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Loader: Clean up 3dsx loader a bit, fixing a potential buffer overrun

This commit is contained in:
Yuri Kunde Schlesner 2015-07-09 17:11:09 -03:00
parent fdbf410bd7
commit 34f5f77507
1 changed files with 16 additions and 13 deletions
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29
src/core/loader/3dsx.cpp
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@ -19,7 +19,7 @@
namespace Loader {
/**
/*
* File layout:
* - File header
* - Code, rodata and data relocation table headers
@ -39,13 +39,16 @@ namespace Loader {
* The entrypoint is always the start of the code segment.
* The BSS section must be cleared manually by the application.
*/
enum THREEDSX_Error {
ERROR_NONE = 0,
ERROR_READ = 1,
ERROR_FILE = 2,
ERROR_ALLOC = 3
};
static const u32 RELOCBUFSIZE = 512;
static const unsigned int NUM_SEGMENTS = 3;
// File header
#pragma pack(1)
@ -116,13 +119,13 @@ static THREEDSX_Error Load3DSXFile(FileUtil::IOFile& file, u32 base_addr)
loadinfo.seg_sizes[1] = (hdr.rodata_seg_size + 0xFFF) &~0xFFF;
loadinfo.seg_sizes[2] = (hdr.data_seg_size + 0xFFF) &~0xFFF;
u32 offsets[2] = { loadinfo.seg_sizes[0], loadinfo.seg_sizes[0] + loadinfo.seg_sizes[1] };
u32 n_reloc_tables = hdr.reloc_hdr_size / 4;
std::vector<u8> all_mem(loadinfo.seg_sizes[0] + loadinfo.seg_sizes[1] + loadinfo.seg_sizes[2] + 3 * n_reloc_tables);
u32 n_reloc_tables = hdr.reloc_hdr_size / sizeof(u32);
std::vector<u8> program_image(loadinfo.seg_sizes[0] + loadinfo.seg_sizes[1] + loadinfo.seg_sizes[2]);
loadinfo.seg_addrs[0] = base_addr;
loadinfo.seg_addrs[1] = loadinfo.seg_addrs[0] + loadinfo.seg_sizes[0];
loadinfo.seg_addrs[2] = loadinfo.seg_addrs[1] + loadinfo.seg_sizes[1];
loadinfo.seg_ptrs[0] = &all_mem[0];
loadinfo.seg_ptrs[0] = program_image.data();
loadinfo.seg_ptrs[1] = loadinfo.seg_ptrs[0] + loadinfo.seg_sizes[0];
loadinfo.seg_ptrs[2] = loadinfo.seg_ptrs[1] + loadinfo.seg_sizes[1];
@ -130,10 +133,9 @@ static THREEDSX_Error Load3DSXFile(FileUtil::IOFile& file, u32 base_addr)
file.Seek(hdr.header_size, SEEK_SET);
// Read the relocation headers
u32* relocs = (u32*)(loadinfo.seg_ptrs[2] + hdr.data_seg_size);
for (unsigned current_segment : {0, 1, 2}) {
size_t size = n_reloc_tables * 4;
std::vector<u32> relocs(n_reloc_tables * NUM_SEGMENTS);
for (unsigned int current_segment = 0; current_segment < NUM_SEGMENTS; ++current_segment) {
size_t size = n_reloc_tables * sizeof(u32);
if (file.ReadBytes(&relocs[current_segment * n_reloc_tables], size) != size)
return ERROR_READ;
}
@ -150,7 +152,7 @@ static THREEDSX_Error Load3DSXFile(FileUtil::IOFile& file, u32 base_addr)
memset((char*)loadinfo.seg_ptrs[2] + hdr.data_seg_size - hdr.bss_size, 0, hdr.bss_size);
// Relocate the segments
for (unsigned current_segment : {0, 1, 2}) {
for (unsigned int current_segment = 0; current_segment < NUM_SEGMENTS; ++current_segment) {
for (unsigned current_segment_reloc_table = 0; current_segment_reloc_table < n_reloc_tables; current_segment_reloc_table++) {
u32 n_relocs = relocs[current_segment * n_reloc_tables + current_segment_reloc_table];
if (current_segment_reloc_table >= 2) {
@ -158,7 +160,7 @@ static THREEDSX_Error Load3DSXFile(FileUtil::IOFile& file, u32 base_addr)
file.Seek(n_relocs*sizeof(THREEDSX_Reloc), SEEK_CUR);
continue;
}
static THREEDSX_Reloc reloc_table[RELOCBUFSIZE];
THREEDSX_Reloc reloc_table[RELOCBUFSIZE];
u32* pos = (u32*)loadinfo.seg_ptrs[current_segment];
const u32* end_pos = pos + (loadinfo.seg_sizes[current_segment] / 4);
@ -177,7 +179,7 @@ static THREEDSX_Error Load3DSXFile(FileUtil::IOFile& file, u32 base_addr)
pos += table.skip;
s32 num_patches = table.patch;
while (0 < num_patches && pos < end_pos) {
u32 in_addr = (char*)pos - (char*)&all_mem[0];
u32 in_addr = (u8*)pos - program_image.data();
u32 addr = TranslateAddr(*pos, &loadinfo, offsets);
LOG_TRACE(Loader, "Patching %08X <-- rel(%08X,%d) (%08X)\n",
base_addr + in_addr, addr, current_segment_reloc_table, *pos);
@ -200,7 +202,7 @@ static THREEDSX_Error Load3DSXFile(FileUtil::IOFile& file, u32 base_addr)
}
// Write the data
memcpy(Memory::GetPointer(base_addr), &all_mem[0], loadinfo.seg_sizes[0] + loadinfo.seg_sizes[1] + loadinfo.seg_sizes[2]);
memcpy(Memory::GetPointer(base_addr), program_image.data(), program_image.size());
LOG_DEBUG(Loader, "code size: 0x%X", loadinfo.seg_sizes[0]);
LOG_DEBUG(Loader, "rodata size: 0x%X", loadinfo.seg_sizes[1]);
@ -235,7 +237,8 @@ ResultStatus AppLoader_THREEDSX::Load() {
// Attach the default resource limit (APPLICATION) to the process
Kernel::g_current_process->resource_limit = Kernel::ResourceLimit::GetForCategory(Kernel::ResourceLimitCategory::APPLICATION);
Load3DSXFile(*file, Memory::PROCESS_IMAGE_VADDR);
if (Load3DSXFile(*file, Memory::PROCESS_IMAGE_VADDR) != ERROR_NONE)
return ResultStatus::Error;
Kernel::g_current_process->Run(Memory::PROCESS_IMAGE_VADDR, 48, Kernel::DEFAULT_STACK_SIZE);