rizin/librz/bin/p/bin_mz.c
Khairul Azhar Kasmiran c082ae82ae
Fix bin_elf import & symbol leak (#4490)
* Fix bin_elf import & symbol leak
* Allow bin plugins to set custom relocs free
2024-05-18 19:10:58 +08:00

280 lines
6.6 KiB
C

// SPDX-FileCopyrightText: 2015-2019 nodepad <nod3pad@gmail.com>
// SPDX-License-Identifier: LGPL-3.0-only
#include <rz_types.h>
#include <rz_bin.h>
#include <rz_lib.h>
#include "mz/mz.h"
/* half-magic */
#define HM(x) (int)((int)(x[0] << 8) | (int)(x[1]))
static Sdb *get_sdb(RzBinFile *bf) {
const struct rz_bin_mz_obj_t *bin;
if (bf && bf->o && bf->o->bin_obj) {
bin = (struct rz_bin_mz_obj_t *)bf->o->bin_obj;
if (bin && bin->kv) {
return bin->kv;
}
}
return NULL;
}
static bool knownHeaderBuffer(RzBuffer *b, ut16 offset) {
ut8 h[2];
if (rz_buf_read_at(b, offset, h, sizeof(h)) != sizeof(h)) {
return false;
}
if (!memcmp(h, "PE", 2)) {
if (offset + 0x20 < rz_buf_size(b)) {
if (rz_buf_read_at(b, offset + 0x18, h, sizeof(h)) != 2) {
return false;
}
if (!memcmp(h, "\x0b\x01", 2)) {
return true;
}
}
} else {
if (!memcmp(h, "NE", 2) || !memcmp(h, "LE", 2) || !memcmp(h, "LX", 2) || !memcmp(h, "PL", 2)) {
return true;
}
}
return false;
}
static bool checkEntrypointBuffer(RzBuffer *b) {
ut16 cs;
if (!rz_buf_read_le16_at(b, 0x16, &cs)) {
return false;
}
ut16 ip;
if (!rz_buf_read_le16_at(b, 0x14, &ip)) {
return false;
}
ut16 tmp;
if (!rz_buf_read_le16_at(b, 0x08, &tmp)) {
return false;
}
ut32 pa = ((tmp + cs) << 4) + ip;
/* A minimal MZ header is 0x1B bytes. Header length is measured in
* 16-byte paragraphs so the minimum header must occupy 2 paragraphs.
* This means that the entrypoint should be at least 0x20 unless someone
* cleverly fit a few instructions inside the header.
*/
pa &= 0xffff;
ut64 length = rz_buf_size(b);
if (pa >= 0x20 && pa + 1 < length) {
ut16 pe;
if (!rz_buf_read_le16_at(b, 0x3c, &pe)) {
return false;
}
if (pe + 2 < length && length > 0x104) {
ut8 h[2];
if (rz_buf_read_at(b, pe, h, 2) == 2) {
if (!memcmp(h, "PE", 2)) {
return false;
}
}
}
return true;
}
return false;
}
static bool check_buffer(RzBuffer *b) {
rz_return_val_if_fail(b, false);
ut64 b_size = rz_buf_size(b);
if (b_size <= 0x3d) {
return false;
}
// Check for MZ magic.
ut8 h[2];
if (rz_buf_read_at(b, 0, h, 2) != 2) {
return false;
}
if (memcmp(h, "MZ", 2)) {
return false;
}
// See if there is a new exe header.
