diff --git a/.gitmodules b/.gitmodules index 83f3f3f..add8634 100644 --- a/.gitmodules +++ b/.gitmodules @@ -1,3 +1,3 @@ [submodule "deps/vmprofiler"] path = deps/vmprofiler - url = https://githacks.org/vmp3/vmprofiler + url = https://git.back.engineering/Manifold/vmprofiler diff --git a/cmake.toml b/cmake.toml index 9f6f6c6..d58f890 100644 --- a/cmake.toml +++ b/cmake.toml @@ -2,7 +2,6 @@ name = "vmemu" [subdir.deps] -[subdir.tools] [target.vmemu] type = "static" diff --git a/deps/vmprofiler b/deps/vmprofiler index b01ba0e..fa64967 160000 --- a/deps/vmprofiler +++ b/deps/vmprofiler @@ -1 +1 @@ -Subproject commit b01ba0ef77198161b14c666f99c5c0cd073bda0f +Subproject commit fa64967bd77983b8fd3affc1de196a0d525adb52 diff --git a/include/vmemu_t.hpp b/include/vmemu_t.hpp index b833e3d..5a72e40 100644 --- a/include/vmemu_t.hpp +++ b/include/vmemu_t.hpp @@ -1,6 +1,7 @@ #pragma once #include +#include #include #include #include @@ -14,12 +15,18 @@ #define STACK_BASE 0xFFFF000000000000 namespace vm { +namespace reg_names +{ + const std::array prefixes = {{"Red", "Blue", "Pink", "Green", "Orange", "Yellow", "Black", "White"}}; + const std::array suffixes = {{"Crewmate", "Engineer", "Imposter", "Shapeshifter"}}; +} class emu_t { public: explicit emu_t(vm::vmctx_t* vm_ctx); ~emu_t(); bool init(); bool emulate(std::uint32_t vmenter_rva, vm::instrs::vrtn_t& vrtn); + const bool m_log_instructions = false; private: uc_engine* uc; @@ -61,7 +68,9 @@ class emu_t { /// /// /// - static bool code_exec_callback(uc_engine* uc, uint64_t address, uint32_t size, + static bool code_exec_callback(uc_engine* uc, + uint64_t address, + uint32_t size, emu_t* obj); /// @@ -74,8 +83,10 @@ class emu_t { /// /// /// - static bool branch_pred_spec_exec(uc_engine* uc, uint64_t address, - uint32_t size, emu_t* obj); + static bool branch_pred_spec_exec(uc_engine* uc, + uint64_t address, + uint32_t size, + emu_t* obj); /// /// invalid memory access handler. no runtime values can possibly effect the @@ -88,8 +99,12 @@ class emu_t { /// size of the memory access... /// value being read... /// emu_t object pointer... - static void invalid_mem(uc_engine* uc, uc_mem_type type, uint64_t address, - int size, int64_t value, emu_t* obj); + static void invalid_mem(uc_engine* uc, + uc_mem_type type, + uint64_t address, + int size, + int64_t value, + emu_t* obj); /// /// interrupt callback for unicorn engine. this is used to advance rip over diff --git a/src/vmemu_t.cpp b/src/vmemu_t.cpp index 03b06a7..982f871 100644 --- a/src/vmemu_t.cpp +++ b/src/vmemu_t.cpp @@ -1,8 +1,14 @@ #include #include +#include +#ifdef _WIN32 +#pragma warning(disable : 4477) +#endif() + +int g_new_delete_tracker; namespace vm { -emu_t::emu_t(vm::vmctx_t* vm_ctx) : m_vm(vm_ctx) {} +emu_t::emu_t(vm::vmctx_t* vm_ctx) : m_vm(vm_ctx) {}; emu_t::~emu_t() { if (uc) uc_close(uc); @@ -83,21 +89,20 @@ bool emu_t::emulate(std::uint32_t vmenter_rva, vm::instrs::vrtn_t& vrtn) { return false; } - cc_trace.m_vip = cc_blk->m_vm.vip; - cc_trace.m_vsp = cc_blk->m_vm.vsp; - - std::printf("> beginning execution at = %p\n", rip); + std::printf("> beginning execution at = %p (%p)\n", rip, rip - m_vm->m_module_base + m_vm->m_image_base); + std::printf("vsp: %s, vip: %s\n", ZydisRegisterGetString(cc_blk->m_vm.vsp), + ZydisRegisterGetString(cc_blk->m_vm.vip)); if ((err = uc_emu_start(uc, rip, 0ull, 0ull, 