mirror/tesseract
1
0
Fork 0
mirror of https://github.com/tesseract-ocr/tesseract.git synced 2024-12-13 07:59:04 +08:00
Code Issues Actions 10 Packages Projects Releases Wiki Activity

TFile: Improve handling of potential integer overflow

Browse Source 
Raise an assertion for unexpected arguments and use size_t instead of int
for the size argument which is typically sizeof(some_datatype).

Signed-off-by: Stefan Weil <sw@weilnetz.de>
This commit is contained in:
Stefan Weil 2018-06-04 13:52:38 +02:00
parent 45b11cd93f
commit 8bea6bcc12
2 changed files with 22 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
src/ccutil/serialis.cpp
View File

@ -98,7 +98,7 @@ char* TFile::FGets(char* buffer, int buffer_size) {
return size > 0 ? buffer : nullptr;
}
int TFile::FReadEndian(void* buffer, int size, int count) {
int TFile::FReadEndian(void* buffer, size_t size, int count) {
int num_read = FRead(buffer, size, count);
if (swap_) {
char* char_buffer = static_cast<char*>(buffer);
@ -109,12 +109,20 @@ int TFile::FReadEndian(void* buffer, int size, int count) {
return num_read;
}
int TFile::FRead(void* buffer, int size, int count) {
int TFile::FRead(void* buffer, size_t size, int count) {
ASSERT_HOST(!is_writing_);
int required_size = size * count;
if (required_size <= 0) return 0;
if (data_->size() - offset_ < required_size)
ASSERT_HOST(size > 0);
ASSERT_HOST(count > 0);
size_t required_size;
if (SIZE_MAX / size <= count) {
// Avoid integer overflow.
required_size = data_->size() - offset_;
} else {
required_size = size * count;
if (data_->size() - offset_ < required_size) {
required_size = data_->size() - offset_;
}
}
if (required_size > 0 && buffer != nullptr)
memcpy(buffer, &(*data_)[offset_], required_size);
offset_ += required_size;
@ -149,14 +157,16 @@ bool TFile::CloseWrite(const STRING& filename, FileWriter writer) {
return (*writer)(*data_, filename);
}
int TFile::FWrite(const void* buffer, int size, int count) {
int TFile::FWrite(const void* buffer, size_t size, int count) {
ASSERT_HOST(is_writing_);
int total = size * count;
if (total <= 0) return 0;
ASSERT_HOST(size > 0);
ASSERT_HOST(count > 0);
ASSERT_HOST(SIZE_MAX / size > count);
size_t total = size * count;
const char* buf = static_cast<const char*>(buffer);
// This isn't very efficient, but memory is so fast compared to disk
// that it is relatively unimportant, and very simple.
for (int i = 0; i < total; ++i)
for (size_t i = 0; i < total; ++i)
data_->push_back(buf[i]);
return count;
}

6
src/ccutil/serialis.h
View File

@ -72,9 +72,9 @@ class TFile {
// Replicates fread, followed by a swap of the bytes if needed, returning the
// number of items read. If swap_ is true then the count items will each have
// size bytes reversed.
int FReadEndian(void* buffer, int size, int count);
int FReadEndian(void* buffer, size_t size, int count);
// Replicates fread, returning the number of items read.
int FRead(void* buffer, int size, int count);
int FRead(void* buffer, size_t size, int count);
// Resets the TFile as if it has been Opened, but nothing read.
// Only allowed while reading!
void Rewind();
@ -87,7 +87,7 @@ class TFile {
// Replicates fwrite, returning the number of items written.
// To use fprintf, use snprintf and FWrite.
int FWrite(const void* buffer, int size, int count);
int FWrite(const void* buffer, size_t size, int count);
private:
// The number of bytes used so far.