X-Git-Url: https://git.sven.stormbind.net/?p=sven%2Fexfatprogs.git;a=blobdiff_plain;f=mkfs%2Fmkfs.c;h=b5b4957c72158bf844c2b69a4d4bb9a2b448d01c;hp=18376692791b60acd584f05f0f84ad428cf7451e;hb=dcb4e80c267579d1a68e3f34f6b750e2940dbcc2;hpb=37cbd64649f64ddb88b4ab3d8a494ddf96890cf8

diff --git a/mkfs/mkfs.c b/mkfs/mkfs.c
index 1837669..b5b4957 100644
--- a/mkfs/mkfs.c
+++ b/mkfs/mkfs.c
@@ -46,14 +46,14 @@ static void exfat_setup_boot_sector(struct pbr *ppbr,
 	struct bsx64 *pbsx = &ppbr->bsx;
 	unsigned int i;
 
-	/* Fill exfat BIOS paramemter block */
+	/* Fill exfat BIOS parameter block */
 	pbpb->jmp_boot[0] = 0xeb;
 	pbpb->jmp_boot[1] = 0x76;
 	pbpb->jmp_boot[2] = 0x90;
 	memcpy(pbpb->oem_name, "EXFAT   ", 8);
 	memset(pbpb->res_zero, 0, 53);
 
-	/* Fill exfat extend BIOS paramemter block */
+	/* Fill exfat extend BIOS parameter block */
 	pbsx->vol_offset = cpu_to_le64(bd->offset / bd->sector_size);
 	pbsx->vol_length = cpu_to_le64(bd->size / bd->sector_size);
 	pbsx->fat_offset = cpu_to_le32(finfo.fat_byte_off / bd->sector_size);
@@ -72,6 +72,7 @@ static void exfat_setup_boot_sector(struct pbr *ppbr,
 	/* fs_version[0] : minor and fs_version[1] : major */
 	pbsx->fs_version[0] = 0;
 	pbsx->fs_version[1] = 1;
+	pbsx->phy_drv_no = 0x80;
 	memset(pbsx->reserved2, 0, 7);
 
 	memset(ppbr->boot_code, 0, 390);
@@ -109,12 +110,12 @@ static int exfat_write_boot_sector(struct exfat_blk_dev *bd,
 	if (is_backup)
 		sec_idx += BACKUP_BOOT_SEC_IDX;
 
-	ppbr = malloc(sizeof(struct pbr));
+	ppbr = malloc(bd->sector_size);
 	if (!ppbr) {
 		exfat_err("Cannot allocate pbr: out of memory\n");
 		return -1;
 	}
-	memset(ppbr, 0, sizeof(struct pbr));
+	memset(ppbr, 0, bd->sector_size);
 
 	exfat_setup_boot_sector(ppbr, bd, ui);
 
@@ -126,7 +127,7 @@ static int exfat_write_boot_sector(struct exfat_blk_dev *bd,
 		goto free_ppbr;
 	}
 
-	boot_calc_checksum((unsigned char *)ppbr, sizeof(struct pbr),
+	boot_calc_checksum((unsigned char *)ppbr, bd->sector_size,
 		true, checksum);
 
 free_ppbr:
@@ -137,26 +138,36 @@ free_ppbr:
 static int exfat_write_extended_boot_sectors(struct exfat_blk_dev *bd,
 		unsigned int *checksum, bool is_backup)
 {
-	struct exbs eb;
+	char *peb;
+	__le16 *peb_signature;
+	int ret = 0;
 	int i;
 	unsigned int sec_idx = EXBOOT_SEC_IDX;
 
+	peb = malloc(bd->sector_size);
+	if (!peb)
+		return -1;
+
 	if (is_backup)
 		sec_idx += BACKUP_BOOT_SEC_IDX;
 
-	memset(&eb, 0, sizeof(struct exbs));
-	eb.signature = cpu_to_le16(PBR_SIGNATURE);
+	memset(peb, 0, bd->sector_size);
+	peb_signature = (__le16*) (peb + bd->sector_size - 2);
+	*peb_signature = cpu_to_le16(PBR_SIGNATURE);
 	for (i = 0; i < EXBOOT_SEC_NUM; i++) {
-		if (exfat_write_sector(bd, &eb, sec_idx++)) {
+		if (exfat_write_sector(bd, peb, sec_idx++)) {
 			exfat_err("extended boot sector write failed\n");
-			return -1;
+			ret = -1;
+			goto free_peb;
 		}
 