0ull))) { std::printf("> error starting emu... reason = %d\n", err); return false; } extract_branch_data(); - std::printf("> emulated blk_%p\n\n", cc_blk->m_vip.img_base); + std::printf("> emulated blk_%p\n\n", cc_blk->m_vip.img_based); // keep track of the emulated blocks... by their addresses... - std::vector blk_addrs; - blk_addrs.push_back(blk.m_vip.rva + m_vm->m_module_base); + std::unordered_set blk_addrs; + blk_addrs.insert(blk.m_vip.rva + m_vm->m_module_base); // the vector containing the vblk's grows inside of this for loop // thus we cannot use an advanced for loop (which uses itr's)... @@ -107,8 +112,7 @@ bool emu_t::emulate(std::uint32_t vmenter_rva, vm::instrs::vrtn_t& vrtn) { // force the emulation of all branches... for (const auto br : blk.branches) { // only emulate blocks that havent been emulated before... - if (std::find(blk_addrs.begin(), blk_addrs.end(), br) != - blk_addrs.end()) + if (blk_addrs.find(br) != blk_addrs.end()) continue; std::uintptr_t vsp = 0ull; @@ -120,18 +124,25 @@ bool emu_t::emulate(std::uint32_t vmenter_rva, vm::instrs::vrtn_t& vrtn) { auto& new_blk = vrtn.m_blks.emplace_back(); new_blk.m_vip = {0ull, 0ull}; new_blk.m_vm = {blk.m_jmp.m_vm.vip, blk.m_jmp.m_vm.vsp}; + new_blk.is_branch = true; cc_blk = &new_blk; // emulate the branch... + // The stack is now set up with vsp pointing to the next branch to execute, therefore the jmp will go to that branch. uc_mem_write(uc, vsp, &br, sizeof br); - std::printf("> beginning execution at = %p\n", blk.m_jmp.rip); + std::printf("> beginning execution at = %p (%p)\n", blk.m_jmp.rip, + blk.m_jmp.rip - m_vm->m_module_base + m_vm->m_image_base); + std::printf("vsp: %s, vip: %s\n", ZydisRegisterGetString(cc_blk->m_vm.vsp), + ZydisRegisterGetString(cc_blk->m_vm.vip)); if ((err = uc_emu_start(uc, blk.m_jmp.rip, 0ull, 0ull, 0ull))) { std::printf("> error starting emu... reason = %d\n", err); return false; } extract_branch_data(); - std::printf("> emulated blk_%p\n", cc_blk->m_vip.img_base); + std::printf("> emulated blk_%p\n", cc_blk->m_vip.img_based); + // We needn't execute a block more than once for a single vrtn. + blk_addrs.insert(br); } } } @@ -139,71 +150,77 @@ bool emu_t::emulate(std::uint32_t vmenter_rva, vm::instrs::vrtn_t& vrtn) { // free all virtual code block virtual jmp information... std::for_each(vrtn.m_blks.begin(), vrtn.m_blks.end(), [&](vm::instrs::vblk_t& blk) { - if (blk.m_jmp.ctx) uc_context_free(blk.m_jmp.ctx); + if (blk.m_jmp.ctx) uct_context_free(blk.m_jmp.ctx); - if (blk.m_jmp.stack) delete[] blk.m_jmp.stack; + if (blk.m_jmp.stack) delete[] blk.m_jmp.stack; if (blk.m_jmp.stack) g_new_delete_tracker--; }); return true; } void emu_t::extract_branch_data() { - auto br_info = could_have_jcc(cc_blk->m_vinstrs); - if (br_info.has_value()) { - auto [br1, br2] = br_info.value(); - // convert to absolute addresses... - br1 -= m_vm->m_image_base; - br2 -= m_vm->m_image_base; - br1 += m_vm->m_module_base; - br2 += m_vm->m_module_base; - - auto br1_legit = legit_branch(*cc_blk, br1); - auto br2_legit = legit_branch(*cc_blk, br2); - std::printf("> br1 legit: %d, br2 legit: %d\n", br1_legit, br2_legit); - - if (br1_legit && br2_legit) { - std::printf("> virtual jcc uncovered... br1 = %p, br2 = %p\n", br1, br2); - cc_blk->branch_type = vm::instrs::vbranch_type::jcc; - cc_blk->branches.push_back(br1); - cc_blk->branches.push_back(br2); - } else if (br1_legit || br2_legit) { - std::printf("> absolute virtual jmp uncovered... branch = %p\n", - br1_legit ? br1 : br2); - cc_blk->branch_type = vm::instrs::vbranch_type::absolute; - cc_blk->branches.push_back(br1_legit ? br1 : br2); - } else { - std::printf("> unknown branch type...