668 lines
24 KiB
C
668 lines
24 KiB
C
/*
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* Copyright (C) 2014-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
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*
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* Authors: Kevin Lin <klin@sourcefire.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*/
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#if HAVE_CONFIG_H
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#include "clamav-config.h"
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#endif
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#include <stdio.h>
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#include <errno.h>
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#if HAVE_STRING_H
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#include <string.h>
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#endif
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#include <ctype.h>
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#include <fcntl.h>
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#include <zlib.h>
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#include "clamav.h"
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#include "others.h"
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#include "gpt.h"
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#include "mbr.h"
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#include "str.h"
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#include "entconv.h"
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#include "partition_intersection.h"
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#include "scanners.h"
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#include "dconf.h"
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//#define DEBUG_GPT_PARSE
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//#define DEBUG_GPT_PRINT
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#ifdef DEBUG_GPT_PARSE
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#define gpt_parsemsg(...) cli_dbgmsg(__VA_ARGS__)
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#else
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#define gpt_parsemsg(...) ;
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#endif
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#ifdef DEBUG_GPT_PRINT
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#define gpt_printmsg(...) cli_dbgmsg(__VA_ARGS__)
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#else
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#define gpt_printmsg(...) ;
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#endif
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enum GPT_SCANSTATE {
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INVALID,
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PRIMARY_ONLY,
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SECONDARY_ONLY,
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BOTH
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};
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static cl_error_t gpt_scan_partitions(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize);
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static cl_error_t gpt_validate_header(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize);
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static cl_error_t gpt_check_mbr(cli_ctx *ctx, size_t sectorsize);
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static void gpt_printSectors(cli_ctx *ctx, size_t sectorsize);
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static void gpt_printGUID(uint8_t GUID[], const char *msg);
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static cl_error_t gpt_partition_intersection(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize);
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/* returns 0 on failing to detect sectorsize */
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size_t gpt_detect_size(fmap_t *map)
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{
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unsigned char *buff;
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buff = (unsigned char *)fmap_need_off_once(map, 512, 8);
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if (!buff) return 0;
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if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
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return 512;
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buff = (unsigned char *)fmap_need_off_once(map, 1024, 8);
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if (!buff) return 0;
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if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
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return 1024;
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buff = (unsigned char *)fmap_need_off_once(map, 2048, 8);
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if (!buff) return 0;
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if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
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return 2048;
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buff = (unsigned char *)fmap_need_off_once(map, 4096, 8);
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if (!buff) return 0;
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if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
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return 4096;
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return 0;
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}
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/* attempts to detect sector size is input as 0 */
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cl_error_t cli_scangpt(cli_ctx *ctx, size_t sectorsize)
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{
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cl_error_t status = CL_SUCCESS;
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struct gpt_header phdr, shdr;
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enum GPT_SCANSTATE state = INVALID;
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size_t maplen;
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off_t pos = 0;
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gpt_parsemsg("The beginning of something big: GPT parsing\n");
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if (!ctx || !ctx->fmap) {
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cli_errmsg("cli_scangpt: Invalid context\n");
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status = CL_ENULLARG;
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goto done;
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}
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/* sector size calculation */
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if (sectorsize == 0) {
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sectorsize = gpt_detect_size(ctx->fmap);
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cli_dbgmsg("cli_scangpt: detected %lu sector size\n", (unsigned long)sectorsize);
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}
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if (sectorsize == 0) {
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cli_dbgmsg("cli_scangpt: could not determine sector size\n");
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status = CL_EFORMAT;
