[PATCH v4 2/7] crypto: aead - disallow en/decrypt for non-task or non-softirq context
From: Ard Biesheuvel <ardb@kernel.org>
Date: 2021-05-19 11:22:59
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 AEAD encrypt and decrypt routines from outside of task or softirq context. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- crypto/aead.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/crypto/aead.c b/crypto/aead.c
index 16991095270d..141c9369b02a 100644
--- a/crypto/aead.c
+++ b/crypto/aead.c@@ -88,7 +88,11 @@ int crypto_aead_encrypt(struct aead_request *req) int ret; crypto_stats_get(alg); - if (crypto_aead_get_flags(aead) & 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_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY) ret = -ENOKEY; else ret = crypto_aead_alg(aead)->encrypt(req);
@@ -105,7 +109,11 @@ int crypto_aead_decrypt(struct aead_request *req) int ret; crypto_stats_get(alg); - if (crypto_aead_get_flags(aead) & 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_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY) ret = -ENOKEY; else if (req->cryptlen < crypto_aead_authsize(aead)) ret = -EINVAL;
--
2.20.1