1 files changed, 201 insertions, 23 deletions

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 5a7a1b90e671..46b5d542b8fe 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -40,6 +40,7 @@
 #define BITMAP_BLOCK_SIZE		4096	/* don't change it */
 #define BITMAP_FLUSH_INTERVAL		(10 * HZ)
 #define DISCARD_FILLER			0xf6
+#define SALT_SIZE			16
 
 /*
  * Warning - DEBUG_PRINT prints security-sensitive data to the log,
@@ -57,6 +58,7 @@
 #define SB_VERSION_2			2
 #define SB_VERSION_3			3
 #define SB_VERSION_4			4
+#define SB_VERSION_5			5
 #define SB_SECTORS			8
 #define MAX_SECTORS_PER_BLOCK		8
 
@@ -72,12 +74,15 @@ struct superblock {
 	__u8 log2_blocks_per_bitmap_bit;
 	__u8 pad[2];
 	__u64 recalc_sector;
+	__u8 pad2[8];
+	__u8 salt[SALT_SIZE];
 };
 
 #define SB_FLAG_HAVE_JOURNAL_MAC	0x1
 #define SB_FLAG_RECALCULATING		0x2
 #define SB_FLAG_DIRTY_BITMAP		0x4
 #define SB_FLAG_FIXED_PADDING		0x8
+#define SB_FLAG_FIXED_HMAC		0x10
 
 #define	JOURNAL_ENTRY_ROUNDUP		8
 
@@ -257,8 +262,10 @@ struct dm_integrity_c {
 	bool journal_uptodate;
 	bool just_formatted;
 	bool recalculate_flag;
-	bool fix_padding;
 	bool discard;
+	bool fix_padding;
+	bool fix_hmac;
+	bool legacy_recalculate;
 
 	struct alg_spec internal_hash_alg;
 	struct alg_spec journal_crypt_alg;
@@ -386,6 +393,17 @@ static int dm_integrity_failed(struct dm_integrity_c *ic)
 	return READ_ONCE(ic->failed);
 }
 
+static bool dm_integrity_disable_recalculate(struct dm_integrity_c *ic)
+{
+	if (ic->legacy_recalculate)
+		return false;
+	if (!(ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) ?
+	    ic->internal_hash_alg.key || ic->journal_mac_alg.key :
+	    ic->internal_hash_alg.key && !ic->journal_mac_alg.key)
+		return true;
+	return false;
+}
+
 static commit_id_t dm_integrity_commit_id(struct dm_integrity_c *ic, unsigned i,
 					  unsigned j, unsigned char seq)
 {
@@ -468,7 +486,9 @@ static void wraparound_section(struct dm_integrity_c *ic, unsigned *sec_ptr)
 
 static void sb_set_version(struct dm_integrity_c *ic)
 {
-	if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING))
+	if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC))
+		ic->sb->version = SB_VERSION_5;
+	else if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING))
 		ic->sb->version = SB_VERSION_4;
 	else if (ic->mode == 'B' || ic->sb->flags & cpu_to_le32(SB_FLAG_DIRTY_BITMAP))
 		ic->sb->version = SB_VERSION_3;
@@ -478,10 +498,58 @@ static void sb_set_version(struct dm_integrity_c *ic)
 		ic->sb->version = SB_VERSION_1;
 }
 
+static int sb_mac(struct dm_integrity_c *ic, bool wr)
+{
+	SHASH_DESC_ON_STACK(desc, ic->journal_mac);
+	int r;
+	unsigned size = crypto_shash_digestsize(ic->journal_mac);
+
+	if (sizeof(struct superblock) + size > 1 << SECTOR_SHIFT) {
+		dm_integrity_io_error(ic, "digest is too long", -EINVAL);
+		return -EINVAL;
+	}
+
+	desc->tfm = ic->journal_mac;
+
+	r = crypto_shash_init(desc);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_init", r);
+		return r;
+	}
+
+	r = crypto_shash_update(desc, (__u8 *)ic->sb, (1 << SECTOR_SHIFT) - size);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_update", r);
+		return r;
+	}
+
+	if (likely(wr)) {
+		r = crypto_shash_final(desc, (__u8 *)ic->sb + (1 << SECTOR_SHIFT) - size);
+		if (unlikely(r < 0)) {
+			dm_integrity_io_error(ic, "crypto_shash_final", r);
+			return r;
+		}
+	} else {
+		__u8 result[HASH_MAX_DIGESTSIZE];
+		r = crypto_shash_final(desc, result);
+		if (unlikely(r < 0)) {
+			dm_integrity_io_error(ic, "crypto_shash_final", r);
+			return r;
+		}
+		if (memcmp((__u8 *)ic->sb + (1 << SECTOR_SHIFT) - size, result, size)) {
+			dm_integrity_io_error(ic, "superblock mac", -EILSEQ);
+			return -EILSEQ;
+		}
+	}
+
+	return 0;
+}
+
 static int sync_rw_sb(struct dm_integrity_c *ic, int op, int op_flags)
 {
 	struct dm_io_request io_req;
 	struct dm_io_region io_loc;
+	int r;
 