-		boot_calc_checksum((unsigned char *) &eb, sizeof(struct exbs),
+		boot_calc_checksum((unsigned char *) peb, bd->sector_size,
 			false, checksum);
 	}
 
-	return 0;
+free_peb:
+	free(peb);
+	return ret;
 }
 
 static int exfat_write_oem_sector(struct exfat_blk_dev *bd,
@@ -224,9 +235,9 @@ static int write_fat_entry(int fd, __le32 clu,
 		unsigned long long offset)
 {
 	int nbyte;
+	off_t fat_entry_offset = finfo.fat_byte_off + (offset * sizeof(__le32));
 
-	lseek(fd, finfo.fat_byte_off + (offset * sizeof(__le32)), SEEK_SET);
-	nbyte = write(fd, (__u8 *) &clu, sizeof(__le32));
+	nbyte = pwrite(fd, (__u8 *) &clu, sizeof(__le32), fat_entry_offset);
 	if (nbyte != sizeof(int)) {
 		exfat_err("write failed, offset : %llu, clu : %x\n",
 			offset, clu);
@@ -310,8 +321,7 @@ static int exfat_create_bitmap(struct exfat_blk_dev *bd)
 	for (i = 0; i < finfo.used_clu_cnt - EXFAT_FIRST_CLUSTER; i++)
 		exfat_set_bit(bd, bitmap, i);
 
-	lseek(bd->dev_fd, finfo.bitmap_byte_off, SEEK_SET);
-	nbytes = write(bd->dev_fd, bitmap, finfo.bitmap_byte_len);
+	nbytes = pwrite(bd->dev_fd, bitmap, finfo.bitmap_byte_len, finfo.bitmap_byte_off);
 	if (nbytes != finfo.bitmap_byte_len) {
 		exfat_err("write failed, nbytes : %d, bitmap_len : %d\n",
 			nbytes, finfo.bitmap_byte_len);
@@ -348,8 +358,7 @@ static int exfat_create_root_dir(struct exfat_blk_dev *bd,
 	ed[2].upcase_start_clu = cpu_to_le32(finfo.ut_start_clu);
 	ed[2].upcase_size = cpu_to_le64(EXFAT_UPCASE_TABLE_SIZE);
 
-	lseek(bd->dev_fd, finfo.root_byte_off, SEEK_SET);
-	nbytes = write(bd->dev_fd, ed, dentries_len);
+	nbytes = pwrite(bd->dev_fd, ed, dentries_len, finfo.root_byte_off);
 	if (nbytes != dentries_len) {
 		exfat_err("write failed, nbytes : %d, dentries_len : %d\n",
 			nbytes, dentries_len);
@@ -429,6 +438,11 @@ static int exfat_build_mkfs_info(struct exfat_blk_dev *bd,
 	unsigned long long total_clu_cnt;
 	int clu_len;
 
+	if (ui->cluster_size < bd->sector_size) {
+		exfat_err("cluster size (%u bytes) is smaller than sector size (%u bytes)\n",
+			  ui->cluster_size, bd->sector_size);
+		return -1;
+	}
 	if (ui->boundary_align < bd->sector_size) {
 		exfat_err("boundary alignment is too small (min %d)\n",
 				bd->sector_size);
@@ -436,8 +450,12 @@ static int exfat_build_mkfs_info(struct exfat_blk_dev *bd,
 	}
 	finfo.fat_byte_off = round_up(bd->offset + 24 * bd->sector_size,
 			ui->boundary_align) - bd->offset;
-	finfo.fat_byte_len = round_up((bd->num_clusters * sizeof(int)),
-		ui->cluster_size);
+	/* Prevent integer overflow when computing the FAT length */
+	if (bd->num_clusters > UINT32_MAX / 4) {
+		exfat_err("cluster size (%u bytes) is too small\n", ui->cluster_size);
+		return -1;
+	}
+	finfo.fat_byte_len = round_up((bd->num_clusters * 4), ui->cluster_size);
 	finfo.clu_byte_off = round_up(bd->offset + finfo.fat_byte_off +
 		finfo.fat_byte_len, ui->boundary_align) - bd->offset;
 	if (bd->size <= finfo.clu_byte_off) {