alloc2 calls with _bfd_mul_overflow followed by the
diff --git a/bfd/aoutx.h b/bfd/aoutx.h
index df04ab2..7cc72b4 100644
--- a/bfd/aoutx.h
+++ b/bfd/aoutx.h
@@ -2316,34 +2316,29 @@ NAME (aout, slurp_reloc_table) (bfd *abfd, sec_ptr asect, asymbol **symbols)
       return FALSE;
     }
 
-  if (reloc_size == 0)
-    return TRUE;		/* Nothing to be done.  */
-
-  if (bfd_seek (abfd, asect->rel_filepos, SEEK_SET) != 0)
-    return FALSE;
-
   each_size = obj_reloc_entry_size (abfd);
-
   count = reloc_size / each_size;
   if (count == 0)
     return TRUE;		/* Nothing to be done.  */
 
-  amt = count * sizeof (arelent);
-  reloc_cache = (arelent *) bfd_zmalloc (amt);
-  if (reloc_cache == NULL)
+  if (bfd_seek (abfd, asect->rel_filepos, SEEK_SET) != 0)
     return FALSE;
 
   relocs = bfd_malloc (reloc_size);
   if (relocs == NULL)
+    return FALSE;
+
+  if (bfd_bread (relocs, reloc_size, abfd) != reloc_size)
     {
-      free (reloc_cache);
+      free (relocs);
       return FALSE;
     }
 
-  if (bfd_bread (relocs, reloc_size, abfd) != reloc_size)
+  amt = count * sizeof (arelent);
+  reloc_cache = (arelent *) bfd_zmalloc (amt);
+  if (reloc_cache == NULL)
     {
       free (relocs);
-      free (reloc_cache);
       return FALSE;
     }
 
diff --git a/bfd/archive.c b/bfd/archive.c
index 67d1c9e..91127d7 100644
--- a/bfd/archive.c
+++ b/bfd/archive.c
@@ -2193,11 +2193,7 @@ _bfd_write_archive_contents (bfd *arch)
 	    amt = remaining;
 	  errno = 0;
 	  if (bfd_bread (buffer, amt, current) != amt)
-	    {
-	      if (bfd_get_error () != bfd_error_system_call)
-		bfd_set_error (bfd_error_file_truncated);
-	      goto input_err;
-	    }
+	    goto input_err;
 	  if (bfd_bwrite (buffer, amt, arch) != amt)
 	    return FALSE;
 	  remaining -= amt;
diff --git a/bfd/archive64.c b/bfd/archive64.c
index 59e42c6..c693ff9 100644
--- a/bfd/archive64.c
+++ b/bfd/archive64.c
@@ -117,7 +117,7 @@ _bfd_archive_64_bit_slurp_armap (bfd *abfd)
     {
       if (bfd_get_error () != bfd_error_system_call)
 	bfd_set_error (bfd_error_malformed_archive);
-      goto release_raw_armap;
+      goto release_symdefs;
     }
 
   stringend = stringbase + stringsize;
@@ -142,8 +142,6 @@ _bfd_archive_64_bit_slurp_armap (bfd *abfd)
 
   return TRUE;
 
-release_raw_armap:
-  bfd_release (abfd, raw_armap);
 release_symdefs:
   bfd_release (abfd, ardata->symdefs);
   return FALSE;
diff --git a/bfd/ecoff.c b/bfd/ecoff.c
index 15c18ac..1d9e385 100644
--- a/bfd/ecoff.c
+++ b/bfd/ecoff.c
@@ -1623,20 +1623,25 @@ ecoff_slurp_reloc_table (bfd *abfd,
   if (! _bfd_ecoff_slurp_symbol_table (abfd))
     return FALSE;
 
