Huaisi Xu created THRIFT-3821: --------------------------------- Summary: TMemoryBuffer buffer may overflow when resizing Key: THRIFT-3821 URL: https://issues.apache.org/jira/browse/THRIFT-3821 Project: Thrift Issue Type: Bug Affects Versions: 0.9.3 Reporter: Huaisi Xu Priority: Critical
uint32_t new_size = bufferSize_; while (len > avail) { new_size = new_size > 0 ? new_size * 2 : 1; avail = available_write() + (new_size - bufferSize_); } // Allocate into a new pointer so we don't bork ours if it fails. uint8_t* new_buffer = static_cast<uint8_t*>(std::realloc(buffer_, new_size)); if (new_buffer == NULL) { throw std::bad_alloc(); } rBase_ = new_buffer + (rBase_ - buffer_); rBound_ = new_buffer + (rBound_ - buffer_); wBase_ = new_buffer + (wBase_ - buffer_); wBound_ = new_buffer + new_size; buffer_ = new_buffer; bufferSize_ = new_size; If old bufferSize_ is lager than 2gb, then calculating new size will overflow. i.e. if bufferSize_ = 3355443200, then new buffer size will be 2415919104, which is less than old size. However, avail = available_write() + (new_size - bufferSize_) overflows again, so we will end up with an shrinked buffer. What is worse is that after wBase_ = new_buffer + (wBase_ - buffer_); wBound_ = new_buffer + new_size; wBase_ stays the same, but wBound_ becomes lower than it. What happens next is that uint32_t avail = available_write() may overflow every time subsequently. and thrift writes to unknown memory. -- This message was sent by Atlassian JIRA (v6.3.4#6332)