ut16 new_exe_header_offset;
if (!rz_buf_read_le16_at(b, 0x3c, &new_exe_header_offset)) {
return false;
}
if (b_size > new_exe_header_offset + 2) {
if (knownHeaderBuffer(b, new_exe_header_offset)) {
return false;
}
}
// Raw plain MZ executable (watcom)
if (!checkEntrypointBuffer(b)) {
return false;
}
return true;
}
static bool load(RzBinFile *bf, RzBinObject *obj, RzBuffer *buf, Sdb *sdb) {
struct rz_bin_mz_obj_t *mz_obj = rz_bin_mz_new_buf(buf);
if (mz_obj) {
sdb_ns_set(sdb, "info", mz_obj->kv);
obj->bin_obj = mz_obj;
return true;
}
return false;
}
static void destroy(RzBinFile *bf) {
rz_bin_mz_free((struct rz_bin_mz_obj_t *)bf->o->bin_obj);
}
static RzBinAddr *binsym(RzBinFile *bf, RzBinSpecialSymbol type) {
RzBinAddr *mzaddr = NULL;
if (bf && bf->o && bf->o->bin_obj) {
switch (type) {
case RZ_BIN_SPECIAL_SYMBOL_MAIN:
mzaddr = rz_bin_mz_get_main_vaddr(bf->o->bin_obj);
break;
default:
break;
}
}
return mzaddr;
}
static RzPVector /*<RzBinAddr *>*/ *entries(RzBinFile *bf) {
RzBinAddr *ptr = NULL;
RzPVector *res = NULL;
if (!(res = rz_pvector_new(free))) {
return NULL;
}
ptr = rz_bin_mz_get_entrypoint(bf->o->bin_obj);
if (ptr) {
rz_pvector_push(res, ptr);
}
return res;
}
static RzPVector /*<RzBinSection *>*/ *sections(RzBinFile *bf) {
return rz_bin_mz_get_segments(bf->o->bin_obj);
}
static RzBinInfo *info(RzBinFile *bf) {
RzBinInfo *const ret = RZ_NEW0(RzBinInfo);
if (!ret) {
return NULL;
}
ret->file = strdup(bf->file);
ret->bclass = strdup("MZ");
ret->rclass = strdup("mz");
ret->os = strdup("DOS");
ret->arch = strdup("x86");
ret->machine = strdup("i386");
ret->type = strdup("EXEC (Executable file)");
ret->subsystem = strdup("DOS");
ret->bits = 16;
ret->dbg_info = 0;
ret->big_endian = false;
ret->has_crypto = false;
ret->has_canary = false;
ret->has_retguard = -1;
ret->has_nx = false;
ret->has_pi = false;
ret->has_va = true;
return ret;
}
static void header(RzBinFile *bf) {
const struct rz_bin_mz_obj_t *mz = (struct rz_bin_mz_obj_t *)bf->o->bin_obj;
eprintf("[0000:0000] Signature %c%c\n",
mz->dos_header->signature & 0xFF,
mz->dos_header->signature >> 8);
eprintf("[0000:0002] BytesInLastBlock 0x%04x\n",
mz->dos_header->bytes_in_last_block);
eprintf("[0000:0004] BlocksInFile 0x%04x\n",
mz->dos_header->blocks_in_file);
eprintf("[0000:0006] NumRelocs 0x%04x\n",
mz->dos_header->num_relocs);
eprintf("[0000:0008] HeaderParagraphs 0x%04x\n",
mz->dos_header->header_paragraphs);
eprintf("[0000:000a] MinExtraParagraphs 0x%04x\n",
mz->dos_header->min_extra_paragraphs);
eprintf("[0000:000c] MaxExtraParagraphs 0x%04x\n",
mz->dos_header->max_extra_paragraphs);
eprintf("[0000:000e] InitialSs 0x%04x\n",
mz->dos_header->ss);
eprintf("[0000:0010] InitialSp 0x%04x\n",
mz->dos_header->sp);
eprintf("[0000:0012] Checksum 0x%04x\n",
mz->dos_header->checksum);
eprintf("[0000:0014] InitialIp 0x%04x\n",
mz->dos_header->ip);
eprintf("[0000:0016] InitialCs 0x%04x\n",
mz->dos_header->cs);
eprintf("[0000:0018] RelocTableOffset 0x%04x\n",
mz->dos_header->reloc_table_offset);
eprintf("[0000:001a] OverlayNumber 0x%04x\n",
mz->dos_header->overlay_number);
}
static RzPVector /*<RzBinReloc *>*/ *relocs(RzBinFile *bf) {
RzPVector *ret = NULL;
RzBinReloc *rel = NULL;
const struct rz_bin_mz_reloc_t *relocs = NULL;
int i;
if (!bf || !bf->o || !bf->o->bin_obj) {
return NULL;
}
if (!(ret = rz_pvector_new((RzPVectorFree)rz_bin_reloc_free))) {
return NULL;
}
if (!(relocs = rz_bin_mz_get_relocs(bf->o->bin_obj))) {
return ret;
}
for (i = 0; !relocs[i].last; i++) {
if (!(rel = RZ_NEW0(RzBinReloc))) {
free((void *)relocs);
rz_pvector_free(ret);
return NULL;
}
rel->type = RZ_BIN_RELOC_16;
rel->vaddr = relocs[i].vaddr;
rel->paddr = relocs[i].paddr;
rz_pvector_push(ret, rel);
}
free((void *)relocs);
return ret;
}
RzBinPlugin rz_bin_plugin_mz = {
.name = "mz",
.desc = "MZ bin plugin",
.license = "MIT",
.get_sdb = &get_sdb,
.load_buffer = &load,
.destroy = &destroy,
.check_buffer = &check_buffer,
.binsym = &binsym,
.entries = &entries,
.maps = &rz_bin_maps_of_file_sections,
.sections = &sections,
.info = &info,
.header = &header,
.relocs = &relocs,
};
#ifndef RZ_PLUGIN_INCORE
RZ_API RzLibStruct rizin_plugin = {
.type = RZ_LIB_TYPE_BIN,
.data = &rz_bin_plugin_mz,
.version = RZ_VERSION
};
#endif