Do not try to load LUKS2 header if backup_file is LUKS1.

Also do not allow header restore if a different version is requested.

lib/internal.h

@@ -103,7 +103,7 @@ void device_disable_direct_io(struct device *device);
 int device_is_identical(struct device *device1, struct device *device2);
 int device_is_rotational(struct device *device);
 size_t device_alignment(struct device *device);
-int device_direct_io(struct device *device);
+int device_direct_io(const struct device *device);
 
 int device_open_locked(struct device *device, int flags);
 int device_read_lock(struct crypt_device *cd, struct device *device);

lib/luks2/luks2.h

@@ -109,7 +109,8 @@ struct luks2_hdr {
 
 #define LUKS2_MAX_KEYSLOTS_SIZE 0x8000000 /* 128 MiB */
 
-int LUKS2_hdr_version_unlocked(struct crypt_device *cd);
+int LUKS2_hdr_version_unlocked(struct crypt_device *cd,
+	const char *backup_file);
 
 int LUKS2_hdr_read(struct crypt_device *cd, struct luks2_hdr *hdr);
 int LUKS2_hdr_write(struct crypt_device *cd, struct luks2_hdr *hdr);

lib/luks2/luks2_disk_metadata.c

@@ -666,14 +666,19 @@ err:
 	return r;
 }
 
-int LUKS2_hdr_version_unlocked(struct crypt_device *cd)
+int LUKS2_hdr_version_unlocked(struct crypt_device *cd, const char *backup_file)
 {
 	struct {
 		char magic[LUKS2_MAGIC_L];
 		uint16_t version;
 	}  __attribute__ ((packed)) hdr;
-	struct device *device = crypt_metadata_device(cd);
-	int r, devfd, flags;
+	struct device *device = NULL;
+	int r = 0, devfd = -1, flags;
+
+	if (!backup_file)
+		device = crypt_metadata_device(cd);
+	else if (device_alloc(&device, backup_file) < 0)
+		return 0;
 
 	if (!device)
 		return 0;
@@ -684,16 +689,18 @@ int LUKS2_hdr_version_unlocked(struct crypt_device *cd)
 
 	devfd = open(device_path(device), flags);
 	if (devfd < 0)
-		return 0;
+		goto err;
 
 	if ((read_lseek_blockwise(devfd, device_block_size(device),
-				  device_alignment(device), &hdr, sizeof(hdr), 0)
-				  != sizeof(hdr)) ||
-				  memcmp(hdr.magic, LUKS2_MAGIC_1ST, LUKS2_MAGIC_L))
-		r = 0;
-	else
+	     device_alignment(device), &hdr, sizeof(hdr), 0) == sizeof(hdr)) &&
+	    !memcmp(hdr.magic, LUKS2_MAGIC_1ST, LUKS2_MAGIC_L))
 		r = (int)be16_to_cpu(hdr.version);
-
+err:
+	if (devfd != -1)
 		close(devfd);
+
+	if (backup_file)
+		device_free(device);
+
 	return r;
 }

lib/setup.c

@@ -724,7 +724,7 @@ static int _crypt_load_luks(struct crypt_device *cd, const char *requested_type,
 
 	/* This will return 0 if primary LUKS2 header is damaged */
 	if (!requested_type)
-		version = LUKS2_hdr_version_unlocked(cd);
+		version = LUKS2_hdr_version_unlocked(cd, NULL);
 
 	if (isLUKS1(requested_type) || version == 1) {
 		if (cd->type && isLUKS2(cd->type)) {
@@ -2162,7 +2162,7 @@ int crypt_header_restore(struct crypt_device *cd,
 {
 	struct luks_phdr hdr1;
 	struct luks2_hdr hdr2;
-	int r;
+	int r, version;
 
 	if (requested_type && !isLUKS(requested_type))
 		return -EINVAL;
@@ -2177,15 +2177,21 @@ int crypt_header_restore(struct crypt_device *cd,
 	log_dbg("Requested header restore to device %s (%s) from "
 		"file %s.", mdata_device_path(cd), requested_type ?: "any type", backup_file);
 
-	memset(&hdr2, 0, sizeof(hdr2));
-	if (!cd->type) {
-		if (!requested_type || isLUKS2(requested_type))
-			r = LUKS2_hdr_restore(cd, &hdr2, backup_file);
-		else
-			r = -ENOENT;
+	version = LUKS2_hdr_version_unlocked(cd, backup_file);
+	if (!version ||
+	   (requested_type && version == 1 && !isLUKS1(requested_type)) ||
+	   (requested_type && version == 2 && !isLUKS2(requested_type))) {
+		log_err(cd, _("Header backup file does not contain compatible LUKS header.\n"));
+		return -EINVAL;
+	}
 
-		if (r && (!requested_type || isLUKS1(requested_type)))
+	memset(&hdr2, 0, sizeof(hdr2));
+
+	if (!cd->type) {
+		if (version == 1)
 			r = LUKS_hdr_restore(backup_file, &hdr1, cd);
+		else
+			r = LUKS2_hdr_restore(cd, &hdr2, backup_file);
 
 		LUKS2_hdr_free(&hdr2);
 		crypt_memzero(&hdr1, sizeof(hdr1));

lib/utils_device.c

@@ -693,7 +693,7 @@ void device_disable_direct_io(struct device *device)
 	device->o_direct = 0;
 }
 
-int device_direct_io(struct device *device)
+int device_direct_io(const struct device *device)
 {
 	return device->o_direct;
 }