Fix memory access violations triggered by running readelf on fuzzed binaries.

	PR binutils/17531
	* dwarf.c (process_debug_info): Add range check.
	(display_debug_pubnames_worker): Likewise.
	(display_gdb_index): Fix range check.
	(process_cu_tu_index): Add range check.
	* readelf.c (get_data): Change parameter types from size_t to
	bfd_size_type.  Add checks for loss of accuracy when casting from
	bfd_size_type to size_t.
	(get_dynamic_data): Likewise.
	(process_section_groups): Limit number of error messages.

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index 4a6de8d18b8cb25a9c994fb5d5cc167fe4f17057..4e5f4f247bd78893cabac6703e229df21a752bb4 100644 (file)
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,16 @@
+2015-02-03  Nick Clifton  <nickc@redhat.com>
+
+       PR binutils/17531
+       * dwarf.c (process_debug_info): Add range check.
+       (display_debug_pubnames_worker): Likewise.
+       (display_gdb_index): Fix range check.
+       (process_cu_tu_index): Add range check.
+       * readelf.c (get_data): Change parameter types from size_t to
+       bfd_size_type.  Add checks for loss of accuracy when casting from
+       bfd_size_type to size_t.
+       (get_dynamic_data): Likewise.
+       (process_section_groups): Limit number of error messages.
+
 2015-02-03  Nick Clifton  <nickc@redhat.com>
 
        PR binutils/17512

diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index d82c89c6bec73e28e8c66b54b7b73bfd5a69ab98..bee8b64872cb9812786fc6956e6c34655853965a 100644 (file)
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -2444,11 +2444,19 @@ process_debug_info (struct dwarf_section *section,
                  " extends beyond end of section (length = %s)\n"),
                dwarf_vmatoa ("x", cu_offset),
                dwarf_vmatoa ("x", compunit.cu_length));
+         num_units = unit;
          break;
        }
       tags = hdrptr;
       start += compunit.cu_length + initial_length_size;
 
+      if (start > end)
+       {
+         warn (_("Debug info is corrupt.  CU at %s extends beyond end of section"),
+               dwarf_vmatoa ("x", cu_offset));
+         start = end;
+       }
+
       if (compunit.cu_version != 2
          && compunit.cu_version != 3
          && compunit.cu_version != 4)
@@ -3720,7 +3728,9 @@ display_debug_pubnames_worker (struct dwarf_section *section,
       SAFE_BYTE_GET_AND_INC (names.pn_size, data, offset_size, end);
 
       /* PR 17531: file: 7615b6b2.  */
-      if ((dwarf_signed_vma) names.pn_length < 0)
+      if ((dwarf_signed_vma) names.pn_length < 0
+         /* PR 17531: file: a5dbeaa7. */
+         || start + names.pn_length + initial_length_size < start)
        {
          warn (_("Negative length for public name: 0x%lx\n"), (long) names.pn_length);
          start = end;
@@ -6691,19 +6701,19 @@ display_gdb_index (struct dwarf_section *section,
                    constant_pool + name_offset);
 
          if (constant_pool + cu_vector_offset < constant_pool
-             || constant_pool + cu_vector_offset >= section->start + section->size)
+             || constant_pool + cu_vector_offset >= section->start + section->size - 3)
            {
              printf (_("<invalid CU vector offset: %x>\n"), cu_vector_offset);
              warn (_("Corrupt CU vector offset of 0x%x found for symbol table slot %d\n"),
                    cu_vector_offset, i);
              continue;
            }
-         else
-           num_cus = byte_get_little_endian (constant_pool + cu_vector_offset, 4);
+
+         num_cus = byte_get_little_endian (constant_pool + cu_vector_offset, 4);
 
          if (num_cus * 4 < num_cus
-             || constant_pool + cu_vector_offset + 4 + num_cus * 4 >=
-             section->start + section->size)
+             || constant_pool + cu_vector_offset + 4 + num_cus * 4
+             >= section->start + section->size)
            {
              printf ("<invalid number of CUs: %d>\n", num_cus);
              warn (_("Invalid number of CUs (0x%x) for symbol table slot %d\n"),
@@ -6864,6 +6874,14 @@ process_cu_tu_index (struct dwarf_section *section, int do_display)
   pindex = phash + nslots * 8;
   ppool = pindex + nslots * 4;
 