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goto done;
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}
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/* size of total file must be a multiple of the sector size */
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maplen = ctx->fmap->len;
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if ((maplen % sectorsize) != 0) {
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cli_dbgmsg("cli_scangpt: File sized %lu is not a multiple of sector size %lu\n",
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(unsigned long)maplen, (unsigned long)sectorsize);
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status = CL_EFORMAT;
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goto done;
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}
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/* check the protective mbr */
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status = gpt_check_mbr(ctx, sectorsize);
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if (status != CL_SUCCESS) {
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goto done;
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}
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pos = GPT_PRIMARY_HDR_LBA * sectorsize; /* sector 1 (second sector) is the primary gpt header */
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/* read primary gpt header */
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cli_dbgmsg("cli_scangpt: Using primary GPT header\n");
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if (fmap_readn(ctx->fmap, &phdr, pos, sizeof(phdr)) != sizeof(phdr)) {
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cli_dbgmsg("cli_scangpt: Invalid primary GPT header\n");
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status = CL_EFORMAT;
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goto done;
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}
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pos = maplen - sectorsize; /* last sector is the secondary gpt header */
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if (gpt_validate_header(ctx, phdr, sectorsize)) {
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cli_dbgmsg("cli_scangpt: Primary GPT header is invalid\n");
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cli_dbgmsg("cli_scangpt: Using secondary GPT header\n");
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state = SECONDARY_ONLY;
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/* read secondary gpt header */
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if (fmap_readn(ctx->fmap, &shdr, pos, sizeof(shdr)) != sizeof(shdr)) {
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cli_dbgmsg("cli_scangpt: Invalid secondary GPT header\n");
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status = CL_EFORMAT;
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goto done;
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}
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if (gpt_validate_header(ctx, shdr, sectorsize)) {
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cli_dbgmsg("cli_scangpt: Secondary GPT header is invalid\n");
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cli_dbgmsg("cli_scangpt: Disk is unusable\n");
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status = CL_EFORMAT;
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goto done;
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}
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} else {
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cli_dbgmsg("cli_scangpt: Checking secondary GPT header\n");
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state = PRIMARY_ONLY;
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/* check validity of secondary header; still using the primary */
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if (fmap_readn(ctx->fmap, &shdr, pos, sizeof(shdr)) != sizeof(shdr)) {
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cli_dbgmsg("cli_scangpt: Invalid secondary GPT header\n");
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} else if (gpt_validate_header(ctx, shdr, sectorsize)) {
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cli_dbgmsg("cli_scangpt: Secondary GPT header is invalid\n");
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}
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/* check that the two partition table crc32 checksum match,
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* may want a different hashing function */
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else if (phdr.tableCRC32 != shdr.tableCRC32) {
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cli_dbgmsg("cli_scangpt: Primary and secondary GPT header table CRC32 differ\n");
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cli_dbgmsg("cli_scangpt: Set to scan primary and secondary partition tables\n");
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state = BOTH;
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} else {
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cli_dbgmsg("cli_scangpt: Secondary GPT header check OK\n");
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}
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}
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/* check that the partition table has no intersections - HEURISTICS */
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if (SCAN_HEURISTIC_PARTITION_INTXN && (ctx->dconf->other & OTHER_CONF_PRTNINTXN)) {
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status = gpt_partition_intersection(ctx, phdr, sectorsize);
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if (status != CL_SUCCESS) {
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goto done;
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}
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status = gpt_partition_intersection(ctx, shdr, sectorsize);
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if (status != CL_SUCCESS) {
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goto done;
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}
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}
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/* scanning partitions */
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switch (state) {
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case PRIMARY_ONLY:
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cli_dbgmsg("cli_scangpt: Scanning primary GPT partitions only\n");
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status = gpt_scan_partitions(ctx, phdr, sectorsize);
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if (status != CL_SUCCESS) {
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goto done;
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}
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break;
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case SECONDARY_ONLY:
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cli_dbgmsg("cli_scangpt: Scanning secondary GPT partitions only\n");
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status = gpt_scan_partitions(ctx, shdr, sectorsize);
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if (status != CL_SUCCESS) {
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goto done;
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}
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break;
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case BOTH:
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cli_dbgmsg("cli_scangpt: Scanning primary GPT partitions\n");
