From patchwork Wed May 19 11:22:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 12267015 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92E11C433ED for ; Wed, 19 May 2021 11:23:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F5E36135F for ; Wed, 19 May 2021 11:23:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350133AbhESLYQ (ORCPT ); Wed, 19 May 2021 07:24:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:52858 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350260AbhESLYJ (ORCPT ); Wed, 19 May 2021 07:24:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E7118611BF; Wed, 19 May 2021 11:22:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621423370; bh=813vbDqlVp4TbHnw89ag9TrBuAfoPXQrAusOPwlb2rU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Brw1T6XE0yCFB5iVo+miBtWO8wz4UmajA8EcKnQkX+4YMT4KaR5x1w+u/43HZmBTY R5Lr+tI0o0GiEDOIV5/LeSboXD//qyI8cJMBUzwu+qisa5jWp6j04X66NfJfEXP9kQ jQUZ7EcX9TZzF2cBGylXEux4s8q2cFeIAjz2eLjbkZAouhtv9h4Q/v6k0gwOtq36xy 61NSvBJqQwaL0SUj2MdS/dDY3hGApJtK8OBBOmoRxIEvzTY5lkzchfsj85cN+XtKQw W/95vEJof393JQGZ0wNnOB7OhIAB2oH/36Iou+gUO6y6fjOwx6QC08XACLAeDV3ksS +K1NdC5y82KCg== From: Ard Biesheuvel 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 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 Message-Id: <20210519112239.33664-4-ardb@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210519112239.33664-1-ardb@kernel.org> References: <20210519112239.33664-1-ardb@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.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 --- 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);