[PATCH] crypto: arm/aes-neonbs - fix usage of cbc(aes) fallback

[Horia Geantă]

Loading the module deadlocks since:
-local cbc(aes) implementation needs a fallback and
-crypto API tries to find one but the request_module() resolves back to
the same module

Fix this by changing the module alias for cbc(aes) and
using the NEED_FALLBACK flag when requesting for a fallback algorithm.

Fixes: 00b99ad2bac2 ("crypto: arm/aes-neonbs - Use generic cbc encryption path")
Signed-off-by: Horia Geantă <horia.gea...@nxp.com>
---
 arch/arm/crypto/aes-neonbs-glue.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/arm/crypto/aes-neonbs-glue.c 
b/arch/arm/crypto/aes-neonbs-glue.c
index bda8bf17631e..f70af1d0514b 100644
--- a/arch/arm/crypto/aes-neonbs-glue.c
+++ b/arch/arm/crypto/aes-neonbs-glue.c
@@ -19,7 +19,7 @@ MODULE_AUTHOR("Ard Biesheuvel <ard.biesheu...@linaro.org>");
 MODULE_LICENSE("GPL v2");
 
 MODULE_ALIAS_CRYPTO("ecb(aes)");
-MODULE_ALIAS_CRYPTO("cbc(aes)");
+MODULE_ALIAS_CRYPTO("cbc(aes)-all");
 MODULE_ALIAS_CRYPTO("ctr(aes)");
 MODULE_ALIAS_CRYPTO("xts(aes)");
 
@@ -191,7 +191,8 @@ static int cbc_init(struct crypto_skcipher *tfm)
        struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
        unsigned int reqsize;
 
-       ctx->enc_tfm = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
+       ctx->enc_tfm = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC |
+                                            CRYPTO_ALG_NEED_FALLBACK);
        if (IS_ERR(ctx->enc_tfm))
                return PTR_ERR(ctx->enc_tfm);
 
@@ -441,7 +442,8 @@ static struct skcipher_alg aes_algs[] = { {
        .base.cra_blocksize     = AES_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct aesbs_cbc_ctx),
        .base.cra_module        = THIS_MODULE,
-       .base.cra_flags         = CRYPTO_ALG_INTERNAL,
+       .base.cra_flags         = CRYPTO_ALG_INTERNAL |
+                                 CRYPTO_ALG_NEED_FALLBACK,
 
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
-- 
2.17.1