From patchwork Sat Jun 27 08:36:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11629427 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7AFFE618 for ; Sat, 27 Jun 2020 08:37:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EF072137B for ; Sat, 27 Jun 2020 08:37:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593247037; bh=mJ44RN1Ax7UO5kUEhNQNsOxr9UMAVZrtpGUzPdPjV5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ibBYSXsLT5hWcjAOyHijZS4nDhyqpin3z+trAid6gX7apBZMHwMHCoXcIRWaNojax BIvBiEd/Ei0+GXMKXkTxRC0M3uslFE0Y5qHjmS/1rNre/evL8B7ObapbkESiaf9En+ Wd7cV9UoX1CCEDdmTh55In22sqO6YhIrsy1HaHaE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726421AbgF0IhQ (ORCPT ); Sat, 27 Jun 2020 04:37:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:33214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbgF0IhQ (ORCPT ); Sat, 27 Jun 2020 04:37:16 -0400 Received: from dogfood.home (lfbn-nic-1-188-42.w2-15.abo.wanadoo.fr [2.15.37.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B253C208C7; Sat, 27 Jun 2020 08:37:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593247035; bh=mJ44RN1Ax7UO5kUEhNQNsOxr9UMAVZrtpGUzPdPjV5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JJ8PGniKDwza/T069KYGviPChm/sq/A0O1/cXJD7D4b45EdSD5aBEtWIl1FxD/07T ay4A+7qicQGgq6mgO6mnvOk215t5E7vDxLo7DICzkND1FDakZfQMKX0CFjy2hI42UA IMkKpfDde2o0HFaHQTGSVI+ZbzwsivB1CLA9EFwY= From: Ard Biesheuvel To: linux-crypto@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-amlogic@lists.infradead.org, Ard Biesheuvel , Corentin Labbe , Herbert Xu , "David S. Miller" , Maxime Ripard , Chen-Yu Tsai , Tom Lendacky , Ayush Sawal , Vinay Kumar Yadav , Rohit Maheshwari , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Jamie Iles , Eric Biggers , Tero Kristo , Matthias Brugger Subject: [PATCH v2 09/13] crypto: mxs-dcp - permit asynchronous skcipher as fallback Date: Sat, 27 Jun 2020 10:36:19 +0200 Message-Id: <20200627083623.2428333-10-ardb@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200627083623.2428333-1-ardb@kernel.org> References: <20200627083623.2428333-1-ardb@kernel.org> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Even though the mxs-dcp driver implements asynchronous versions of ecb(aes) and cbc(aes), the fallbacks it allocates are required to be synchronous. Given that SIMD based software implementations are usually asynchronous as well, even though they rarely complete asynchronously (this typically only happens in cases where the request was made from softirq context, while SIMD was already in use in the task context that it interrupted), these implementations are disregarded, and either the generic C version or another table based version implemented in assembler is selected instead. Since falling back to synchronous AES is not only a performance issue, but potentially a security issue as well (due to the fact that table based AES is not time invariant), let's fix this, by allocating an ordinary skcipher as the fallback, and invoke it with the completion routine that was given to the outer request. Signed-off-by: Ard Biesheuvel --- drivers/crypto/mxs-dcp.c | 33 ++++++++++---------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c index d84530293036..909a7eb748e3 100644 --- a/drivers/crypto/mxs-dcp.c +++ b/drivers/crypto/mxs-dcp.c @@ -97,7 +97,7 @@ struct dcp_async_ctx { unsigned int hot:1; /* Crypto-specific context */ - struct crypto_sync_skcipher *fallback; + struct crypto_skcipher *fallback; unsigned int key_len; uint8_t key[AES_KEYSIZE_128]; }; @@ -105,6 +105,7 @@ struct dcp_async_ctx { struct dcp_aes_req_ctx { unsigned int enc:1; unsigned int ecb:1; + struct skcipher_request fallback_req; // keep at the end }; struct dcp_sha_req_ctx { @@ -426,21 +427,20 @@ static int dcp_chan_thread_aes(void *data) static int mxs_dcp_block_fallback(struct skcipher_request *req, int enc) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req); struct dcp_async_ctx *ctx = crypto_skcipher_ctx(tfm); - SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback); int ret; - skcipher_request_set_sync_tfm(subreq, ctx->fallback); - skcipher_request_set_callback(subreq, req->base.flags, NULL, NULL); - skcipher_request_set_crypt(subreq, req->src, req->dst, + skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback); + skcipher_request_set_callback(&rctx->fallback_req, req->base.flags, + req->base.complete, req->base.data); + skcipher_request_set_crypt(&rctx->fallback_req, req->src, req->dst, req->cryptlen, req->iv); if (enc) - ret = crypto_skcipher_encrypt(subreq); + ret = crypto_skcipher_encrypt(&rctx->fallback_req); else - ret = crypto_skcipher_decrypt(subreq); - - skcipher_request_zero(subreq); + ret = crypto_skcipher_decrypt(&rctx->fallback_req); return ret; } @@ -510,24 +510,25 @@ static int mxs_dcp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key, * but is supported by in-kernel software implementation, we use * software fallback. */ - crypto_sync_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK); - crypto_sync_skcipher_set_flags(actx->fallback, + crypto_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(actx->fallback, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); - return crypto_sync_skcipher_setkey(actx->fallback, key, len); + return crypto_skcipher_setkey(actx->fallback, key, len); } static int mxs_dcp_aes_fallback_init_tfm(struct crypto_skcipher *tfm) { const char *name = crypto_tfm_alg_name(crypto_skcipher_tfm(tfm)); struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm); - struct crypto_sync_skcipher *blk; + struct crypto_skcipher *blk; - blk = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); + blk = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); if (IS_ERR(blk)) return PTR_ERR(blk); actx->fallback = blk; - crypto_skcipher_set_reqsize(tfm, sizeof(struct dcp_aes_req_ctx)); + crypto_skcipher_set_reqsize(tfm, sizeof(struct dcp_aes_req_ctx) + + crypto_skcipher_reqsize(blk)); return 0; } @@ -535,7 +536,7 @@ static void mxs_dcp_aes_fallback_exit_tfm(struct crypto_skcipher *tfm) { struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm); - crypto_free_sync_skcipher(actx->fallback); + crypto_free_skcipher(actx->fallback); } /*