Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Fix heap overflow #450

Closed
wants to merge 1 commit into from
Closed

Fix heap overflow #450

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 4 additions & 4 deletions src/object/class.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -728,9 +728,9 @@ void* instance_holder::allocate(PyObject* self_, std::size_t holder_offset, std:
{
assert(PyType_IsSubtype(Py_TYPE(Py_TYPE(self_)), &class_metatype_object));
objects::instance<>* self = (objects::instance<>*)self_;
int total_size_needed = holder_offset + holder_size + alignment - 1;

std::ptrdiff_t total_size_needed = holder_offset + holder_size + alignment - 1;

if (-Py_SIZE(self) >= total_size_needed)
{
// holder_offset should at least point into the variable-sized part
Expand All @@ -756,7 +756,7 @@ void* instance_holder::allocate(PyObject* self_, std::size_t holder_offset, std:
//this has problems for x -> max(void *)
//const size_t padding = alignment - ((x + sizeof(alignment_marker_t)) % alignment);
//only works for alignments with alignments of powers of 2, but no edge conditions
const uintptr_t padding = alignment == 1 ? 0 : ( alignment - (x & (alignment - 1)) );
const uintptr_t padding = (x & (alignment - 1)) ? ( alignment - (x & (alignment - 1)) ) : 0;
const size_t aligned_offset = sizeof(alignment_marker_t) + padding;
void* const aligned_storage = (char *)base_storage + aligned_offset;
BOOST_ASSERT((char *) aligned_storage + holder_size <= (char *)base_storage + base_allocation);
Expand Down
Loading