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Update double freed problem #5

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Update double freed problem #5

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543e2db
attempt to workaround double free by adding memory cookie
naitro2010 Jul 25, 2025
26f1754
add reallocate and scrap heap support
naitro2010 Jul 25, 2025
7b0f310
Merge pull request #4 from naitro2010/double-free-workaround
AndbGame Jul 25, 2025
c96e373
compile
AndrejAndb Jul 25, 2025
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76 changes: 50 additions & 26 deletions src/patches/memorymanager.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -80,34 +80,58 @@ namespace

namespace MemoryManager
{
void* Allocate(RE::MemoryManager*, std::size_t a_size, std::uint32_t a_alignment, bool a_alignmentRequired)
{
if (a_size > 0)
return a_alignmentRequired ?
scalable_aligned_malloc(a_size, a_alignment) :
scalable_malloc(a_size);
else
return g_trash;
void *Allocate(RE::MemoryManager *, std::size_t a_size, std::uint32_t a_alignment, bool a_alignmentRequired) {
if (a_size > 0) {
void *return_ptr = a_alignmentRequired ? scalable_aligned_malloc(a_size + 0x100, a_alignment) : scalable_malloc(a_size + 0x100);
uint64_t *return_ptr_offset = (uint64_t *) (((uint64_t) return_ptr) + 0x100);
*(uint64_t *) return_ptr = 0x1337DEADDEAD1337;
//logger::trace("MemoryManagerStats::Allocate ptr {} (internal ptr {}) diff {}.", reinterpret_cast<uintptr_t>(return_ptr_offset), reinterpret_cast<uintptr_t>(return_ptr), reinterpret_cast<uintptr_t>(return_ptr_offset) - reinterpret_cast<uintptr_t>(return_ptr));
return (void *) return_ptr_offset;
}
else return g_trash;
}

void Deallocate(RE::MemoryManager*, void* a_mem, bool a_alignmentRequired)
{
if (a_mem != g_trash)
a_alignmentRequired ?
scalable_aligned_free(a_mem) :
scalable_free(a_mem);
void Deallocate(RE::MemoryManager *, void *a_mem, bool a_alignmentRequired) {
if (a_mem != g_trash) {
if (a_mem) {
std::atomic<uint64_t> *original_mem = (std::atomic<uint64_t> *) (((uint64_t) a_mem) - 0x100);
uint64_t expected = 0x1337DEADDEAD1337;
if (original_mem->compare_exchange_strong(expected, (uint64_t) 0x0)) {
//logger::trace("MemoryManagerStats::Deallocate ptr {} (internal ptr {}) diff {}.", reinterpret_cast<uintptr_t>(a_mem), reinterpret_cast<uintptr_t>(original_mem), reinterpret_cast<uintptr_t>(a_mem) - reinterpret_cast<uintptr_t>(original_mem));
a_alignmentRequired ? scalable_aligned_free(original_mem) : scalable_free(original_mem);
}
else {
logger::warn("MemoryManager::Deallocate error 202: already deallocated for addr {}.", reinterpret_cast<uintptr_t>(a_mem));
}
}
}
}

void* Reallocate(RE::MemoryManager* a_self, void* a_oldMem, std::size_t a_newSize, std::uint32_t a_alignment, bool a_alignmentRequired)
{
void *Reallocate(RE::MemoryManager *a_self, void *a_oldMem, std::size_t a_newSize, std::uint32_t a_alignment,
bool a_alignmentRequired) {
if (a_oldMem == g_trash)
return Allocate(a_self, a_newSize, a_alignment, a_alignmentRequired);
else
return a_alignmentRequired ?
scalable_aligned_realloc(a_oldMem, a_newSize, a_alignment) :
scalable_realloc(a_oldMem, a_newSize);
else if (a_oldMem) {
void *original_mem = (std::atomic<uint64_t> *) (((uint64_t) a_oldMem) - 0x100);

//logger::trace("MemoryManagerStats::Reallocate ptr {} (internal ptr {}) diff {}.", reinterpret_cast<uintptr_t>(a_oldMem), reinterpret_cast<uintptr_t>(original_mem), reinterpret_cast<uintptr_t>(a_oldMem) - reinterpret_cast<uintptr_t>(original_mem));

std::atomic<uint64_t> *original_cookie = (std::atomic<uint64_t> *) (((uint64_t) a_oldMem) - 0x100);
uint64_t expected = 0x1337DEADDEAD1337;
if (original_cookie->compare_exchange_strong(expected, (uint64_t) 0x1337DEADDEAD1337)) {
void *new_mem = a_alignmentRequired ? scalable_aligned_realloc(original_mem, a_newSize + 0x100, a_alignment)
: scalable_realloc(original_mem, a_newSize + 0x100);
*(uint64_t *) new_mem = (uint64_t) 0x1337DEADDEAD1337;
return (void *) (((uint64_t) new_mem) + 0x100);
}
else
{
logger::warn("MemoryManager::Reallocate error 302: already deallocated for addr {}.", reinterpret_cast<uintptr_t>(a_oldMem));
return g_trash;
}
}
return g_trash;
}

void ReplaceAllocRoutines()
{
using tuple_t = std::tuple<REL::ID, std::size_t, void*>;
Expand Down Expand Up @@ -158,9 +182,9 @@ namespace
{
void* Allocate(RE::ScrapHeap*, std::size_t a_size, std::size_t a_alignment)
{
return a_size > 0 ?
scalable_aligned_malloc(a_size, a_alignment) :
g_trash;
// TODO: std::size_t -> std::uint32_t
//logger::trace("ScrapHeap::Allocate a_size: {}; a_alignment: {}; static_cast a_alignment: {}.", a_size, a_alignment, static_cast<std::uint32_t>(a_alignment));
return MemoryManager::Allocate(nullptr, a_size, static_cast<std::uint32_t>(a_alignment), true);
}

RE::ScrapHeap* Ctor(RE::ScrapHeap* a_this)
Expand All @@ -172,8 +196,8 @@ namespace

void Deallocate(RE::ScrapHeap*, void* a_mem)
{
if (a_mem != g_trash)
scalable_aligned_free(a_mem);
//logger::trace("ScrapHeap::Deallocate {}.", reinterpret_cast<uintptr_t>(a_mem));
return MemoryManager::Deallocate(nullptr,a_mem,true);
}

void WriteHooks()
Expand Down