\n"); + if (cc_blk->m_vinstrs.empty()) + { + cc_blk->branch_type = vm::instrs::vbranch_type::none; + return; } - } else if (cc_blk->m_vinstrs.back().mnemonic == - vm::instrs::mnemonic_t::vmexit) { - cc_blk->branch_type = vm::instrs::vbranch_type::none; - } else if (cc_blk->m_vinstrs.back().mnemonic == vm::instrs::mnemonic_t::jmp) { - // see if there is 1 lconst... - if (auto last_lconst = std::find_if( - cc_blk->m_vinstrs.rbegin(), cc_blk->m_vinstrs.rend(), - [&](vm::instrs::vinstr_t& vinstr) -> bool { - return vinstr.mnemonic == vm::instrs::mnemonic_t::lconst && - vinstr.imm.size == 64; - }); - last_lconst != cc_blk->m_vinstrs.rend()) { - const auto imm_img_based = last_lconst->imm.val; - const auto imm_mod_based = - (imm_img_based - m_vm->m_image_base) + m_vm->m_module_base; - - // check to see if the imm is inside of the module... and if the ptr lands - // inside of an executable section... then lastly check to see if its a - // legit branch or not... - if (imm_img_based >= m_vm->m_image_base && - imm_img_based < m_vm->m_image_base + m_vm->m_image_size && - vm::utils::scn::executable(m_vm->m_module_base, imm_mod_based)) { - cc_blk->branches.push_back(imm_mod_based); + auto br_info = could_have_jcc(cc_blk->m_vinstrs); + if (br_info.has_value()) { + auto [br1, br2] = br_info.value(); + // convert to absolute addresses... + br1 -= m_vm->m_image_base; + br2 -= m_vm->m_image_base; + br1 += m_vm->m_module_base; + br2 += m_vm->m_module_base; + + auto br1_legit = legit_branch(*cc_blk, br1); + auto br2_legit = legit_branch(*cc_blk, br2); + std::printf("> br1 legit: %d, br2 legit: %d\n", br1_legit, br2_legit); + + if (br1_legit && br2_legit) { + std::printf("> virtual jcc uncovered... br1 = %p, br2 = %p\n", br1, br2); + cc_blk->branch_type = vm::instrs::vbranch_type::jcc; + cc_blk->branches.push_back(br1); + cc_blk->branches.push_back(br2); + } else if (br1_legit || br2_legit) { + std::printf("> absolute virtual jmp uncovered... branch = %p\n", + br1_legit ? br1 : br2); cc_blk->branch_type = vm::instrs::vbranch_type::absolute; - } - } else { - std::printf("> jump table detected... review instruction stream...\n"); - uc_emu_stop(uc); + cc_blk->branches.push_back(br1_legit ? br1 : br2); + } else { + std::printf("> unknown branch type...\n"); + } + } else if (cc_blk->m_vinstrs.back().mnemonic == + vm::instrs::mnemonic_t::vmexit) { + cc_blk->branch_type = vm::instrs::vbranch_type::none; + } else if (cc_blk->m_vinstrs.back().mnemonic == vm::instrs::mnemonic_t::jmp) { + // see if there is 1 lconst... + if (auto last_lconst = std::find_if( + cc_blk->m_vinstrs.rbegin(), cc_blk->m_vinstrs.rend(), + [&](vm::instrs::vinstr_t& vinstr) -> bool { + return vinstr.mnemonic == vm::instrs::mnemonic_t::lconst && + vinstr.imm.size == 64; + }); + last_lconst != cc_blk->m_vinstrs.rend()) { + const auto imm_img_based = last_lconst->imm.val; + const auto imm_mod_based = + (imm_img_based - m_vm->m_image_base) + m_vm->m_module_base; + + // check to see if the imm is inside of the module... and if the ptr lands + // inside of an executable section... then lastly check to see if its a + // legit branch or not... + if (imm_img_based >= m_vm->m_image_base && + imm_img_based < m_vm->m_image_base + m_vm->m_image_size && + vm::utils::scn::executable(m_vm->m_module_base, imm_mod_based)) { + cc_blk->branches.push_back(imm_mod_based); + cc_blk->branch_type = vm::instrs::vbranch_type::absolute; + std::printf("> absolute virtual jmp uncovered... branch = %p\n", imm_mod_based); + } + } else { + std::printf("> jump table detected... review instruction stream...