Examples of errors detected by the V769 diagnostic

V769. The pointer in the expression equals nullptr. The resulting value is meaningless and should not be used.

GZDoom

V769 The 'pp' pointer in the 'pp += 3' expression equals nullptr. The resulting value is senseless and it should not be used. models_voxel.cpp 145


PalettedPixels FVoxelTexture::CreatePalettedPixels(int conversion, int frame)
{
  uint8_t *pp = SourceVox->Palette.Data();

  if (pp != nullptr)
  {
    ....
  }
  else
  {
    for (int i = 0; i < 256; i++, pp+=3)
    {
      bitmap[i] = (uint8_t)i;
      pe[i] = GPalette.BaseColors[i];
      pe[i].a = 255;
    }
  }
}

GTK

V769 [CWE-119, CERT-EXP08-C] The 'end' pointer in the 'end += strlen(beg)' expression equals nullptr. The resulting value is senseless and it should not be used. position.cpp 36


Offset Offset::init(const char* beg, const char* end)
{
  Offset offset(0, 0);
  if (end == 0) {
    end += strlen(beg);
  }
  offset.add(beg, end);
  return offset;
}

Most likely this is what should be written here: end = beg + strlen(beg);

Overgrowth

V769 [CERT-EXP08-C] The 'idx_buffer_offset' pointer in the 'idx_buffer_offset += pcmd->ElemCount' expression equals nullptr. The resulting value is senseless and it should not be used. imgui_impl_sdl_gl3.cpp 138


void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data)
{
  const ImDrawIdx* idx_buffer_offset = 0;
  ....
  idx_buffer_offset += pcmd->ElemCount;
  ....
}

Similar errors can be found in some other places:

V769 [CERT-EXP08-C] The 'cp' pointer in the 'cp ++' expression equals nullptr. The resulting value is senseless and it should not be used. crn_file_utils.cpp 547

DeepSpeech

V769 The 'middle_begin_' pointer in the 'middle_begin_ + (counts.size() - 2)' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. Check lines: 553, 552. search_trie.cc 553


template <class Quant, class Bhiksha> class TrieSearch {
....
private:
  ....
  Middle *middle_begin_, *middle_end_;
  ....
};

template <class Quant, class Bhiksha>
uint8_t *TrieSearch<Quant, Bhiksha>::SetupMemory(....)
{
  ....
  middle_begin_
    = static_cast<Middle*>(malloc(sizeof(Middle) * (counts.size() - 2)));
  middle_end_ = middle_begin_ + (counts.size() - 2);
  ....
}

CSV Parser

V769 The 'buffer.get()' pointer in the 'line_buffer - buffer.get()' expression equals nullptr. The resulting value is senseless and it should not be used. csv.hpp 4957


CSV_INLINE void CSVReader::read_csv(const size_t& bytes) {
  const size_t BUFFER_UPPER_LIMIT = std::min(bytes, (size_t)1000000);
  std::unique_ptr<char[]> buffer(new char[BUFFER_UPPER_LIMIT]);
  auto * HEDLEY_RESTRICT line_buffer = buffer.get();
  line_buffer[0] = '\0';
  ....
  this->feed_state->feed_buffer.push_back(
    std::make_pair<>(std::move(buffer), line_buffer - buffer.get())); // <=
  ....
}

Newton Game Dynamics

V769 The 'result' pointer in the 'result + i' expression equals nullptr. The resulting value is senseless and it should not be used. win32_monitor.c 286


GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* count)
{
  GLFWvidmode* result = NULL;
  ....
  for (i = 0;  i < *count;  i++)
    {
    if (_glfwCompareVideoModes(result + i, &mode) == 0)
      break;
    }
}

FreeRDP

V769 The 'data' pointer in the expression equals nullptr. The resulting value of arithmetic operations on this pointer is senseless and it should not be used. nsc_encode.c 124


static BOOL nsc_encode_argb_to_aycocg(NSC_CONTEXT* context,
                                      const BYTE* data,
                                      UINT32 scanline)
{
  ....
  if (!context || data || (scanline == 0))
    return FALSE;
  ....
  src = data + (context->height - 1 - y) * scanline;
  ....
}

Qt

V769 CWE-119 The 'ptr' pointer in the expression equals nullptr. The resulting value of arithmetic operations on this pointer is senseless and it should not be used. qdbusdemarshaller.cpp 299


QVariant QDBusDemarshaller::toVariantInternal()
{
  ....
  default:
    char *ptr = 0;
    ptr += q_dbus_message_iter_get_arg_type(&iterator);
    q_dbus_message_iter_next(&iterator);

    // I hope you never dereference this pointer!
    return QVariant::fromValue<void *>(ptr);
  };
}

Android

V769 CWE-119 The '(uint32_t *) metadata' pointer in the '(uint32_t *) metadata + new_size_int' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. Check lines: 91, 89. radio_metadata.c 91


int check_size(radio_metadata_buffer_t **metadata_ptr, const uint32_t size_int)
{
  ....
  metadata = realloc(metadata,
                     new_size_int * sizeof(uint32_t));
  memmove(
   (uint32_t *)metadata + new_size_int - (metadata->count + 1),
   (uint32_t *)metadata + metadata->size_int -
                           (metadata->count + 1),
   (metadata->count + 1) * sizeof(uint32_t));
  ....
}

Hunspell

V769 CWE-119 The 'candidate' pointer in the 'candidate + 1' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. Check lines: 864, 863. suggestmgr.cxx 864


int SuggestMgr::twowords(....)
{
  ....
  char* candidate = (char*)malloc(wl + 2);
  strcpy(candidate + 1, word);
  ....
}

There is no protection if the malloc function returns a null pointer.