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status = gpt_scan_partitions(ctx, phdr, sectorsize);
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if (status != CL_SUCCESS) {
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goto done;
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}
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cli_dbgmsg("cli_scangpt: Scanning secondary GPT partitions\n");
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status = gpt_scan_partitions(ctx, shdr, sectorsize);
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if (status != CL_SUCCESS) {
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goto done;
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}
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break;
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default:
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cli_dbgmsg("cli_scangpt: State is invalid\n");
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}
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status = CL_SUCCESS;
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done:
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return status;
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}
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static cl_error_t gpt_scan_partitions(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize)
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{
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cl_error_t status = CL_SUCCESS;
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struct gpt_partition_entry gpe;
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size_t maplen, part_size = 0;
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size_t pos = 0, part_off = 0;
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unsigned i = 0, j = 0;
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uint32_t max_prtns = 0;
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char *namestr = NULL;
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/* convert endian to host */
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hdr.signature = be64_to_host(hdr.signature);
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hdr.revision = be32_to_host(hdr.revision);
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hdr.headerSize = le32_to_host(hdr.headerSize);
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hdr.headerCRC32 = le32_to_host(hdr.headerCRC32);
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hdr.reserved = le32_to_host(hdr.reserved);
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hdr.currentLBA = le64_to_host(hdr.currentLBA);
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hdr.backupLBA = le64_to_host(hdr.backupLBA);
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hdr.firstUsableLBA = le64_to_host(hdr.firstUsableLBA);
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hdr.lastUsableLBA = le64_to_host(hdr.lastUsableLBA);
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hdr.tableStartLBA = le64_to_host(hdr.tableStartLBA);
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hdr.tableNumEntries = le32_to_host(hdr.tableNumEntries);
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hdr.tableEntrySize = le32_to_host(hdr.tableEntrySize);
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hdr.tableCRC32 = le32_to_host(hdr.tableCRC32);
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/* print header info for the debug */
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cli_dbgmsg("GPT Header:\n");
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cli_dbgmsg("Signature: 0x%llx\n", (long long unsigned)hdr.signature);
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cli_dbgmsg("Revision: %x\n", hdr.revision);
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gpt_printGUID(hdr.DiskGUID, "DISK GUID");
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cli_dbgmsg("Partition Entry Count: %u\n", hdr.tableNumEntries);
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cli_dbgmsg("Partition Entry Size: %u\n", hdr.tableEntrySize);
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maplen = ctx->fmap->len;
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/* check engine maxpartitions limit */
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if (hdr.tableNumEntries < ctx->engine->maxpartitions) {
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max_prtns = hdr.tableNumEntries;
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} else {
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max_prtns = ctx->engine->maxpartitions;
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}
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/* use the partition tables to pass partitions to cli_magic_scan_nested_fmap_type */
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pos = hdr.tableStartLBA * sectorsize;
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for (i = 0; i < max_prtns; ++i) {
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/* read in partition entry */
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if (fmap_readn(ctx->fmap, &gpe, pos, sizeof(gpe)) != sizeof(gpe)) {
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cli_dbgmsg("cli_scangpt: Invalid GPT partition entry\n");
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status = CL_EFORMAT;
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goto done;
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}
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/* convert the endian to host */
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gpe.firstLBA = le64_to_host(gpe.firstLBA);
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gpe.lastLBA = le64_to_host(gpe.lastLBA);
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gpe.attributes = le64_to_host(gpe.attributes);
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for (j = 0; j < 36; ++j) {
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gpe.name[i] = le16_to_host(gpe.name[i]);
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}
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/* check that partition is not empty and within a valid location */
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if (gpe.firstLBA == 0) {
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/* empty partition, invalid */
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} else if ((gpe.firstLBA > gpe.lastLBA) ||
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(gpe.firstLBA < hdr.firstUsableLBA) || (gpe.lastLBA > hdr.lastUsableLBA)) {
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cli_dbgmsg("cli_scangpt: GPT partition exists outside specified bounds\n");
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gpt_parsemsg("%llu < %llu, %llu > %llu\n", gpe.firstLBA, hdr.firstUsableLBA,
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gpe.lastLBA, hdr.lastUsableLBA);
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/* partition exists outside bounds specified by header or invalid */
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} else if (((gpe.lastLBA + 1) * sectorsize) > maplen) {
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/* partition exists outside bounds of the file map */
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} else {
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namestr = (char *)cli_utf16toascii((char *)gpe.name, 72);
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// It's okay if namestr is NULL.