 	io_req.bi_op = op;
 	io_req.bi_op_flags = op_flags;
@@ -493,10 +561,28 @@ static int sync_rw_sb(struct dm_integrity_c *ic, int op, int op_flags)
 	io_loc.sector = ic->start;
 	io_loc.count = SB_SECTORS;
 
-	if (op == REQ_OP_WRITE)
+	if (op == REQ_OP_WRITE) {
 		sb_set_version(ic);
+		if (ic->journal_mac && ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
+			r = sb_mac(ic, true);
+			if (unlikely(r))
+				return r;
+		}
+	}
+
+	r = dm_io(&io_req, 1, &io_loc, NULL);
+	if (unlikely(r))
+		return r;
+
+	if (op == REQ_OP_READ) {
+		if (ic->mode != 'R' && ic->journal_mac && ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
+			r = sb_mac(ic, false);
+			if (unlikely(r))
+				return r;
+		}
+	}
 
-	return dm_io(&io_req, 1, &io_loc, NULL);
+	return 0;
 }
 
 #define BITMAP_OP_TEST_ALL_SET		0
@@ -713,15 +799,32 @@ static void section_mac(struct dm_integrity_c *ic, unsigned section, __u8 result
 	desc->tfm = ic->journal_mac;
 
 	r = crypto_shash_init(desc);
-	if (unlikely(r)) {
+	if (unlikely(r < 0)) {
 		dm_integrity_io_error(ic, "crypto_shash_init", r);
 		goto err;
 	}
 
+	if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
+		uint64_t section_le;
+
+		r = crypto_shash_update(desc, (__u8 *)&ic->sb->salt, SALT_SIZE);
+		if (unlikely(r < 0)) {
+			dm_integrity_io_error(ic, "crypto_shash_update", r);
+			goto err;
+		}
+
+		section_le = cpu_to_le64(section);
+		r = crypto_shash_update(desc, (__u8 *)&section_le, sizeof section_le);
+		if (unlikely(r < 0)) {
+			dm_integrity_io_error(ic, "crypto_shash_update", r);
+			goto err;
+		}
+	}
+
 	for (j = 0; j < ic->journal_section_entries; j++) {
 		struct journal_entry *je = access_journal_entry(ic, section, j);
 		r = crypto_shash_update(desc, (__u8 *)&je->u.sector, sizeof je->u.sector);
-		if (unlikely(r)) {
+		if (unlikely(r < 0)) {
 			dm_integrity_io_error(ic, "crypto_shash_update", r);
 			goto err;
 		}
@@ -731,7 +834,7 @@ static void section_mac(struct dm_integrity_c *ic, unsigned section, __u8 result
 
 	if (likely(size <= JOURNAL_MAC_SIZE)) {
 		r = crypto_shash_final(desc, result);
-		if (unlikely(r)) {
+		if (unlikely(r < 0)) {
 			dm_integrity_io_error(ic, "crypto_shash_final", r);
 			goto err;
 		}
@@ -744,7 +847,7 @@ static void section_mac(struct dm_integrity_c *ic, unsigned section, __u8 result
 			goto err;
 		}
 		r = crypto_shash_final(desc, digest);
-		if (unlikely(r)) {
+		if (unlikely(r < 0)) {
 			dm_integrity_io_error(ic, "crypto_shash_final", r);
 			goto err;
 		}
@@ -1379,12 +1482,52 @@ thorough_test:
 #undef MAY_BE_HASH
 }
 
