[Patch][Fix] crypto: arm{,64} neon: memzero_explicit aes-cbc key

[Torsten Duwe]

From: Torsten Duwe <duwe@xxxxxxx>

At function exit, do not leave the expanded key in the rk struct
which got allocated on the stack.

Signed-off-by: Torsten Duwe <duwe@xxxxxxx>
---
Another small fix from our FIPS evaluation. I hope you don't mind I merged
arm32 and arm64 into one patch -- this is really simple.
--- a/arch/arm/crypto/aes-neonbs-glue.c
+++ b/arch/arm/crypto/aes-neonbs-glue.c
@@ -138,6 +138,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 	kernel_neon_begin();
 	aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 	kernel_neon_end();
+	memzero_explicit(&rk, sizeof(rk));
 
 	return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len);
 }
diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
index e3e27349a9fe..c0b980503643 100644
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -151,6 +151,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 	kernel_neon_begin();
 	aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 	kernel_neon_end();
+	memzero_explicit(&rk, sizeof(rk));
 
 	return 0;
 }