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/* print partition entry data for debug */
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cli_dbgmsg("GPT Partition Entry %u:\n", i);
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cli_dbgmsg("Name: %s\n", namestr);
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gpt_printGUID(gpe.typeGUID, "Type GUID");
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gpt_printGUID(gpe.uniqueGUID, "Unique GUID");
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cli_dbgmsg("Attributes: %llx\n", (long long unsigned)gpe.attributes);
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cli_dbgmsg("Blocks: [%llu(%llu) -> %llu(%llu)]\n",
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(long long unsigned)gpe.firstLBA, (long long unsigned)(gpe.firstLBA * sectorsize),
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(long long unsigned)gpe.lastLBA, (long long unsigned)((gpe.lastLBA + 1) * sectorsize));
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/* send the partition to cli_magic_scan_nested_fmap_type */
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part_off = gpe.firstLBA * sectorsize;
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part_size = (gpe.lastLBA - gpe.firstLBA + 1) * sectorsize;
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status = cli_magic_scan_nested_fmap_type(ctx->fmap, part_off, part_size, ctx, CL_TYPE_PART_ANY, namestr, LAYER_ATTRIBUTES_NONE);
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if (status != CL_SUCCESS) {
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goto done;
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}
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if (NULL != namestr) {
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free(namestr);
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namestr = NULL;
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}
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}
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/* increment the offsets to next partition entry */
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pos += hdr.tableEntrySize;
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}
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if (i >= ctx->engine->maxpartitions) {
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cli_dbgmsg("cli_scangpt: max partitions reached\n");
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}
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done:
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if (NULL != namestr) {
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free(namestr);
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}
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return status;
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}
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static cl_error_t gpt_validate_header(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize)
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{
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cl_error_t status = CL_SUCCESS;
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uint32_t crc32_calc, crc32_ref;
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uint64_t tableLastLBA, lastLBA;
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size_t maplen, ptable_start, ptable_len;
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unsigned char *ptable;
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maplen = ctx->fmap->len;
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/* checking header crc32 checksum */
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crc32_ref = le32_to_host(hdr.headerCRC32);
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hdr.headerCRC32 = 0; /* checksum is calculated with field = 0 */
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crc32_calc = crc32(0, (unsigned char *)&hdr, sizeof(hdr));
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if (crc32_calc != crc32_ref) {
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cli_dbgmsg("cli_scangpt: GPT header checksum mismatch\n");
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gpt_parsemsg("%x != %x\n", crc32_calc, crc32_ref);