\n"); + uc_emu_stop(uc); + } } - } } void emu_t::int_callback(uc_engine* uc, std::uint32_t intno, emu_t* obj) { @@ -252,18 +269,13 @@ bool emu_t::branch_pred_spec_exec(uc_engine* uc, uint64_t address, return false; } - if (instr.mnemonic == ZYDIS_MNEMONIC_INVALID) return false; - + if (instr.mnemonic == ZYDIS_MNEMONIC_INVALID) {std::printf("> bad instruction\n"); return false;} uc_context* ctx; - uc_context_alloc(uc, &ctx); + uct_context_alloc(uc, &ctx); uc_context_save(uc, ctx); - // if this is the first instruction of this handler then save the stack... - if (!obj->cc_trace.m_instrs.size()) { - obj->cc_trace.m_stack = new std::uint8_t[STACK_SIZE]; - uc_mem_read(uc, STACK_BASE, obj->cc_trace.m_stack, STACK_SIZE); - } - + if (obj->cc_trace.m_instrs.empty()) + obj->cc_trace.m_begin = address; obj->cc_trace.m_instrs.push_back({instr, ctx}); // RET or JMP REG means the end of a vm handler... @@ -274,7 +286,7 @@ bool emu_t::branch_pred_spec_exec(uc_engine* uc, uint64_t address, // makes it easier for profiles to be correct... vm::instrs::deobfuscate(obj->cc_trace); - // find the last MOV REG, DWORD PTR [VIP] in the instruction stream, then +/* // find the last MOV REG, DWORD PTR [VIP] in the instruction stream, then // remove any instructions from this instruction to the JMP/RET... const auto rva_fetch = std::find_if( obj->cc_trace.m_instrs.rbegin(), obj->cc_trace.m_instrs.rend(), @@ -285,21 +297,26 @@ bool emu_t::branch_pred_spec_exec(uc_engine* uc, uint64_t address, i.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER && i.operands[1].type == ZYDIS_OPERAND_TYPE_MEMORY && i.operands[1].mem.base == vip && i.operands[1].size == 32; - }); + }); if (rva_fetch != obj->cc_trace.m_instrs.rend()) + { + for (auto itr = (rva_fetch + 1).base(); itr < obj->cc_trace.m_instrs.end(); itr++) + { + uct_context_free(itr->m_cpu); + } obj->cc_trace.m_instrs.erase((rva_fetch + 1).base(), obj->cc_trace.m_instrs.end()); + } */ const auto vinstr = vm::instrs::determine(obj->cc_trace); // -- free the trace since we will start a new one... std::for_each(obj->cc_trace.m_instrs.begin(), obj->cc_trace.m_instrs.end(), [&](const vm::instrs::emu_instr_t& instr) { - uc_context_free(instr.m_cpu); + uct_context_free(instr.m_cpu); }); - delete[] obj->cc_trace.m_stack; obj->cc_trace.m_instrs.clear(); if (vinstr.mnemonic != vm::instrs::mnemonic_t::jmp) { @@ -310,6 +327,9 @@ bool emu_t::branch_pred_spec_exec(uc_engine* uc, uint64_t address, if (vinstr.imm.size != 8 || vinstr.imm.val > 8 * VIRTUAL_REGISTER_COUNT) uc_emu_stop(uc); + // stop if done or if instruction is invalid + if (vinstr.mnemonic == instrs::mnemonic_t::unknown) + uc_emu_stop(uc); // -- stop after 10 legit SREG's... if (++obj->m_sreg_cnt == 10) uc_emu_stop(uc); } @@ -335,12 +355,14 @@ bool emu_t::code_exec_callback(uc_engine* uc, uint64_t address, uint32_t size, if (instr.mnemonic == ZYDIS_MNEMONIC_INVALID) return