-static void dm_integrity_flush_buffers(struct dm_integrity_c *ic)
+struct flush_request {
+	struct dm_io_request io_req;
+	struct dm_io_region io_reg;
+	struct dm_integrity_c *ic;
+	struct completion comp;
+};
+
+static void flush_notify(unsigned long error, void *fr_)
+{
+	struct flush_request *fr = fr_;
+	if (unlikely(error != 0))
+		dm_integrity_io_error(fr->ic, "flushing disk cache", -EIO);
+	complete(&fr->comp);
+}
+
+static void dm_integrity_flush_buffers(struct dm_integrity_c *ic, bool flush_data)
 {
 	int r;
+
+	struct flush_request fr;
+
+	if (!ic->meta_dev)
+		flush_data = false;
+	if (flush_data) {
+		fr.io_req.bi_op = REQ_OP_WRITE,
+		fr.io_req.bi_op_flags = REQ_PREFLUSH | REQ_SYNC,
+		fr.io_req.mem.type = DM_IO_KMEM,
+		fr.io_req.mem.ptr.addr = NULL,
+		fr.io_req.notify.fn = flush_notify,
+		fr.io_req.notify.context = &fr;
+		fr.io_req.client = dm_bufio_get_dm_io_client(ic->bufio),
+		fr.io_reg.bdev = ic->dev->bdev,
+		fr.io_reg.sector = 0,
+		fr.io_reg.count = 0,
+		fr.ic = ic;
+		init_completion(&fr.comp);
+		r = dm_io(&fr.io_req, 1, &fr.io_reg, NULL);
+		BUG_ON(r);
+	}
+
 	r = dm_bufio_write_dirty_buffers(ic->bufio);
 	if (unlikely(r))
 		dm_integrity_io_error(ic, "writing tags", r);
+
+	if (flush_data)
+		wait_for_completion(&fr.comp);
 }
 
 static void sleep_on_endio_wait(struct dm_integrity_c *ic)
@@ -1507,6 +1650,14 @@ static void integrity_sector_checksum(struct dm_integrity_c *ic, sector_t sector
 		goto failed;
 	}
 
+	if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
+		r = crypto_shash_update(req, (__u8 *)&ic->sb->salt, SALT_SIZE);
+		if (unlikely(r < 0)) {
+			dm_integrity_io_error(ic, "crypto_shash_update", r);
+			goto failed;
+		}
+	}
+
 	r = crypto_shash_update(req, (const __u8 *)&sector_le, sizeof sector_le);
 	if (unlikely(r < 0)) {
 		dm_integrity_io_error(ic, "crypto_shash_update", r);
@@ -2110,7 +2261,7 @@ offload_to_thread:
 
 	if (unlikely(dio->op == REQ_OP_DISCARD) && likely(ic->mode != 'D')) {
 		integrity_metadata(&dio->work);
-		dm_integrity_flush_buffers(ic);
+		dm_integrity_flush_buffers(ic, false);
 
 		dio->in_flight = (atomic_t)ATOMIC_INIT(1);
 		dio->completion = NULL;
@@ -2195,7 +2346,7 @@ static void integrity_commit(struct work_struct *w)
 	flushes = bio_list_get(&ic->flush_bio_list);
 	if (unlikely(ic->mode != 'J')) {
 		spin_unlock_irq(&ic->endio_wait.lock);
-		dm_integrity_flush_buffers(ic);
+		dm_integrity_flush_buffers(ic, true);
 		goto release_flush_bios;
 	}
 
@@ -2409,7 +2560,7 @@ skip_io:
 	complete_journal_op(&comp);
 	wait_for_completion_io(&comp.comp);
 
-	dm_integrity_flush_buffers(ic);
+	dm_integrity_flush_buffers(ic, true);
 }
 
 static void integrity_writer(struct work_struct *w)
@@ -2451,7 +2602,7 @@ static void recalc_write_super(struct dm_integrity_c *ic)
 {
 	int r;
 
-	dm_integrity_flush_buffers(ic);
+	dm_integrity_flush_buffers(ic, false);
 	if (dm_integrity_failed(ic))
 		return;
 
@@ -2654,7 +2805,7 @@ static void bitmap_flush_work(struct work_struct *work)
 	unsigned long limit;
 	struct bio *bio;
 
-	dm_integrity_flush_buffers(ic);
+	dm_integrity_flush_buffers(ic, false);
 
 	range.logical_sector = 0;
 	range.n_sectors = ic->provided_data_sectors;
@@ -2663,9 +2814,7 @@ static void bitmap_flush_work(struct work_struct *work)
 	add_new_range_and_wait(ic, &range);
 	spin_unlock_irq(&ic->endio_wait.lock);
 
-	dm_integrity_flush_buffers(ic);
-	if (ic->meta_dev)
-		blkdev_issue_flush(ic->dev->bdev, GFP_NOIO);
+	dm_integrity_flush_buffers(ic, true);
 
 	limit = ic->provided_data_sectors;
 	if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
@@ -2934,11 +3083,11 @@ static void dm_integrity_postsuspend(struct dm_target *ti)
 		if (ic->meta_dev)
 			queue_work(ic->writer_wq, &ic->writer_work);
 		drain_workqueue(ic->writer_wq);
-		dm_integrity_flush_buffers(ic);
+		dm_integrity_flush_buffers(ic, true);
 	}
 