-  amt = section->reloc_count;
-  amt *= sizeof (arelent);
-  internal_relocs = (arelent *) bfd_alloc (abfd, amt);
-
   external_reloc_size = backend->external_reloc_size;
   amt = external_reloc_size * section->reloc_count;
   external_relocs = (char *) bfd_alloc (abfd, amt);
-  if (internal_relocs == NULL || external_relocs == NULL)
+  if (external_relocs == NULL)
     return FALSE;
   if (bfd_seek (abfd, section->rel_filepos, SEEK_SET) != 0)
     return FALSE;
   if (bfd_bread (external_relocs, amt, abfd) != amt)
     return FALSE;
 
+  amt = section->reloc_count;
+  amt *= sizeof (arelent);
+  internal_relocs = (arelent *) bfd_alloc (abfd, amt);
+  if (internal_relocs == NULL)
+    {
+      bfd_release (abfd, external_relocs);
+      return FALSE;
+    }
+
   for (i = 0, rptr = internal_relocs; i < section->reloc_count; i++, rptr++)
     {
       struct internal_reloc intern;
diff --git a/bfd/elf32-m32c.c b/bfd/elf32-m32c.c
index 89bdcca..a4dfd8d 100644
--- a/bfd/elf32-m32c.c
+++ b/bfd/elf32-m32c.c
@@ -1284,7 +1284,7 @@ static bfd_vma
 m32c_offset_for_reloc (bfd *abfd,
 		       Elf_Internal_Rela *rel,
 		       Elf_Internal_Shdr *symtab_hdr,
-		       Elf_External_Sym_Shndx *shndx_buf ATTRIBUTE_UNUSED,
+		       bfd_byte *shndx_buf ATTRIBUTE_UNUSED,
 		       Elf_Internal_Sym *intsyms)
 {
   bfd_vma symval;
@@ -1442,7 +1442,7 @@ m32c_elf_relax_section
   bfd_byte * free_contents = NULL;
   Elf_Internal_Sym *intsyms = NULL;
   Elf_Internal_Sym *free_intsyms = NULL;
-  Elf_External_Sym_Shndx *shndx_buf = NULL;
+  bfd_byte *shndx_buf = NULL;
   int machine;
 
   if (abfd == elf_hash_table (link_info)->dynobj
@@ -1499,13 +1499,13 @@ m32c_elf_relax_section
 	  bfd_set_error (bfd_error_file_too_big);
 	  goto error_return;
 	}
-      shndx_buf = (Elf_External_Sym_Shndx *) bfd_malloc (amt);
+      shndx_buf = bfd_malloc (amt);
       if (shndx_buf == NULL)
 	goto error_return;
       if (bfd_seek (abfd, shndx_hdr->sh_offset, SEEK_SET) != 0
 	  || bfd_bread (shndx_buf, amt, abfd) != amt)
 	goto error_return;
-      shndx_hdr->contents = (bfd_byte *) shndx_buf;
+      shndx_hdr->contents = shndx_buf;
     }
 
   /* Get a copy of the native relocations.  */
diff --git a/bfd/elf32-rl78.c b/bfd/elf32-rl78.c
index f4abf04..40f8c58 100644
--- a/bfd/elf32-rl78.c
+++ b/bfd/elf32-rl78.c
@@ -1822,7 +1822,7 @@ static bfd_vma
 rl78_offset_for_reloc (bfd *			abfd,
 		       Elf_Internal_Rela *	rel,
 		       Elf_Internal_Shdr *	symtab_hdr,
-		       Elf_External_Sym_Shndx * shndx_buf ATTRIBUTE_UNUSED,
+		       bfd_byte *		shndx_buf ATTRIBUTE_UNUSED,
 		       Elf_Internal_Sym *	intsyms,
 		       Elf_Internal_Rela **	lrel,
 		       bfd *			input_bfd,
@@ -2068,7 +2068,7 @@ rl78_elf_relax_section
   bfd_byte *	      free_contents = NULL;
   Elf_Internal_Sym *  intsyms = NULL;
   Elf_Internal_Sym *  free_intsyms = NULL;
-  Elf_External_Sym_Shndx * shndx_buf = NULL;
+  bfd_byte *	      shndx_buf = NULL;
   bfd_vma pc;
   bfd_vma symval ATTRIBUTE_UNUSED = 0;
   int pcrel ATTRIBUTE_UNUSED = 0;
@@ -2129,13 +2129,13 @@ rl78_elf_relax_section
 	  bfd_set_error (bfd_error_no_memory);
 	  goto error_return;
 	}
-      shndx_buf = (Elf_External_Sym_Shndx *) bfd_malloc (amt);
+      shndx_buf = bfd_malloc (amt);
       if (shndx_buf == NULL)
 	goto error_return;
       if (bfd_seek (abfd, shndx_hdr->sh_offset, SEEK_SET) != 0
 	  || bfd_bread (shndx_buf, amt, abfd) != amt)
 	goto error_return;
-      shndx_hdr->contents = (bfd_byte *) shndx_buf;
+      shndx_hdr->contents = shndx_buf;
     }
 