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status = CL_EFORMAT;
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goto done;
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}
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/* convert endian to host to check partition table */
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hdr.signature = be64_to_host(hdr.signature);
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hdr.revision = be32_to_host(hdr.revision);
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hdr.headerSize = le32_to_host(hdr.headerSize);
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hdr.headerCRC32 = crc32_ref;
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hdr.reserved = le32_to_host(hdr.reserved);
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hdr.currentLBA = le64_to_host(hdr.currentLBA);
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hdr.backupLBA = le64_to_host(hdr.backupLBA);
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hdr.firstUsableLBA = le64_to_host(hdr.firstUsableLBA);
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hdr.lastUsableLBA = le64_to_host(hdr.lastUsableLBA);
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hdr.tableStartLBA = le64_to_host(hdr.tableStartLBA);
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hdr.tableNumEntries = le32_to_host(hdr.tableNumEntries);
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hdr.tableEntrySize = le32_to_host(hdr.tableEntrySize);
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hdr.tableCRC32 = le32_to_host(hdr.tableCRC32);
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ptable_start = hdr.tableStartLBA * sectorsize;
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ptable_len = hdr.tableNumEntries * hdr.tableEntrySize;
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tableLastLBA = (hdr.tableStartLBA + (ptable_len / sectorsize)) - 1;
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lastLBA = (maplen / sectorsize) - 1;
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/** HEADER CHECKS **/
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gpt_printSectors(ctx, sectorsize);
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/* check signature */
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if (hdr.signature != GPT_SIGNATURE) {
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cli_dbgmsg("cli_scangpt: Invalid GPT header signature %llx\n",
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(long long unsigned)hdr.signature);
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status = CL_EFORMAT;
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goto done;
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}
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/* check header size */
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if (hdr.headerSize != sizeof(hdr)) {
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cli_dbgmsg("cli_scangpt: GPT header size does not match stated size\n");
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status = CL_EFORMAT;
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goto done;
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}
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/* check reserved value == 0 */
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if (hdr.reserved != GPT_HDR_RESERVED) {
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cli_dbgmsg("cli_scangpt: GPT header reserved is not expected value\n");
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status = CL_EFORMAT;
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goto done;
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}
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/* check that sectors are in a valid configuration */
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if (!((hdr.currentLBA == GPT_PRIMARY_HDR_LBA && hdr.backupLBA == lastLBA) ||
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(hdr.currentLBA == lastLBA && hdr.backupLBA == GPT_PRIMARY_HDR_LBA))) {
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cli_dbgmsg("cli_scangpt: GPT secondary header is not last LBA\n");
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status = CL_EFORMAT;