+  /* PR 17531: file: 45d69832.  */
+  if (pindex < phash || ppool < phdr)
+    {
+      warn (_("Section %s is too small for %d slots\n"),
+           section->name, nslots);
+      return 0;
+    }
+
   if (do_display)
     {
       printf (_("Contents of the %s section:\n\n"), section->name);

diff --git a/binutils/readelf.c b/binutils/readelf.c
index e08d74e5ca2fd5d69124af56e63a1f6ccc8d7153..a0d6f327896df359fbb3bc1303472e2a31bc16a1 100644 (file)
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -324,23 +324,45 @@ static const char *get_symbol_version_string
    context.  */
 
 static void *
-get_data (void * var, FILE * file, unsigned long offset, size_t size, size_t nmemb,
-         const char * reason)
+get_data (void * var, FILE * file, unsigned long offset, bfd_size_type size,
+         bfd_size_type nmemb, const char * reason)
 {
   void * mvar;
-  size_t amt = size * nmemb;
+  bfd_size_type amt = size * nmemb;
 
   if (size == 0 || nmemb == 0)
     return NULL;
 
+  /* If the size_t type is smaller than the bfd_size_type, eg because
+     you are building a 32-bit tool on a 64-bit host, then make sure
+     that when the sizes are cast to (size_t) no information is lost.  */
+  if (sizeof (size_t) < sizeof (bfd_size_type)
+      && (   (bfd_size_type) ((size_t) size) != size
+         || (bfd_size_type) ((size_t) nmemb) != nmemb))
+    {
+      if (reason)
+       error (_("Size truncation prevents reading 0x%llx elements of size 0x%llx for %s\n"),
+              (unsigned long long) nmemb, (unsigned long long) size, reason);
+      return NULL;
+    }
+
+  /* Check for size overflow.  */
+  if (amt < nmemb)
+    {
+      if (reason)
+       error (_("Size overflow prevents reading 0x%llx elements of size 0x%llx for %s\n"),
+              (unsigned long long) nmemb, (unsigned long long) size, reason);
+      return NULL;
+    }
+
   /* Be kind to memory chekers (eg valgrind, address sanitizer) by not
      attempting to allocate memory when the read is bound to fail.  */
   if (amt > current_file_size
       || offset + archive_file_offset + amt > current_file_size)
     {
       if (reason)
-       error (_("Reading 0x%lx bytes extends past end of file for %s\n"),
-              (unsigned long) amt, reason);
+       error (_("Reading 0x%llx bytes extends past end of file for %s\n"),
+              (unsigned long long) amt, reason);
       return NULL;
     }
 
@@ -356,26 +378,26 @@ get_data (void * var, FILE * file, unsigned long offset, size_t size, size_t nme
   if (mvar == NULL)
     {
       /* Check for overflow.  */
-      if (nmemb < (~(size_t) 0 - 1) / size)
+      if (nmemb < (~(bfd_size_type) 0 - 1) / size)
        /* + 1 so that we can '\0' terminate invalid string table sections.  */
-       mvar = malloc (size * nmemb + 1);
+       mvar = malloc ((size_t) amt + 1);
 
       if (mvar == NULL)
        {
          if (reason)
-           error (_("Out of memory allocating 0x%lx bytes for %s\n"),
-                  (unsigned long)(size * nmemb), reason);
+           error (_("Out of memory allocating 0x%llx bytes for %s\n"),
+                  (unsigned long long) amt, reason);
          return NULL;
        }
 
       ((char *) mvar)[amt] = '\0';
     }
 
-  if (fread (mvar, size, nmemb, file) != nmemb)
+  if (fread (mvar, (size_t) size, (size_t) nmemb, file) != nmemb)
     {
       if (reason)
-       error (_("Unable to read in 0x%lx bytes of %s\n"),
-              (unsigned long) amt, reason);
+       error (_("Unable to read in 0x%llx bytes of %s\n"),
+              (unsigned long long) amt, reason);
       if (mvar != var)
        free (mvar);
       return NULL;
@@ -5994,8 +6016,15 @@ process_section_groups (FILE * file)
 
              if (entry >= elf_header.e_shnum)
                {
-                 error (_("section [%5u] in group section [%5u] > maximum section [%5u]\n"),
-                        entry, i, elf_header.e_shnum - 1);
+                 static unsigned num_group_errors = 0;
+
+                 if (num_group_errors ++ < 10)
+                   {
+                     error (_("section [%5u] in group section [%5u] > maximum section [%5u]\n"),
+                            entry, i, elf_header.e_shnum - 1);
+                     if (num_group_errors == 10)
+                       warn (_("Futher error messages about overlarge group section indicies suppressed\n"));
+                   }
                  continue;
                }
 