   /* Get a copy of the native relocations.  */
diff --git a/bfd/elf32-rx.c b/bfd/elf32-rx.c
index a94aee7..0a9900f 100644
--- a/bfd/elf32-rx.c
+++ b/bfd/elf32-rx.c
@@ -1738,7 +1738,7 @@ static bfd_vma
 rx_offset_for_reloc (bfd *		      abfd,
 		     Elf_Internal_Rela *      rel,
 		     Elf_Internal_Shdr *      symtab_hdr,
-		     Elf_External_Sym_Shndx * shndx_buf ATTRIBUTE_UNUSED,
+		     bfd_byte *		      shndx_buf ATTRIBUTE_UNUSED,
 		     Elf_Internal_Sym *	      intsyms,
 		     Elf_Internal_Rela **     lrel,
 		     bfd *		      input_bfd,
@@ -2005,7 +2005,7 @@ elf32_rx_relax_section (bfd *		       abfd,
   bfd_byte *	      free_contents = NULL;
   Elf_Internal_Sym *  intsyms = NULL;
   Elf_Internal_Sym *  free_intsyms = NULL;
-  Elf_External_Sym_Shndx * shndx_buf = NULL;
+  bfd_byte *	      shndx_buf = NULL;
   bfd_vma pc;
   bfd_vma sec_start;
   bfd_vma symval = 0;
@@ -2066,13 +2066,13 @@ elf32_rx_relax_section (bfd *		       abfd,
 	  bfd_set_error (bfd_error_file_too_big);
 	  goto error_return;
 	}
-      shndx_buf = (Elf_External_Sym_Shndx *) bfd_malloc (amt);
+      shndx_buf = bfd_malloc (amt);
       if (shndx_buf == NULL)
 	goto error_return;
       if (bfd_seek (abfd, shndx_hdr->sh_offset, SEEK_SET) != 0
 	  || bfd_bread (shndx_buf, amt, abfd) != amt)
 	goto error_return;
-      shndx_hdr->contents = (bfd_byte *) shndx_buf;
+      shndx_hdr->contents = shndx_buf;
     }
 
   /* Get a copy of the native relocations.  */
diff --git a/bfd/mach-o.c b/bfd/mach-o.c
index 1cc9d43..fd9f480 100644
--- a/bfd/mach-o.c
+++ b/bfd/mach-o.c
@@ -3997,6 +3997,20 @@ bfd_mach_o_ppc_flavour_string (unsigned int flavour)
     }
 }
 
