Detect broken LUKS metadata in-before encryption.

We should abort LUKS device in-place encryption
when target data device or metadata device
contain broken LUKS metadata (any version).
Filed crypt_load() call was not good enough check
because the call fails also when a device contains
LUKS metadata overlapping with other superblock
(e.g. LVM2 PV signature).

Let blkid decide if device contains broken LUKS
metadata or not.

Fixes: #723.

src/cryptsetup.h

@@ -112,7 +112,8 @@ int tools_write_json_file(const char *file, const char *json);
 
 typedef enum {
 	PRB_FILTER_NONE = 0,
-	PRB_FILTER_LUKS
+	PRB_FILTER_LUKS,
+	PRB_ONLY_LUKS
 } tools_probe_filter_info;
 
 int tools_detect_signatures(const char *device, tools_probe_filter_info filter, size_t *count, bool batch_mode);

src/utils_blockdev.c

@@ -220,12 +220,23 @@ int tools_detect_signatures(const char *device, tools_probe_filter_info filter,
 		return -EINVAL;
 	}
 
-	blk_set_chains_for_full_print(h);
-
-	if (filter == PRB_FILTER_LUKS && blk_superblocks_filter_luks(h)) {
+	switch (filter) {
+	case PRB_FILTER_LUKS:
+		if (blk_superblocks_filter_luks(h)) {
 			r = -EINVAL;
 			goto out;
 		}
+		/* fall-through */
+	case PRB_FILTER_NONE:
+		blk_set_chains_for_full_print(h);
+		break;
+	case PRB_ONLY_LUKS:
+		blk_set_chains_for_fast_detection(h);
+		if (blk_superblocks_only_luks(h)) {
+			r = -EINVAL;
+			goto out;
+		}
+	}
 
 	while ((pr = blk_probe(h)) < PRB_EMPTY) {
 		if (blk_is_partition(h))

src/utils_reencrypt.c

@@ -252,7 +252,6 @@ static enum device_status_info load_luks(struct crypt_device **r_cd, const char
 	if (crypt_init_data_device(&cd, uuid_or_device(header_device ?: data_device), data_device))
 		return DEVICE_INVALID;
 
-	/* TODO: LUKS2 load may fail when header is damaged and blkid reports ambiguous/other signatures */
 	if ((r = crypt_load(cd, CRYPT_LUKS, NULL))) {
 		crypt_free(cd);
 
@@ -924,10 +923,27 @@ static int reencrypt_luks2_resume(struct crypt_device *cd)
 	return r;
 }
 
+static int check_broken_luks_signature(const char *device)
+{
+	int r;
+	size_t count;
+
+	r = tools_detect_signatures(device, PRB_ONLY_LUKS, &count, ARG_SET(OPT_BATCH_MODE_ID));
+	if (r < 0)
+		return -EINVAL;
+	if (count) {
+		log_err(_("Device %s contains broken LUKS metadata. Aborting operation."), device);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int _encrypt(struct crypt_device *cd, const char *type, enum device_status_info dev_st, int action_argc, const char **action_argv)
 {
-	const char *data_device;
+	const char *device_ptr;
 	enum device_status_info data_dev_st;
+	struct stat st;
 	struct crypt_device *encrypt_cd = NULL;
 	int r = -EINVAL;
 
@@ -937,24 +953,37 @@ static int _encrypt(struct crypt_device *cd, const char *type, enum device_statu
 		return -EINVAL;
 	}
 
+	if (dev_st == DEVICE_NOT_LUKS &&
+	    (!ARG_SET(OPT_HEADER_ID) || !stat(ARG_STR(OPT_HEADER_ID), &st))) {
+		device_ptr = ARG_SET(OPT_HEADER_ID) ? ARG_STR(OPT_HEADER_ID) : action_argv[0];
+		r = check_broken_luks_signature(device_ptr);
+		if (r < 0)
+			return r;
+	}
+
 	/* check data device type/state */
 	if (ARG_SET(OPT_HEADER_ID)) {
-		data_device = cd ? crypt_get_device_name(cd) : action_argv[0];
-		data_dev_st = check_luks_device(data_device);
+		device_ptr = cd ? crypt_get_device_name(cd) : action_argv[0];
+		data_dev_st = check_luks_device(device_ptr);
+
 		if (data_dev_st == DEVICE_INVALID)
 			return -EINVAL;
 
 		if (data_dev_st == DEVICE_LUKS2 || data_dev_st == DEVICE_LUKS1) {
 			log_err(_("Device %s is already LUKS device. Aborting operation."),
-				data_device);
+				device_ptr);
 			return -EINVAL;
 		}
 
 		if (data_dev_st == DEVICE_LUKS2_REENCRYPT || data_dev_st == DEVICE_LUKS1_UNUSABLE) {
 			log_err(_("Device %s is already in LUKS reencryption. Aborting operation."),
-				data_device);
+				device_ptr);
 			return -EINVAL;
 		}
+
+		r = check_broken_luks_signature(device_ptr);
+		if (r < 0)
+			return r;
 	}
 
 	if (!type)