@@ -6003,9 +6032,16 @@ process_section_groups (FILE * file)
                {
                  if (entry)
                    {
-                     error (_("section [%5u] in group section [%5u] already in group section [%5u]\n"),
-                            entry, i,
-                            section_headers_groups [entry]->group_index);
+                     static unsigned num_errs = 0;
+
+                     if (num_errs ++ < 10)
+                       {
+                         error (_("section [%5u] in group section [%5u] already in group section [%5u]\n"),
+                                entry, i,
+                                section_headers_groups [entry]->group_index);
+                         if (num_errs == 10)
+                           warn (_("Further error messages about already contained group sections suppressed\n"));
+                       }
                      continue;
                    }
                  else
@@ -10051,41 +10087,52 @@ get_symbol_index_type (unsigned int type)
 }
 
 static bfd_vma *
-get_dynamic_data (FILE * file, size_t number, unsigned int ent_size)
+get_dynamic_data (FILE * file, bfd_size_type number, unsigned int ent_size)
 {
   unsigned char * e_data;
   bfd_vma * i_data;
 
+  /* If the size_t type is smaller than the bfd_size_type, eg because
+     you are building a 32-bit tool on a 64-bit host, then make sure
+     that when (number) is cast to (size_t) no information is lost.  */
+  if (sizeof (size_t) < sizeof (bfd_size_type)
+      && (bfd_size_type) ((size_t) number) != number)
+    {
+      error (_("Size truncation prevents reading %llu elements of size %u\n"),
+            (unsigned long long) number, ent_size);
+      return NULL;
+    }
+  
   /* Be kind to memory chekers (eg valgrind, address sanitizer) by not
      attempting to allocate memory when the read is bound to fail.  */
   if (ent_size * number > current_file_size)
     {
-      error (_("Invalid number of dynamic entries: %lu\n"),
-            (unsigned long) number);
+      error (_("Invalid number of dynamic entries: %llu\n"),
+            (unsigned long long) number);
       return NULL;
     }
 
-  e_data = (unsigned char *) cmalloc (number, ent_size);
+  e_data = (unsigned char *) cmalloc ((size_t) number, ent_size);
   if (e_data == NULL)
     {
-      error (_("Out of memory reading %lu dynamic entries\n"),
-            (unsigned long) number);
+      error (_("Out of memory reading %llu dynamic entries\n"),
+            (unsigned long long) number);
       return NULL;
     }
 
-  if (fread (e_data, ent_size, number, file) != number)
+  if (fread (e_data, ent_size, (size_t) number, file) != number)
     {
-      error (_("Unable to read in %lu bytes of dynamic data\n"),
-            (unsigned long) (number * ent_size));
+      error (_("Unable to read in %llu bytes of dynamic data\n"),
+            (unsigned long long) (number * ent_size));
       free (e_data);
       return NULL;
     }
 
-  i_data = (bfd_vma *) cmalloc (number, sizeof (*i_data));
+  i_data = (bfd_vma *) cmalloc ((size_t) number, sizeof (*i_data));
   if (i_data == NULL)
     {
-      error (_("Out of memory allocating space for %lu dynamic entries\n"),
-            (unsigned long) number);
+      error (_("Out of memory allocating space for %llu dynamic entries\n"),
+            (unsigned long long) number);
       free (e_data);
       return NULL;
     }
@@ -10683,7 +10730,7 @@ process_symbol_table (FILE * file)
       printf (_(" Length  Number     %% of total  Coverage\n"));
       for (hn = 0; hn < nbuckets; ++hn)
        {
-         for (si = buckets[hn]; si > 0 && si < nchains; si = chains[si])
+         for (si = buckets[hn]; si > 0 && si < nchains && si < nbuckets; si = chains[si])
            {
              ++nsyms;
              if (maxlength < ++lengths[hn])