LLVM/Clang

V769 CWE-119 The 'NewTableArray' pointer in the 'NewTableArray + NewSize' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. Check lines: 218, 216. stringmap.cpp 218


unsigned StringMapImpl::RehashTable(unsigned BucketNo) {
  ....
  StringMapEntryBase **NewTableArray =
    (StringMapEntryBase **)calloc(NewSize+1,
      sizeof(StringMapEntryBase *) + sizeof(unsigned));
  unsigned *NewHashArray =
    (unsigned *)(NewTableArray + NewSize + 1);
  NewTableArray[NewSize] = (StringMapEntryBase*)2;
  ....
}

The bug is interesting because if calloc returns NULL, then the program will not necessarily immediately fall. A record occurs not by a null pointer, but by a shift equal to NewSize.

V8 JavaScript Engine

V769 CWE-119 The 'copy' pointer in the 'copy + prefix_len' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. Check lines: 394, 393. code-assembler.cc 394


void CodeAssembler::Comment(const char* format, ...) {
  ....
  const int prefix_len = 2;
  int length = builder.position() + 1;
  char* copy = reinterpret_cast<char*>(malloc(length +
                                              prefix_len));
  MemCopy(copy + prefix_len, builder.Finalize(), length);
  copy[0] = ';';
  copy[1] = ' ';
  raw_assembler()->Comment(copy);
}

There is no protection if the malloc function returns a null pointer.

MySQL

V769 The 'new_buffer' pointer in the 'new_buffer + fixed_header_len' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. Check lines: 74, 73. gcs_message_stage_lz4.cc 74


bool
Gcs_message_stage_lz4::apply(Gcs_packet &packet)
{
  ....
  unsigned char *new_buffer =
    (unsigned char*) malloc(new_capacity);
  unsigned char *new_payload_ptr =
    new_buffer + fixed_header_len + hd_len;

  // compress payload
  compressed_len=
    LZ4_compress_default((const char*)packet.get_payload(),
                         (char*)new_payload_ptr,
                         static_cast<int>(old_payload_len),
                         compress_bound);
  ....
}

EFL Core Libraries

V769 The 'ed->file->sound_dir->samples' pointer in the expression could be nullptr. In such case, resulting value of arithmetic operations on this pointer will be senseless and it should not be used. edje_edit.c 1271


EAPI Eina_Bool
edje_edit_sound_sample_add(Evas_Object *obj, const char *name,
                           const char *snd_src)
{
   ....
   ed->file->sound_dir->samples =
     realloc(ed->file->sound_dir->samples,
             sizeof(Edje_Sound_Sample) *
             ed->file->sound_dir->samples_count);

   sound_sample = ed->file->sound_dir->samples +
     ed->file->sound_dir->samples_count - 1;
   sound_sample->name = (char *)eina_stringshare_add(name);
   ....
}

Similar errors can be found in some other places:

V769 The 'new_txt' pointer in the 'new_txt + outlen' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. eina_str.c 539
V769 The 'new_txt' pointer in the 'new_txt + outlen' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. eina_str.c 611
V769 The 'tmp' pointer in the 'tmp ++' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. evas_object_textblock.c 11131
And 7 additional diagnostic messages.

Aspell

V769 The 'strchr(s, ':')' pointer in the 'strchr(s, ':') + 1' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. posib_err.cpp 52


PosibErrBase & PosibErrBase::set(....)
{
  ....
  s = strchr(s, ':') + 1;
  unsigned int ip = *s - '0' - 1;
  ....
}

Similar errors can be found in some other places:

V769 The 'begin_' pointer in the 'begin_ + old_size' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. string.cpp 36
V769 The 'w->data' pointer in the 'w->data + cc' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. typo_editdist.cpp 166
V769 The '(cur)->str' pointer in the '(cur)->str + pos' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. prezip.c 103
And 1 additional diagnostic messages.

Tor

V769 The 'strchr(cp, ':')' pointer in the 'strchr(cp, ':') + 2' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. dns.c 163


static void
evdns_log_cb(int warn, const char *msg)
{
  ....
  const char *err = strchr(cp, ':')+2;
  tor_assert(err);
  ....
}

Examples of errors detected by the V769 diagnostic

GZDoom

GTK

Overgrowth

DeepSpeech

CSV Parser

Newton Game Dynamics

FreeRDP

Qt

Android

Hunspell

LLVM/Clang

V8 JavaScript Engine

MySQL

EFL Core Libraries

Aspell

Tor

Want to try PVS‑Studio for free?

Achievements

PVS-Studio

Licensing

Company