bcache: Validate bkey formatbcache-dev-february

Change-Id: Ie30284518f55388925da92e7e0c4e13e77f54a90

3 files changed, 25 insertions, 0 deletions

diff --git a/drivers/md/bcache/bkey.c b/drivers/md/bcache/bkey.c
index ab3a034f407a..b60a2481f92e 100644
--- a/drivers/md/bcache/bkey.c
+++ b/drivers/md/bcache/bkey.c
@@ -296,6 +296,26 @@ struct bkey_format bch_bkey_format_done(struct bkey_format_state *s)
 	return ret;
 }
 
+const char *bch_bkey_format_validate(struct bkey_format *f)
+{
+	unsigned i, bits = KEY_PACKED_BITS_START;
+
+	if (f->nr_fields != BKEY_NR_FIELDS)
+		return "invalid format: incorrect number of fields";
+
+	for (i = 0; i < f->nr_fields; i++) {
+		if (f->bits_per_field[i] > 64)
+			return "invalid format: field too large";
+
+		bits += f->bits_per_field[i];
+	}
+
+	if (f->key_u64s != DIV_ROUND_UP(bits, 64))
+		return "invalid format: incorrect key_u64s";
+
+	return NULL;
+}
+
 /* Most significant differing bit */
 unsigned bkey_greatest_differing_bit(const struct bkey_format *format,
 				     const struct bkey_packed *l_k,
diff --git a/drivers/md/bcache/bkey.h b/drivers/md/bcache/bkey.h
index 666920d080f6..6ab9203b2fb0 100644
--- a/drivers/md/bcache/bkey.h
+++ b/drivers/md/bcache/bkey.h
@@ -57,6 +57,7 @@ void bch_bkey_format_init(struct bkey_format_state *);
 void bch_bkey_format_add_key(struct bkey_format_state *, struct bkey *);
 void bch_bkey_format_add_pos(struct bkey_format_state *, struct bpos);
 struct bkey_format bch_bkey_format_done(struct bkey_format_state *);
+const char *bch_bkey_format_validate(struct bkey_format *);
 
 unsigned bkey_greatest_differing_bit(const struct bkey_format *,
 				     const struct bkey_packed *,
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index c4f9851b8b78..1ca4629ee08e 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -348,6 +348,10 @@ void bch_btree_node_read_done(struct btree *b, struct cache *ca,
 	if (BSET_BTREE_LEVEL(i) != b->level)
 		goto err;
 
+	err = bch_bkey_format_validate(&b->data->format);
+	if (err)
+		goto err;
+
 	b->keys.format = b->data->format;
 	b->keys.set->data = &b->data->keys;