+static unsigned char *
+bfd_mach_o_alloc_and_read (bfd *abfd, file_ptr filepos, size_t size)
+{
+  unsigned char *buf;
+
+  buf = bfd_alloc (abfd, size);
+  if (buf == NULL)
+    return NULL;
+  if (bfd_seek (abfd, filepos, SEEK_SET) != 0
+      || bfd_bread (buf, size, abfd) != size)
+    return NULL;
+  return buf;
+}
+
 static bfd_boolean
 bfd_mach_o_read_dylinker (bfd *abfd, bfd_mach_o_load_command *command)
 {
@@ -4017,13 +4031,8 @@ bfd_mach_o_read_dylinker (bfd *abfd, bfd_mach_o_load_command *command)
   cmd->name_offset = nameoff;
   namelen = command->len - nameoff;
   nameoff += command->offset;
-  cmd->name_str = bfd_alloc (abfd, namelen);
-  if (cmd->name_str == NULL)
-    return FALSE;
-  if (bfd_seek (abfd, nameoff, SEEK_SET) != 0
-      || bfd_bread (cmd->name_str, namelen, abfd) != namelen)
-    return FALSE;
-  return TRUE;
+  cmd->name_str = (char *) bfd_mach_o_alloc_and_read (abfd, nameoff, namelen);
+  return cmd->name_str != NULL;
 }
 
 static bfd_boolean
@@ -4034,6 +4043,7 @@ bfd_mach_o_read_dylib (bfd *abfd, bfd_mach_o_load_command *command)
   struct mach_o_dylib_command_external raw;
   unsigned int nameoff;
   unsigned int namelen;
+  file_ptr pos;
 
   if (command->len < sizeof (raw) + 8)
     return FALSE;
@@ -4063,13 +4073,9 @@ bfd_mach_o_read_dylib (bfd *abfd, bfd_mach_o_load_command *command)
 
   cmd->name_offset = command->offset + nameoff;
   namelen = command->len - nameoff;
-  cmd->name_str = bfd_alloc (abfd, namelen);
-  if (cmd->name_str == NULL)
-    return FALSE;
-  if (bfd_seek (abfd, mdata->hdr_offset + cmd->name_offset, SEEK_SET) != 0
-      || bfd_bread (cmd->name_str, namelen, abfd) != namelen)
-    return FALSE;
-  return TRUE;
+  pos = mdata->hdr_offset + cmd->name_offset;
+  cmd->name_str = (char *) bfd_mach_o_alloc_and_read (abfd, pos, namelen);
+  return cmd->name_str != NULL;
 }
 
 static bfd_boolean
@@ -4163,13 +4169,9 @@ bfd_mach_o_read_fvmlib (bfd *abfd, bfd_mach_o_load_command *command)
 
   fvm->name_offset = command->offset + nameoff;
   namelen = command->len - nameoff;
-  fvm->name_str = bfd_alloc (abfd, namelen);
-  if (fvm->name_str == NULL)
-    return FALSE;
-  if (bfd_seek (abfd, fvm->name_offset, SEEK_SET) != 0
-      || bfd_bread (fvm->name_str, namelen, abfd) != namelen)
-    return FALSE;
-  return TRUE;
+  fvm->name_str = (char *) bfd_mach_o_alloc_and_read (abfd, fvm->name_offset,
+						      namelen);
+  return fvm->name_str != NULL;
 }
 
 static bfd_boolean
@@ -4568,27 +4570,9 @@ bfd_mach_o_read_str (bfd *abfd, bfd_mach_o_load_command *command)
 
   cmd->stroff = command->offset + off;
   cmd->str_len = command->len - off;
-  cmd->str = bfd_alloc (abfd, cmd->str_len);
-  if (cmd->str == NULL)
-    return FALSE;
-  if (bfd_seek (abfd, cmd->stroff, SEEK_SET) != 0
-      || bfd_bread ((void *) cmd->str, cmd->str_len, abfd) != cmd->str_len)
-    return FALSE;
-  return TRUE;
-}
-
-static unsigned char *
-bfd_mach_o_alloc_and_read (bfd *abfd, unsigned int off, unsigned int size)
-{
-  unsigned char *buf;
-
-  buf = bfd_alloc (abfd, size);
-  if (buf == NULL)
-    return NULL;
-  if (bfd_seek (abfd, off, SEEK_SET) != 0
-      || bfd_bread (buf, size, abfd) != size)
-    return NULL;
-  return buf;
+  cmd->str = (char *) bfd_mach_o_alloc_and_read (abfd, cmd->stroff,
+						 cmd->str_len);
+  return cmd->str != NULL;
 }
 