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goto done;
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}
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if (hdr.firstUsableLBA > hdr.lastUsableLBA) {
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cli_dbgmsg("cli_scangpt: GPT first usable sectors is after last usable sector\n");
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status = CL_EFORMAT;
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goto done;
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}
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if (hdr.firstUsableLBA <= GPT_PRIMARY_HDR_LBA || hdr.lastUsableLBA >= lastLBA) {
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cli_dbgmsg("cli_scangpt: GPT usable sectors intersects header sector\n");
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status = CL_EFORMAT;
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goto done;
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}
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if ((hdr.tableStartLBA <= hdr.firstUsableLBA && tableLastLBA >= hdr.firstUsableLBA) ||
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(hdr.tableStartLBA >= hdr.firstUsableLBA && hdr.tableStartLBA <= hdr.lastUsableLBA)) {
|
|
cli_dbgmsg("cli_scangpt: GPT usable sectors intersects partition table\n");
|
|
status = CL_EFORMAT;
|
|
goto done;
|
|
}
|
|
if (hdr.tableStartLBA <= GPT_PRIMARY_HDR_LBA || tableLastLBA >= lastLBA) {
|
|
cli_dbgmsg("cli_scangpt: GPT partition table intersects header sector\n");
|
|
status = CL_EFORMAT;
|
|
goto done;
|
|
}
|
|
|
|
/* check that valid table entry size */
|
|
if (hdr.tableEntrySize != sizeof(struct gpt_partition_entry)) {
|
|
cli_dbgmsg("cli_scangpt: cannot parse gpt with partition entry sized %u\n",
|
|
hdr.tableEntrySize);
|
|
status = CL_EFORMAT;
|
|
goto done;
|
|
}
|
|
|
|
/* check valid table */
|
|
if ((ptable_start + ptable_len) > maplen) {
|
|
cli_dbgmsg("cli_scangpt: GPT partition table extends over fmap limit\n");
|
|
status = CL_EFORMAT;
|
|
goto done;
|
|
}
|
|
|
|
/** END HEADER CHECKS **/
|
|
|
|
/* checking partition table crc32 checksum */
|
|
ptable = (unsigned char *)fmap_need_off_once(ctx->fmap, ptable_start, ptable_len);
|
|
crc32_calc = crc32(0, ptable, ptable_len);
|
|
if (crc32_calc != hdr.tableCRC32) {
|
|
cli_dbgmsg("cli_scangpt: GPT partition table checksum mismatch\n");
|
|
gpt_parsemsg("%x != %x\n", crc32_calc, hdr.tableCRC32);
|
|
status = CL_EFORMAT;
|
|
goto done;
|
|
}
|
|
|
|
done:
|
|
|
|
return status;
|
|
}
|
|
|
|
static cl_error_t gpt_check_mbr(cli_ctx *ctx, size_t sectorsize)
|
|
{
|
|
cl_error_t status = CL_SUCCESS;
|
|
struct mbr_boot_record pmbr;
|
|
size_t pos = 0, mbr_base = 0;
|
|
unsigned i = 0;
|
|
|
|
/* read the mbr */
|
|
mbr_base = sectorsize - sizeof(struct mbr_boot_record);
|
|
pos = (MBR_SECTOR * sectorsize) + mbr_base;
|
|
|
|
if (fmap_readn(ctx->fmap, &pmbr, pos, sizeof(pmbr)) != sizeof(pmbr)) {
|
|
cli_dbgmsg("cli_scangpt: Invalid primary MBR header\n");
|
|
status = CL_EFORMAT;
|
|
goto done;
|
|
}
|
|
|
|
/* convert mbr */
|
|
mbr_convert_to_host(&pmbr);
|
|
|
|
/* check the protective mbr - warning */
|
|
if (pmbr.entries[0].type == MBR_PROTECTIVE) {
|
|
/* check the efi partition matches the gpt spec */
|
|
if (pmbr.entries[0].firstLBA != GPT_PRIMARY_HDR_LBA) {
|
|
cli_warnmsg("cli_scangpt: protective MBR first LBA is incorrect %u\n",
|
|
pmbr.entries[0].firstLBA);
|
|
}
|
|
|
|
/* other entries are empty */
|
|
for (i = 1; i < MBR_MAX_PARTITION_ENTRIES; ++i) {
|
|
if (pmbr.entries[i].type != MBR_EMPTY) {
|
|
cli_warnmsg("cli_scangpt: protective MBR has non-empty partition\n");
|
|
break;
|
|
}
|
|
}
|
|
} else if (pmbr.entries[0].type == MBR_HYBRID) {
|
|
/* hybrid mbr detected */
|
|
cli_warnmsg("cli_scangpt: detected a hybrid MBR\n");
|
|
} else {
|
|
/* non-protective mbr detected */
|
|
cli_warnmsg("cli_scangpt: detected a non-protective MBR\n");
|
|
}
|
|
|
|
/* scan the bootloader segment - pushed to scanning mbr */
|
|
/* check if MBR size matches GPT size */
|
|
/* check if the MBR and GPT partitions align - heuristic */
|
|
/* scan the MBR partitions - additional scans */
|
|
|
|
done:
|
|
|
|
return status;
|
|
}
|
|
|
|
static void gpt_printSectors(cli_ctx *ctx, size_t sectorsize)
|
|
{
|
|