false; uc_context* ctx; - uc_context_alloc(uc, &ctx); + uct_context_alloc(uc, &ctx); uc_context_save(uc, ctx); // if this is the first instruction of this handler then save the stack... if (!obj->cc_trace.m_instrs.size()) { - obj->cc_trace.m_stack = new std::uint8_t[STACK_SIZE]; + obj->cc_trace.m_vip = obj->cc_blk->m_vm.vip; + obj->cc_trace.m_vsp = obj->cc_blk->m_vm.vsp; + obj->cc_trace.m_stack = new std::uint8_t[STACK_SIZE]; g_new_delete_tracker++; obj->cc_trace.m_begin = address; uc_mem_read(uc, STACK_BASE, obj->cc_trace.m_stack, STACK_SIZE); } @@ -357,7 +379,9 @@ bool emu_t::code_exec_callback(uc_engine* uc, uint64_t address, uint32_t size, // find the last MOV REG, DWORD PTR [VIP] in the instruction stream, then // remove any instructions from this instruction to the JMP/RET... - const auto rva_fetch = std::find_if( + // This may be more performant and elegant, but it fucks my new jmp profiler. + // I will keep it in as a comment for now in case I can make a jmp profiler compatible with this. +/* const auto rva_fetch = std::find_if( obj->cc_trace.m_instrs.rbegin(), obj->cc_trace.m_instrs.rend(), [& vip = obj->cc_trace.m_vip]( const vm::instrs::emu_instr_t& instr) -> bool { @@ -369,11 +393,17 @@ bool emu_t::code_exec_callback(uc_engine* uc, uint64_t address, uint32_t size, }); if (rva_fetch != obj->cc_trace.m_instrs.rend()) + { + for (auto itr = (rva_fetch + 1).base(); itr < --obj->cc_trace.m_instrs.end(); ++itr) + { + uct_context_free(itr->m_cpu); + } obj->cc_trace.m_instrs.erase((rva_fetch + 1).base(), - obj->cc_trace.m_instrs.end()); + --obj->cc_trace.m_instrs.end()); + } */ // set the virtual code block vip address information... - if (!obj->cc_blk->m_vip.rva || !obj->cc_blk->m_vip.img_base) { + if (!obj->cc_blk->m_vip.rva || !obj->cc_blk->m_vip.img_based) { // find the last write done to VIP... auto vip_write = std::find_if( obj->cc_trace.m_instrs.rbegin(), obj->cc_trace.m_instrs.rend(), @@ -385,28 +415,37 @@ bool emu_t::code_exec_callback(uc_engine* uc, uint64_t address, uint32_t size, }); uc_context* backup; - uc_context_alloc(uc, &backup); + uct_context_alloc(uc, &backup); uc_context_save(uc, backup); - uc_context_restore(uc, (--vip_write)->m_cpu); - + uc_context_restore(uc, vip_write->m_cpu); + std::uintptr_t vip_addr = 0ull; uc_reg_read(uc, vm::instrs::reg_map[obj->cc_trace.m_vip], &vip_addr); obj->cc_blk->m_vip.rva = vip_addr -= obj->m_vm->m_module_base; - obj->cc_blk->m_vip.img_base = vip_addr += obj->m_vm->m_image_base; + obj->cc_blk->m_vip.img_based = vip_addr += obj->m_vm->m_image_base; uc_context_restore(uc, backup); - uc_context_free(backup); + uct_context_free(backup); } else { const auto vinstr = vm::instrs::determine(obj->cc_trace); if (vinstr.mnemonic != vm::instrs::mnemonic_t::unknown) { - if (vinstr.imm.has_imm) - std::printf("> %s %p\n", - vm::instrs::get_profile(vinstr.mnemonic)->name.c_str(), - vinstr.imm.val); - else - std::printf("> %s\n", - vm::instrs::get_profile(vinstr.mnemonic)->name.c_str()); + if (obj->m_log_instructions) { + std::printf("%p: ", obj->cc_trace.m_begin + obj->m_vm->m_image_base - obj->m_vm->m_module_base); + if (vinstr.imm.has_imm) + if (vinstr.mnemonic == instrs::mnemonic_t::lreg || vinstr.mnemonic == instrs::mnemonic_t::sreg) + std::printf("> %s %s_%s\n", + vm::instrs::get_profile(vinstr.mnemonic)->name.c_str(), + vm::reg_names::prefixes[(vinstr.imm.val / 8) % 8].c_str(), + vm::reg_names::suffixes[(vinstr.imm.val / 8) / 8].c_str()); + else + std::printf("> %s %p\n", + vm::instrs::get_profile(vinstr.mnemonic)->name.c_str(), + vinstr.imm.val); + else + std::printf("> %s\n", + vm::instrs::get_profile(vinstr.mnemonic)->name.c_str()); + } } else { zydis_rtn_t inst_stream; std::for_each(obj->cc_trace.m_instrs.begin(), @@ -419,19 +458,18 @@ bool emu_t::code_exec_callback(uc_engine* uc, uint64_t address, uint32_t size, "> err: please define the following vm handler (at = %p):\n", (obj->cc_trace.m_begin - obj->m_vm->m_module_base) + obj->m_vm->m_image_base); - vm::utils::print(inst_stream); uc_emu_stop(uc); return false; } - - if (obj->cc_blk->m_vinstrs.size()) { + //I don't think this if statement is neccesary + //if (obj->cc_blk->m_vinstrs.size()) { if (vinstr.mnemonic == vm::instrs::mnemonic_t::jmp) { uc_context *backup, *copy; // backup current unicorn-engine context... - uc_context_alloc(uc, &backup); - uc_context_alloc(uc, ©); + uct_context_alloc(uc, &backup); + uct_context_alloc(uc, ©); uc_context_save(uc, backup); // make a copy of the first cpu context of the jmp handler... @@ -440,36 +478,64 @@ bool emu_t::code_exec_callback(uc_engine* uc, uint64_t address, uint32_t size, // restore the unicorn-engine context... also free the backup... uc_context_restore(uc, backup); - uc_context_free(backup); + uct_context_free(backup); // set current code block virtual jmp instruction information... obj->cc_blk->m_jmp.ctx = copy; obj->cc_blk->m_jmp.rip = obj->cc_trace.m_begin; - obj->cc_blk->m_jmp.stack = new std::uint8_t[STACK_SIZE]; + obj->cc_blk->m_jmp.stack = new std::uint8_t[STACK_SIZE]; g_new_delete_tracker++; obj->cc_blk->m_jmp.m_vm = {obj->cc_trace.m_vip, obj->cc_trace.m_vsp}; std::memcpy(obj->cc_blk->m_jmp.stack, obj->cc_trace.m_stack, STACK_SIZE); } - + if (vinstr.mnemonic == vm::instrs::mnemonic_t::vmexit) + { + int i = 0; + for (const auto& instr_it : obj->cc_trace.m_instrs) + { + if ((instr_it.m_instr.mnemonic == ZYDIS_MNEMONIC_POP || + instr_it.m_instr.mnemonic == ZYDIS_MNEMONIC_POPFQ) && + instr_it.m_instr.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER) + { + if (i >= 16) + { + std::printf("[!] failed to parse vmexit pops\n"); + return false; + } + auto pushed_reg = instr_it.m_instr.operands[instr_it.m_instr.mnemonic == ZYDIS_MNEMONIC_POPFQ ? 2 : 0].reg.value; + if (std::find(obj->cc_blk->vmexit_pop_order.begin(), obj->cc_blk->vmexit_pop_order.begin() + i, pushed_reg) + != obj->cc_blk->vmexit_pop_order.begin() + i) + { + std::printf("[!] failed to parse vmexit pops\n"); + return false; + } + obj->cc_blk->vmexit_pop_order[i++] = pushed_reg; + } + } + if (i != 16) + { + std::printf("[!] failed to parse vmexit pops\n"); + return false; + } + } if (vinstr.mnemonic == vm::instrs::mnemonic_t::jmp || vinstr.mnemonic == vm::instrs::mnemonic_t::vmexit) uc_emu_stop(obj->uc); - } - + //} obj->cc_blk->m_vinstrs.push_back(vinstr); } // -- free the trace since we will start a new one... std::for_each(obj->cc_trace.m_instrs.begin(), obj->cc_trace.m_instrs.end(), [&](const vm::instrs::emu_instr_t& instr) { - uc_context_free(instr.m_cpu); + uct_context_free(instr.m_cpu); }); - delete[] obj->cc_trace.m_stack; + delete[] obj->cc_trace.m_stack; if (obj->cc_trace.m_stack) g_new_delete_tracker--; obj->cc_trace.m_instrs.clear(); } return true; -} + } void