diff mbox series

[v2,5/9] crypto: skcipher - disallow en/decrypt for non-task or non-softirq context

Message ID 20210302090118.30666-6-ardb@kernel.org (mailing list archive)
State Not Applicable
Delegated to: Herbert Xu
Headers show
Series running kernel mode SIMD with softirqs disabled | expand

Commit Message

Ard Biesheuvel March 2, 2021, 9:01 a.m. UTC 
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 | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index a15376245416..d1a2ba6eacbe 100644
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -623,6 +623,11 @@  int crypto_skcipher_encrypt(struct skcipher_request *req)
 	unsigned int cryptlen = req->cryptlen;
 	int ret;
 
+	if (!(alg->cra_flags & CRYPTO_ALG_ASYNC) &&
+	    WARN_ONCE(!in_task() && !in_serving_softirq(),
+		      "synchronous call from invalid context\n"))
+		return -EBUSY;
+
 	crypto_stats_get(alg);
 	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 		ret = -ENOKEY;
@@ -640,6 +645,11 @@  int crypto_skcipher_decrypt(struct skcipher_request *req)
 	unsigned int cryptlen = req->cryptlen;
 	int ret;
 
+	if (!(alg->cra_flags & CRYPTO_ALG_ASYNC) &&
+	    WARN_ONCE(!in_task() && !in_serving_softirq(),
+		      "synchronous call from invalid context\n"))
+		return -EBUSY;
+
 	crypto_stats_get(alg);
 	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 		ret = -ENOKEY;