#ifdef DEBUG_GPT_PARSE
|
|
struct gpt_header phdr, shdr;
|
|
size_t ppos = 0, spos = 0;
|
|
size_t pptable_len, sptable_len, maplen;
|
|
uint64_t ptableLastLBA, stableLastLBA;
|
|
|
|
/* sector size calculation */
|
|
sectorsize = GPT_DEFAULT_SECTOR_SIZE;
|
|
|
|
maplen = ctx->fmap->len;
|
|
|
|
ppos = 1 * sectorsize; /* sector 1 (second sector) is the primary gpt header */
|
|
spos = maplen - sectorsize; /* last sector is the secondary gpt header */
|
|
|
|
/* read in the primary and secondary gpt headers */
|
|
if (fmap_readn(ctx->fmap, &phdr, ppos, sizeof(phdr)) != sizeof(phdr)) {
|
|
cli_dbgmsg("cli_scangpt: Invalid primary GPT header\n");
|
|
return;
|
|
}
|
|
if (fmap_readn(ctx->fmap, &shdr, spos, sizeof(shdr)) != sizeof(shdr)) {
|
|
cli_dbgmsg("cli_scangpt: Invalid secondary GPT header\n");
|
|
return;
|
|
}
|
|
|
|
pptable_len = phdr.tableNumEntries * phdr.tableEntrySize;
|
|
sptable_len = shdr.tableNumEntries * shdr.tableEntrySize;
|
|
ptableLastLBA = (phdr.tableStartLBA + (pptable_len / sectorsize)) - 1;
|
|
stableLastLBA = (shdr.tableStartLBA + (sptable_len / sectorsize)) - 1;
|
|
|
|
gpt_parsemsg("0: MBR\n");
|
|
gpt_parsemsg("%llu: Primary GPT Header\n", phdr.currentLBA);
|
|
gpt_parsemsg("%llu-%llu: Primary GPT Partition Table\n", phdr.tableStartLBA, ptableLastLBA);
|
|
gpt_parsemsg("%llu-%llu: Usable LBAs\n", phdr.firstUsableLBA, phdr.lastUsableLBA);
|
|
gpt_parsemsg("%llu-%llu: Secondary GPT Partition Table\n", shdr.tableStartLBA, stableLastLBA);
|
|
gpt_parsemsg("%llu: Secondary GPT Header\n", phdr.backupLBA);
|
|
#else
|
|
UNUSEDPARAM(ctx);
|
|
UNUSEDPARAM(sectorsize);
|
|
return;
|
|
#endif
|
|
}
|
|
|
|
static void gpt_printGUID(uint8_t GUID[], const char *msg)
|
|
{
|
|
cli_dbgmsg("%s: %02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n",
|
|
msg, GUID[0], GUID[1], GUID[2], GUID[3], GUID[4], GUID[5], GUID[6], GUID[7],
|
|
GUID[8], GUID[9], GUID[10], GUID[11], GUID[12], GUID[13], GUID[14], GUID[15]);
|
|
}
|
|
|
|
static cl_error_t gpt_partition_intersection(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize)
|
|
{
|
|
cl_error_t status = CL_SUCCESS;
|
|
cl_error_t ret;
|
|
partition_intersection_list_t prtncheck;
|
|
struct gpt_partition_entry gpe;
|
|
unsigned i, pitxn;
|
|
size_t pos;
|
|
size_t maplen;
|
|
uint32_t max_prtns = 0;
|
|
|
|
maplen = ctx->fmap->len;
|
|
|
|
/* convert endian to host to check partition table */
|
|
hdr.tableStartLBA = le64_to_host(hdr.tableStartLBA);
|
|
hdr.tableNumEntries = le32_to_host(hdr.tableNumEntries);
|
|
|
|
partition_intersection_list_init(&prtncheck);
|
|
|
|
/* check engine maxpartitions limit */
|
|
if (hdr.tableNumEntries < ctx->engine->maxpartitions) {
|
|
max_prtns = hdr.tableNumEntries;
|
|
} else {
|
|
max_prtns = ctx->engine->maxpartitions;
|
|
}
|
|
|
|
pos = hdr.tableStartLBA * sectorsize;
|
|
for (i = 0; i < max_prtns; ++i) {
|
|
/* read in partition entry */
|
|
if (fmap_readn(ctx->fmap, &gpe, pos, sizeof(gpe)) != sizeof(gpe)) {
|
|
cli_dbgmsg("cli_scangpt: Invalid GPT partition entry\n");
|
|
status = CL_EFORMAT;
|
|
goto done;
|
|
}
|
|
|
|
/* convert the endian to host */
|
|
gpe.firstLBA = le64_to_host(gpe.firstLBA);
|
|
gpe.lastLBA = le64_to_host(gpe.lastLBA);
|
|
|
|
if (gpe.firstLBA == 0) {
|
|
/* empty partition, invalid */
|
|
} else if ((gpe.firstLBA > gpe.lastLBA) ||
|
|
(gpe.firstLBA < hdr.firstUsableLBA) || (gpe.lastLBA > hdr.lastUsableLBA)) {
|
|
/* partition exists outside bounds specified by header or invalid */
|
|
} else if (((gpe.lastLBA + 1) * sectorsize) > maplen) {
|
|
/* partition exists outside bounds of the file map */
|
|
} else {
|
|
ret = partition_intersection_list_check(&prtncheck, &pitxn, gpe.firstLBA, gpe.lastLBA - gpe.firstLBA + 1);
|
|
if (ret != CL_SUCCESS) {
|
|
if (ret == CL_VIRUS) {
|
|
cli_dbgmsg("cli_scangpt: detected intersection with partitions "
|
|
"[%u, %u]\n",
|
|
pitxn, i);
|
|
status = cli_append_potentially_unwanted(ctx, "Heuristics.GPTPartitionIntersection");
|
|
if (status != CL_SUCCESS) {
|
|
goto done;
|
|
}
|
|
} else {
|
|
status = ret;
|
|
goto done;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* increment the offsets to next partition entry */
|
|
pos += hdr.tableEntrySize;
|
|
}
|
|
|
|
done:
|
|
|
|
partition_intersection_list_free(&prtncheck);
|
|
return status;
|
|
}
|