crypto: xts - Propagate NEED_FALLBACK bit

When we're used as a fallback algorithm, we should propagate the NEED_FALLBACK bit when searching for the underlying ECB mode. This just happens to fix a hang too because otherwise the search may end up loading the same module that triggered this XTS creation. Cc: [email protected] #4.10 Fixes: f1c131b ("crypto: xts - Convert to skcipher") Reported-by: Harald Freudenberger <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
chewitt · Feb 27, 2017 · 8902757 · 8902757
1 parent 016df0a
commit 8902757
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/crypto/xts.c b/crypto/xts.c
@@ -463,6 +463,7 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 	struct xts_instance_ctx *ctx;
 	struct skcipher_alg *alg;
 	const char *cipher_name;
+	u32 mask;
 	int err;
 
 	algt = crypto_get_attr_type(tb);
@@ -483,18 +484,19 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 	ctx = skcipher_instance_ctx(inst);
 
 	crypto_set_skcipher_spawn(&ctx->spawn, skcipher_crypto_instance(inst));
-	err = crypto_grab_skcipher(&ctx->spawn, cipher_name, 0,
-				   crypto_requires_sync(algt->type,
-							algt->mask));
+
+	mask = crypto_requires_off(algt->type, algt->mask,
+				   CRYPTO_ALG_NEED_FALLBACK |
+				   CRYPTO_ALG_ASYNC);
+
+	err = crypto_grab_skcipher(&ctx->spawn, cipher_name, 0, mask);
 	if (err == -ENOENT) {
 		err = -ENAMETOOLONG;
 		if (snprintf(ctx->name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
 			     cipher_name) >= CRYPTO_MAX_ALG_NAME)
 			goto err_free_inst;
 
-		err = crypto_grab_skcipher(&ctx->spawn, ctx->name, 0,
-					   crypto_requires_sync(algt->type,
-								algt->mask));
+		err = crypto_grab_skcipher(&ctx->spawn, ctx->name, 0, mask);
 	}
 
 	if (err)