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From: Ard Biesheuvel <ardb@kernel.org>
To: linux-crypto@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org, ebiggers@kernel.org,
	herbert@gondor.apana.org.au, will@kernel.org,
	kernel-team@android.com, Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH v4 3/7] crypto: skcipher - disallow en/decrypt for non-task or non-softirq context
Date: Wed, 19 May 2021 13:22:35 +0200	[thread overview]
Message-ID: <20210519112239.33664-4-ardb@kernel.org> (raw)
In-Reply-To: <20210519112239.33664-1-ardb@kernel.org>

In order to ensure that kernel mode SIMD routines will not need a scalar
fallback if they run with softirqs disabled, disallow any use of the
skcipher encrypt and decrypt routines from outside of task or softirq
context.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 crypto/skcipher.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index ed2deb031742..f69492aab75d 100644
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -628,7 +628,11 @@ int crypto_skcipher_encrypt(struct skcipher_request *req)
 	int ret;
 
 	crypto_stats_get(alg);
-	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+	if (!(alg->cra_flags & CRYPTO_ALG_ASYNC) &&
+	    WARN_ONCE(!in_task() && !in_serving_softirq(),
+		      "synchronous call from invalid context\n"))
+		ret = -EBUSY;
+	else if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 		ret = -ENOKEY;
 	else
 		ret = crypto_skcipher_alg(tfm)->encrypt(req);
@@ -645,7 +649,11 @@ int crypto_skcipher_decrypt(struct skcipher_request *req)
 	int ret;
 
 	crypto_stats_get(alg);
-	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+	if (!(alg->cra_flags & CRYPTO_ALG_ASYNC) &&
+	    WARN_ONCE(!in_task() && !in_serving_softirq(),
+		      "synchronous call from invalid context\n"))
+		ret = -EBUSY;
+	else if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 		ret = -ENOKEY;
 	else
 		ret = crypto_skcipher_alg(tfm)->decrypt(req);
-- 
2.20.1


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  parent reply	other threads:[~2021-05-19 12:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-19 11:22 [PATCH v4 0/7] running kernel mode SIMD with softirqs disabled Ard Biesheuvel
2021-05-19 11:22 ` [PATCH v4 1/7] crypto: skcipher - handle zero sized inputs correctly Ard Biesheuvel
2021-05-19 11:22 ` [PATCH v4 2/7] crypto: aead - disallow en/decrypt for non-task or non-softirq context Ard Biesheuvel
2021-05-19 11:29   ` Herbert Xu
2021-05-19 11:36     ` Ard Biesheuvel
2021-05-19 11:51       ` Herbert Xu
2021-05-21  7:30         ` Ard Biesheuvel
2021-05-19 11:22 ` Ard Biesheuvel [this message]
2021-05-19 11:22 ` [PATCH v4 4/7] crypto: arm64/gcm-aes-ce - remove non-SIMD fallback path Ard Biesheuvel
2021-05-19 11:22 ` [PATCH v4 5/7] crypto: arm64/aes-neonbs - stop using SIMD helper for skciphers Ard Biesheuvel
2021-05-19 11:22 ` [PATCH v4 6/7] crypto: arm64/aes-ce " Ard Biesheuvel
2021-05-19 11:22 ` [PATCH v4 7/7] crypto: arm64/aes-ccm - remove non-SIMD fallback path Ard Biesheuvel

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