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/*
* (C) 2018 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include "fuzzers.h"
#include <botan/internal/mem_pool.h>
#include <botan/internal/bit_ops.h>
#include <vector>
#include <map>
#include <utility>
#include <stdlib.h>
namespace {
size_t compute_expected_alignment(size_t plen)
{
if(Botan::is_power_of_2(plen))
{
return plen;
}
else
{
return 8;
}
}
struct RawPage
{
public:
RawPage(void* p) : m_p(p) {}
~RawPage() { std::free(m_p); }
RawPage(const RawPage& other) = default;
RawPage& operator=(const RawPage& other) = default;
RawPage(RawPage&& other) : m_p(nullptr)
{
std::swap(m_p, other.m_p);
}
RawPage& operator=(RawPage&& other)
{
if(this != &other)
{
std::swap(m_p, other.m_p);
}
return (*this);
}
void* ptr() const { return m_p; }
private:
void* m_p;
};
std::vector<RawPage> allocate_raw_pages(size_t count, size_t page_size)
{
std::vector<RawPage> pages;
pages.reserve(count);
for(size_t i = 0; i != count; ++i)
{
void* ptr = nullptr;
int rc = ::posix_memalign(&ptr, page_size, page_size);
FUZZER_ASSERT_EQUAL(rc, 0);
if(ptr)
{
pages.push_back(RawPage(ptr));
}
}
return pages;
}
}
void fuzz(const uint8_t in[], size_t in_len)
{
const size_t page_count = 4;
const size_t page_size = 4096;
// static to avoid repeated allocations
static std::vector<RawPage> raw_mem = allocate_raw_pages(page_count, page_size);
std::vector<void*> mem_pages;
mem_pages.reserve(raw_mem.size());
for(size_t i = 0; i != raw_mem.size(); ++i)
mem_pages.push_back(raw_mem[i].ptr());
Botan::Memory_Pool pool(mem_pages, page_size);
std::map<uint8_t*, size_t> ptrs;
while(in_len > 0)
{
const uint8_t op = in[0] % 2;
size_t idx = (in[0] >> 1);
in += 1;
in_len -= 1;
if(in_len > 0 && idx < 4)
{
idx = idx * 256 + in[0];
in += 1;
in_len -= 1;
}
//printf("%d %d\n", op, idx);
if(op == 0)
{
const size_t plen = idx + 1; // ensure non-zero
uint8_t* p = static_cast<uint8_t*>(pool.allocate(plen));
if(p)
{
const size_t expected_alignment = compute_expected_alignment(plen);
const size_t alignment = reinterpret_cast<uintptr_t>(p) % expected_alignment;
if(alignment != 0)
{
FUZZER_WRITE_AND_CRASH("Pointer allocated non-aligned pointer " << static_cast<void*>(p) << " for len " << plen
<< " expected " << expected_alignment << " got " << alignment);
}
//printf("alloc %d -> %p\n", plen, p);
for(size_t i = 0; i != plen; ++i)
{
if(p[i] != 0)
{
FUZZER_WRITE_AND_CRASH("Pool gave out non-zeroed memory");
}
}
// verify it becomes zeroed later
std::memset(p, idx, plen);
auto insert = ptrs.insert(std::make_pair(p, plen));
if(insert.second == false)
{
FUZZER_WRITE_AND_CRASH("Pointer " << static_cast<void*>(p) << " already existed\n");
}
auto itr = insert.first;
// Verify this pointer doesn't overlap with the one before it
if(itr != ptrs.begin())
{
auto before = std::prev(itr);
auto ptr_before = *before;
if(ptr_before.first + ptr_before.second > p)
{
FUZZER_WRITE_AND_CRASH("Previous " << static_cast<void*>(ptr_before.first) << "/" << ptr_before.second <<
" overlaps with new " << static_cast<void*>(p));
}
}
auto after = std::next(itr);
if(after != ptrs.end())
{
if(p + plen > after->first)
{
FUZZER_WRITE_AND_CRASH("New " << static_cast<void*>(p) << "/" << plen
<< " overlaps following " << static_cast<void*>(after->first));
}
}
}
}
else if(op == 1)
{
if(ptrs.empty())
return;
size_t which_ptr = idx % ptrs.size();
auto itr = ptrs.begin();
while(which_ptr-- > 0)
{
++itr;
}
//printf("free %p %d\n", itr->first, itr->second);
FUZZER_ASSERT_TRUE(pool.deallocate(itr->first, itr->second));
ptrs.erase(itr);
}
}
}
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