crypto: x86/aegis - Add missing error checks

commit 3d9eb18 upstream.

The skcipher_walk functions can allocate memory and can fail, so
checking for errors is necessary.

Fixes: 1d373d4 ("crypto: x86 - Add optimized AEGIS implementations")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Eric Biggers

arch/x86/crypto/aegis128-aesni-glue.c

@@ -104,10 +104,12 @@ static void crypto_aegis128_aesni_process_ad(
 	}
 }
 
-static __always_inline void
+static __always_inline int
 crypto_aegis128_aesni_process_crypt(struct aegis_state *state,
 				    struct skcipher_walk *walk, bool enc)
 {
+	int err = 0;
+
 	while (walk->nbytes >= AEGIS128_BLOCK_SIZE) {
 		if (enc)
 			aegis128_aesni_enc(state, walk->src.virt.addr,
@@ -120,7 +122,8 @@ crypto_aegis128_aesni_process_crypt(struct aegis_state *state,
 					   round_down(walk->nbytes,
 						      AEGIS128_BLOCK_SIZE));
 		kernel_fpu_end();
-		skcipher_walk_done(walk, walk->nbytes % AEGIS128_BLOCK_SIZE);
+		err = skcipher_walk_done(walk,
+					 walk->nbytes % AEGIS128_BLOCK_SIZE);
 		kernel_fpu_begin();
 	}
 
@@ -134,9 +137,10 @@ crypto_aegis128_aesni_process_crypt(struct aegis_state *state,
 						walk->dst.virt.addr,
 						walk->nbytes);
 		kernel_fpu_end();
-		skcipher_walk_done(walk, 0);
+		err = skcipher_walk_done(walk, 0);
 		kernel_fpu_begin();
 	}
+	return err;
 }
 
 static struct aegis_ctx *crypto_aegis128_aesni_ctx(struct crypto_aead *aead)
@@ -169,7 +173,7 @@ static int crypto_aegis128_aesni_setauthsize(struct crypto_aead *tfm,
 	return 0;
 }
 
-static __always_inline void
+static __always_inline int
 crypto_aegis128_aesni_crypt(struct aead_request *req,
 			    struct aegis_block *tag_xor,
 			    unsigned int cryptlen, bool enc)
@@ -178,20 +182,24 @@ crypto_aegis128_aesni_crypt(struct aead_request *req,
 	struct aegis_ctx *ctx = crypto_aegis128_aesni_ctx(tfm);
 	struct skcipher_walk walk;
 	struct aegis_state state;
+	int err;
 
 	if (enc)
-		skcipher_walk_aead_encrypt(&walk, req, false);
+		err = skcipher_walk_aead_encrypt(&walk, req, false);
 	else
-		skcipher_walk_aead_decrypt(&walk, req, false);
+		err = skcipher_walk_aead_decrypt(&walk, req, false);
+	if (err)
+		return err;
 
 	kernel_fpu_begin();
 
 	aegis128_aesni_init(&state, &ctx->key, req->iv);
 	crypto_aegis128_aesni_process_ad(&state, req->src, req->assoclen);
-	crypto_aegis128_aesni_process_crypt(&state, &walk, enc);
-	aegis128_aesni_final(&state, tag_xor, req->assoclen, cryptlen);
-
+	err = crypto_aegis128_aesni_process_crypt(&state, &walk, enc);
+	if (err == 0)
+		aegis128_aesni_final(&state, tag_xor, req->assoclen, cryptlen);
 	kernel_fpu_end();
+	return err;
 }
 
 static int crypto_aegis128_aesni_encrypt(struct aead_request *req)
@@ -200,8 +208,11 @@ static int crypto_aegis128_aesni_encrypt(struct aead_request *req)
 	struct aegis_block tag = {};
 	unsigned int authsize = crypto_aead_authsize(tfm);
 	unsigned int cryptlen = req->cryptlen;
+	int err;
 
-	crypto_aegis128_aesni_crypt(req, &tag, cryptlen, true);
+	err = crypto_aegis128_aesni_crypt(req, &tag, cryptlen, true);
+	if (err)
+		return err;
 
 	scatterwalk_map_and_copy(tag.bytes, req->dst,
 				 req->assoclen + cryptlen, authsize, 1);
@@ -216,11 +227,14 @@ static int crypto_aegis128_aesni_decrypt(struct aead_request *req)
 	struct aegis_block tag;
 	unsigned int authsize = crypto_aead_authsize(tfm);
 	unsigned int cryptlen = req->cryptlen - authsize;
+	int err;
 
 	scatterwalk_map_and_copy(tag.bytes, req->src,
 				 req->assoclen + cryptlen, authsize, 0);
 
-	crypto_aegis128_aesni_crypt(req, &tag, cryptlen, false);
+	err = crypto_aegis128_aesni_crypt(req, &tag, cryptlen, false);
+	if (err)
+		return err;
 
 	return crypto_memneq(tag.bytes, zeros.bytes, authsize) ? -EBADMSG : 0;
 }