 	if (ic->mode == 'B') {
-		dm_integrity_flush_buffers(ic);
+		dm_integrity_flush_buffers(ic, true);
 #if 1
 		/* set to 0 to test bitmap replay code */
 		init_journal(ic, 0, ic->journal_sections, 0);
@@ -3102,6 +3251,8 @@ static void dm_integrity_status(struct dm_target *ti, status_type_t type,
 		arg_count += !!ic->journal_crypt_alg.alg_string;
 		arg_count += !!ic->journal_mac_alg.alg_string;
 		arg_count += (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING)) != 0;
+		arg_count += (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) != 0;
+		arg_count += ic->legacy_recalculate;
 		DMEMIT("%s %llu %u %c %u", ic->dev->name, ic->start,
 		       ic->tag_size, ic->mode, arg_count);
 		if (ic->meta_dev)
@@ -3125,6 +3276,10 @@ static void dm_integrity_status(struct dm_target *ti, status_type_t type,
 		}
 		if ((ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING)) != 0)
 			DMEMIT(" fix_padding");
+		if ((ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) != 0)
+			DMEMIT(" fix_hmac");
+		if (ic->legacy_recalculate)
+			DMEMIT(" legacy_recalculate");
 
 #define EMIT_ALG(a, n)							\
 		do {							\
@@ -3260,6 +3415,11 @@ static int initialize_superblock(struct dm_integrity_c *ic, unsigned journal_sec
 	if (!journal_sections)
 		journal_sections = 1;
 
+	if (ic->fix_hmac && (ic->internal_hash_alg.alg_string || ic->journal_mac_alg.alg_string)) {
+		ic->sb->flags |= cpu_to_le32(SB_FLAG_FIXED_HMAC);
+		get_random_bytes(ic->sb->salt, SALT_SIZE);
+	}
+
 	if (!ic->meta_dev) {
 		if (ic->fix_padding)
 			ic->sb->flags |= cpu_to_le32(SB_FLAG_FIXED_PADDING);
@@ -3754,7 +3914,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 	unsigned extra_args;
 	struct dm_arg_set as;
 	static const struct dm_arg _args[] = {
-		{0, 9, "Invalid number of feature args"},
+		{0, 17, "Invalid number of feature args"},
 	};
 	unsigned journal_sectors, interleave_sectors, buffer_sectors, journal_watermark, sync_msec;
 	bool should_write_sb;
@@ -3892,7 +4052,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 			if (r)
 				goto bad;
 		} else if (!strncmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
-			r = get_alg_and_key(opt_string, &ic->journal_mac_alg,  &ti->error,
+			r = get_alg_and_key(opt_string, &ic->journal_mac_alg, &ti->error,
 					    "Invalid journal_mac argument");
 			if (r)
 				goto bad;
@@ -3902,6 +4062,10 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 			ic->discard = true;
 		} else if (!strcmp(opt_string, "fix_padding")) {
 			ic->fix_padding = true;
+		} else if (!strcmp(opt_string, "fix_hmac")) {
+			ic->fix_hmac = true;
+		} else if (!strcmp(opt_string, "legacy_recalculate")) {
+			ic->legacy_recalculate = true;
 		} else {
 			r = -EINVAL;
 			ti->error = "Invalid argument";
@@ -4058,7 +4222,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 			should_write_sb = true;
 	}
 
-	if (!ic->sb->version || ic->sb->version > SB_VERSION_4) {
+	if (!ic->sb->version || ic->sb->version > SB_VERSION_5) {
 		r = -EINVAL;
 		ti->error = "Unknown version";
 		goto bad;
@@ -4197,6 +4361,20 @@ try_smaller_buffer:
 			r = -ENOMEM;
 			goto bad;
 		}
+	} else {
+		if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
+			ti->error = "Recalculate can only be specified with internal_hash";
+			r = -EINVAL;
+			goto bad;
+		}
+	}
+
+	if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING) &&
+	    le64_to_cpu(ic->sb->recalc_sector) < ic->provided_data_sectors &&
+	    dm_integrity_disable_recalculate(ic)) {
+		ti->error = "Recalculating with HMAC is disabled for security reasons - if you really need it, use the argument \"legacy_recalculate\"";
+		r = -EOPNOTSUPP;
+		goto bad;
 	}
 
 	ic->bufio = dm_bufio_client_create(ic->meta_dev ? ic->meta_dev->bdev : ic->dev->bdev,
@@ -4376,7 +4554,7 @@ static void dm_integrity_dtr(struct dm_target *ti)
 
 static struct target_type integrity_target = {
 	.name			= "integrity",
-	.version		= {1, 6, 0},
+	.version		= {1, 7, 0},
 	.module			= THIS_MODULE,
 	.features		= DM_TARGET_SINGLETON | DM_TARGET_INTEGRITY,
 	.ctr			= dm_integrity_ctr,