From mboxrd@z Thu Jan 1 00:00:00 1970 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, 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 EB8C6C433E6 for ; Mon, 1 Mar 2021 20:26:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7E99601FD for ; Mon, 1 Mar 2021 20:26:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242632AbhCAUZf (ORCPT ); Mon, 1 Mar 2021 15:25:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:45770 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243211AbhCAUSz (ORCPT ); Mon, 1 Mar 2021 15:18:55 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 44465653E0; Mon, 1 Mar 2021 18:03:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614621793; bh=IcTdTKUdRz82ut84jVSWQPuXkYg+kRy4McALB7/uNfU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dnoVj4o0TcPY6PV1umfQOSiG8ysjuCUvPlQON0ZKBwgaF9qw6shEwTIhDPK0vA3WS sEnv9WTca4dZ3Nl01A5PdH7yeIiyWtHubpZ9oPhsZIN1z7PM7xmFnkVRYoudWOc5gY 0ahWTZ8xP6EF5EkDzoKV/wIe0mQ4DxYxQQ0Kvy5k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Herbert Xu Subject: [PATCH 5.11 646/775] crypto: aesni - prevent misaligned buffers on the stack Date: Mon, 1 Mar 2021 17:13:34 +0100 Message-Id: <20210301161233.322679990@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161201.679371205@linuxfoundation.org> References: <20210301161201.679371205@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ard Biesheuvel commit a13ed1d15b07a04b1f74b2df61ff7a5e47f45dd8 upstream. The GCM mode driver uses 16 byte aligned buffers on the stack to pass the IV to the asm helpers, but unfortunately, the x86 port does not guarantee that the stack pointer is 16 byte aligned upon entry in the first place. Since the compiler is not aware of this, it will not emit the additional stack realignment sequence that is needed, and so the alignment is not guaranteed to be more than 8 bytes. So instead, allocate some padding on the stack, and realign the IV pointer by hand. Cc: Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- arch/x86/crypto/aesni-intel_glue.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -686,7 +686,8 @@ static int gcmaes_crypt_by_sg(bool enc, struct crypto_aead *tfm = crypto_aead_reqtfm(req); unsigned long auth_tag_len = crypto_aead_authsize(tfm); const struct aesni_gcm_tfm_s *gcm_tfm = aesni_gcm_tfm; - struct gcm_context_data data AESNI_ALIGN_ATTR; + u8 databuf[sizeof(struct gcm_context_data) + (AESNI_ALIGN - 8)] __aligned(8); + struct gcm_context_data *data = PTR_ALIGN((void *)databuf, AESNI_ALIGN); struct scatter_walk dst_sg_walk = {}; unsigned long left = req->cryptlen; unsigned long len, srclen, dstlen; @@ -735,8 +736,7 @@ static int gcmaes_crypt_by_sg(bool enc, } kernel_fpu_begin(); - gcm_tfm->init(aes_ctx, &data, iv, - hash_subkey, assoc, assoclen); + gcm_tfm->init(aes_ctx, data, iv, hash_subkey, assoc, assoclen); if (req->src != req->dst) { while (left) { src = scatterwalk_map(&src_sg_walk); @@ -746,10 +746,10 @@ static int gcmaes_crypt_by_sg(bool enc, len = min(srclen, dstlen); if (len) { if (enc) - gcm_tfm->enc_update(aes_ctx, &data, + gcm_tfm->enc_update(aes_ctx, data, dst, src, len); else - gcm_tfm->dec_update(aes_ctx, &data, + gcm_tfm->dec_update(aes_ctx, data, dst, src, len); } left -= len; @@ -767,10 +767,10 @@ static int gcmaes_crypt_by_sg(bool enc, len = scatterwalk_clamp(&src_sg_walk, left); if (len) { if (enc) - gcm_tfm->enc_update(aes_ctx, &data, + gcm_tfm->enc_update(aes_ctx, data, src, src, len); else - gcm_tfm->dec_update(aes_ctx, &data, + gcm_tfm->dec_update(aes_ctx, data, src, src, len); } left -= len; @@ -779,7 +779,7 @@ static int gcmaes_crypt_by_sg(bool enc, scatterwalk_done(&src_sg_walk, 1, left); } } - gcm_tfm->finalize(aes_ctx, &data, authTag, auth_tag_len); + gcm_tfm->finalize(aes_ctx, data, authTag, auth_tag_len); kernel_fpu_end(); if (!assocmem) @@ -828,7 +828,8 @@ static int helper_rfc4106_encrypt(struct struct crypto_aead *tfm = crypto_aead_reqtfm(req); struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(tfm); void *aes_ctx = &(ctx->aes_key_expanded); - u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN))); + u8 ivbuf[16 + (AESNI_ALIGN - 8)] __aligned(8); + u8 *iv = PTR_ALIGN(&ivbuf[0], AESNI_ALIGN); unsigned int i; __be32 counter = cpu_to_be32(1); @@ -855,7 +856,8 @@ static int helper_rfc4106_decrypt(struct struct crypto_aead *tfm = crypto_aead_reqtfm(req); struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(tfm); void *aes_ctx = &(ctx->aes_key_expanded); - u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN))); + u8 ivbuf[16 + (AESNI_ALIGN - 8)] __aligned(8); + u8 *iv = PTR_ALIGN(&ivbuf[0], AESNI_ALIGN); unsigned int i; if (unlikely(req->assoclen != 16 && req->assoclen != 20)) @@ -985,7 +987,8 @@ static int generic_gcmaes_encrypt(struct struct crypto_aead *tfm = crypto_aead_reqtfm(req); struct generic_gcmaes_ctx *ctx = generic_gcmaes_ctx_get(tfm); void *aes_ctx = &(ctx->aes_key_expanded); - u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN))); + u8 ivbuf[16 + (AESNI_ALIGN - 8)] __aligned(8); + u8 *iv = PTR_ALIGN(&ivbuf[0], AESNI_ALIGN); __be32 counter = cpu_to_be32(1); memcpy(iv, req->iv, 12); @@ -1001,7 +1004,8 @@ static int generic_gcmaes_decrypt(struct struct crypto_aead *tfm = crypto_aead_reqtfm(req); struct generic_gcmaes_ctx *ctx = generic_gcmaes_ctx_get(tfm); void *aes_ctx = &(ctx->aes_key_expanded); - u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN))); + u8 ivbuf[16 + (AESNI_ALIGN - 8)] __aligned(8); + u8 *iv = PTR_ALIGN(&ivbuf[0], AESNI_ALIGN); memcpy(iv, req->iv, 12); *((__be32 *)(iv+12)) = counter;