tests/luks2-reencryption-test

@@ -18,6 +18,7 @@ DEV_NAME=reenc9768
 DEV_NAME2=reenc97682
 IMG=reenc-data
 IMG_HDR=$IMG.hdr
+HEADER_LUKS2_PV=blkid-luks2-pv.img
 KEY1=key1
 VKEY1=vkey1
 PWD1="93R4P4pIqAH8"
@@ -98,7 +99,7 @@ function remove_mapping()
 	[ -b /dev/mapper/$OVRDEV-err ] && dmsetup remove --retry $OVRDEV-err 2>/dev/null
 	[ -n "$LOOPDEV" ] && losetup -d $LOOPDEV
 	unset LOOPDEV
-	rm -f $IMG $IMG_HDR $KEY1 $VKEY1 $DEVBIG $DEV_LINK >/dev/null 2>&1
+	rm -f $IMG $IMG_HDR $KEY1 $VKEY1 $DEVBIG $DEV_LINK $HEADER_LUKS2_PV >/dev/null 2>&1
 	rmmod scsi_debug >/dev/null 2>&1
 	scsi_debug_teardown $DEV
 }
@@ -1708,5 +1709,20 @@ echo $PWD1 | $CRYPTSETUP -q luksFormat --type luks2 --header $IMG_HDR $FAST_PBKD
 echo $PWD1 | $CRYPTSETUP reencrypt $DEV -q --decrypt --header $IMG_HDR --init-only $FAST_PBKDF_ARGON || fail
 echo $PWD1 | $CRYPTSETUP reencrypt --encrypt --header $IMG_HDR $DEV -q $FAST_PBKDF_ARGON 2> /dev/null && fail
 
+echo "[30] Prevent nested encryption of broken LUKS device"
+rm -f $IMG_HDR
+xz -dk $HEADER_LUKS2_PV.xz
+wipe_dev $DEV
+
+# broken header
+echo $PWD1 | $CRYPTSETUP reencrypt -q --header $HEADER_LUKS2_PV $DEV $FAST_PBKDF --encrypt --type luks2 2>/dev/null && fail
+$CRYPTSETUP isLuks $HEADER_LUKS2_PV && fail
+# broken device
+echo $PWD1 | $CRYPTSETUP reencrypt -q $HEADER_LUKS2_PV $FAST_PBKDF --encrypt --force-offline-reencrypt --type luks2 --reduce-device-size 8m 2>/dev/null && fail
+$CRYPTSETUP isLuks $HEADER_LUKS2_PV && fail
+# broken data device only
+echo $PWD1 | $CRYPTSETUP reencrypt -q --header $IMG_HDR $HEADER_LUKS2_PV $FAST_PBKDF --encrypt --force-offline-reencrypt --type luks2 2>/dev/null && fail
+test -f $IMG_HDR && fail
+
 remove_mapping
 exit 0

tests/reencryption-compat-test

@@ -10,6 +10,7 @@ DEV_NAME=reenc9768
 DEV_NAME2=reenc1273
 IMG=reenc-data
 IMG_HDR=$IMG.hdr
+HEADER_LUKS2_PV=blkid-luks2-pv.img
 ORIG_IMG=reenc-data-orig
 KEY1=key1
 PWD1="93R4P4pIqAH8"
@@ -30,7 +31,7 @@ function remove_mapping()
 	[ -b /dev/mapper/$DEV_NAME2 ] && dmsetup remove --retry $DEV_NAME2
 	[ -b /dev/mapper/$DEV_NAME ] && dmsetup remove --retry $DEV_NAME
 	[ ! -z "$LOOPDEV1" ] && losetup -d $LOOPDEV1 >/dev/null 2>&1
-	rm -f $IMG $IMG_HDR $ORIG_IMG $KEY1 >/dev/null 2>&1
+	rm -f $IMG $IMG_HDR $ORIG_IMG $KEY1 $HEADER_LUKS2_PV >/dev/null 2>&1
 	umount $MNT_DIR > /dev/null 2>&1
 	rmdir $MNT_DIR > /dev/null 2>&1
 	LOOPDEV1=""
@@ -416,5 +417,20 @@ echo $PWD1 | $CRYPTSETUP -q luksFormat --type luks1 --header $IMG_HDR $FAST_PBKD
 echo $PWD1 | $REENC $LOOPDEV1 -q $FAST_PBKDF --new --type luks1 --header $IMG_HDR  2>/dev/null && fail
 echo $PWD1 | $REENC $LOOPDEV1 -q $FAST_PBKDF --new --type luks2 --header $IMG_HDR  2>/dev/null && fail
 
+echo "[13] Prevent nested encryption of broken LUKS device"
+rm -f $IMG_HDR
+wipe_dev $LOOPDEV1
+xz -dk $HEADER_LUKS2_PV.xz
+
+# broken header
+echo $PWD1 | $REENC --header $HEADER_LUKS2_PV $LOOPDEV1 -q $FAST_PBKDF --new --type luks1 2>/dev/null && fail
+$CRYPTSETUP isLuks $HEADER_LUKS2_PV && fail
+# broken device
+echo $PWD1 | $REENC $HEADER_LUKS2_PV -q $FAST_PBKDF --new --type luks1 --reduce-device-size 1024S 2>/dev/null && fail
+$CRYPTSETUP isLuks $HEADER_LUKS2_PV && fail
+# broken data device only
+echo $PWD1 | $REENC --header $IMG_HDR $HEADER_LUKS2_PV -q $FAST_PBKDF --new --type luks1 2>/dev/null && fail
+test -f $IMG_HDR && fail
+
 remove_mapping
 exit 0