 static bfd_boolean
diff --git a/bfd/peicode.h b/bfd/peicode.h
index c1bc81b..3f772a0 100644
--- a/bfd/peicode.h
+++ b/bfd/peicode.h
@@ -1408,7 +1408,7 @@ pe_bfd_object_p (bfd * abfd)
   struct external_PEI_IMAGE_hdr image_hdr;
   struct internal_filehdr internal_f;
   struct internal_aouthdr internal_a;
-  file_ptr opt_hdr_size;
+  bfd_size_type opt_hdr_size;
   file_ptr offset;
   const bfd_target *result;
 
@@ -1494,12 +1494,14 @@ pe_bfd_object_p (bfd * abfd)
       if (amt < sizeof (PEAOUTHDR))
 	amt = sizeof (PEAOUTHDR);
 
-      opthdr = bfd_zalloc (abfd, amt);
+      opthdr = bfd_alloc (abfd, amt);
       if (opthdr == NULL)
 	return NULL;
       if (bfd_bread (opthdr, opt_hdr_size, abfd)
 	  != (bfd_size_type) opt_hdr_size)
 	return NULL;
+      if (amt > opt_hdr_size)
+	memset (opthdr + opt_hdr_size, 0, amt - opt_hdr_size);
 
       bfd_set_error (bfd_error_no_error);
       bfd_coff_swap_aouthdr_in (abfd, opthdr, & internal_a);
diff --git a/bfd/som.c b/bfd/som.c
index d7d4d8f..bd68592 100644
--- a/bfd/som.c
+++ b/bfd/som.c
@@ -4659,7 +4659,7 @@ som_slurp_symbol_table (bfd *abfd)
   size_t symsize = sizeof (struct som_external_symbol_dictionary_record);
   char *stringtab;
   struct som_external_symbol_dictionary_record *buf = NULL, *bufp, *endbufp;
-  som_symbol_type *sym, *symbase;
+  som_symbol_type *sym, *symbase = NULL;
   size_t amt;
 
   /* Return saved value if it exists.  */
@@ -4675,15 +4675,6 @@ som_slurp_symbol_table (bfd *abfd)
 
   stringtab = obj_som_stringtab (abfd);
 
-  if (_bfd_mul_overflow (symbol_count, sizeof (som_symbol_type), &amt))
-    {
-      bfd_set_error (bfd_error_file_too_big);
-      goto error_return;
-    }
-  symbase = bfd_zmalloc (amt);
-  if (symbase == NULL)
-    goto error_return;
-
   /* Read in the external SOM representation.  */
   if (_bfd_mul_overflow (symbol_count, symsize, &amt))
     {
@@ -4698,6 +4689,15 @@ som_slurp_symbol_table (bfd *abfd)
   if (bfd_bread (buf, amt, abfd) != amt)
     goto error_return;
 
+  if (_bfd_mul_overflow (symbol_count, sizeof (som_symbol_type), &amt))
+    {
+      bfd_set_error (bfd_error_file_too_big);
+      goto error_return;
+    }
+  symbase = bfd_zmalloc (amt);
+  if (symbase == NULL)
+    goto error_return;
+
   /* Iterate over all the symbols and internalize them.  */
   endbufp = buf + symbol_count;
   for (bufp = buf, sym = symbase; bufp < endbufp; ++bufp)
@@ -4837,6 +4837,8 @@ som_slurp_symbol_table (bfd *abfd)
   return (TRUE);
 
  error_return:
+  if (symbase != NULL)
+    free (symbase);
   if (buf != NULL)
     free (buf);
   return FALSE;