[PATCH v2 5/9] crypto: skcipher - disallow en/decrypt for non-task or non-softirq context
From: Ard Biesheuvel <ardb@kernel.org>
Date: 2021-03-03 01:42:19
Also in:
linux-arm-kernel
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
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 --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;
--
2.30.1