emu_t::invalid_mem(uc_engine* uc, uc_mem_type type, uint64_t address, int size, int64_t value, emu_t* obj) { @@ -509,9 +575,9 @@ bool emu_t::legit_branch(vm::instrs::vblk_t& vblk, std::uintptr_t branch_addr) { // make a backup of the current emulation state... uc_context* backup; - uc_context_alloc(uc, &backup); + uct_context_alloc(uc, &backup); uc_context_save(uc, backup); - std::uint8_t* stack = new std::uint8_t[STACK_SIZE]; + std::uint8_t* stack = new std::uint8_t[STACK_SIZE]; g_new_delete_tracker++; uc_mem_read(uc, STACK_BASE, stack, STACK_SIZE); // restore cpu and stack back to the virtual jump handler... @@ -523,6 +589,10 @@ bool emu_t::legit_branch(vm::instrs::vblk_t& vblk, std::uintptr_t branch_addr) { uc_reg_read(uc, UC_X86_REG_RIP, &rip); uc_reg_read(uc, vm::instrs::reg_map[vblk.m_vm.vsp], &vsp); uc_mem_write(uc, vsp, &branch_addr, sizeof branch_addr); + + // reset vsp and vip to their pre-jmp status in the current code trace + // this will be reset when the jmp instruction is emulated again + cc_trace.m_vsp = cc_blk->m_vm.vsp, cc_trace.m_vip = cc_blk->m_vm.vip; m_sreg_cnt = 0u; uc_emu_start(uc, rip, 0ull, 0ull, 0ull); @@ -530,8 +600,8 @@ bool emu_t::legit_branch(vm::instrs::vblk_t& vblk, std::uintptr_t branch_addr) { // restore original cpu and stack... uc_mem_write(uc, STACK_BASE, stack, STACK_SIZE); uc_context_restore(uc, backup); - uc_context_free(backup); - delete[] stack; + uct_context_free(backup); + delete[] stack; if (stack) g_new_delete_tracker--; // add normal execution callback back... uc_hook_del(uc, branch_pred_hook); @@ -564,31 +634,32 @@ std::optional> emu_t::could_have_jcc( return v.mnemonic == vm::instrs::mnemonic_t::lconst && v.imm.size == 64; }; - const auto lconst1 = - std::find_if(vinstrs.rbegin(), vinstrs.rend(), lconst64_chk); - - if (lconst1 == vinstrs.rend()) return {}; - - const auto lconst2 = std::find_if(lconst1 + 1, vinstrs.rend(), lconst64_chk); + static const auto valid_mem = [=](uintptr_t loc) + { + // check to see if the imm val is inside of the image... + if (loc > m_vm->m_image_base + m_vm->m_image_size || + loc < m_vm->m_image_base || + loc > m_vm->m_image_base + m_vm->m_image_size || + loc < m_vm->m_image_base) + return false; + return true; + }; + auto lconst1 = vinstrs.rbegin(); + do { + lconst1 = + std::find_if(lconst1 + 1, vinstrs.rend(), lconst64_chk); + if (lconst1 == vinstrs.rend()) return {}; + } while (!valid_mem(lconst1->imm.val)); + + auto lconst2 = lconst1; + do { + lconst2 = + std::find_if(lconst2 + 1, vinstrs.rend(), lconst64_chk); if (lconst2 == vinstrs.rend()) return {}; + } while (!valid_mem(lconst1->imm.val)); - // check to see if the imm val is inside of the image... - if (lconst1->imm.val > m_vm->m_image_base + m_vm->m_image_size || - lconst1->imm.val < m_vm->m_image_base || - lconst2->imm.val > m_vm->m_image_base + m_vm->m_image_size || - lconst2->imm.val < m_vm->m_image_base) - return {}; - - // check to see if the imm's points to something inside of an executable - // section... - if (!vm::utils::scn::executable( - m_vm->m_module_base, - (lconst1->imm.val - m_vm->m_image_base) + m_vm->m_module_base) || - !vm::utils::scn::executable( - m_vm->m_module_base, - (lconst2->imm.val - m_vm->m_image_base) + m_vm->m_module_base)) - return {}; + std::printf("possible jcc: %p, %p\n", lconst1->imm.val, lconst2->imm.val); return {{lconst1->imm.val, lconst2->imm.val}}; }