From patchwork Fri Oct 23 19:21:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arvind Sankar X-Patchwork-Id: 11854449 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 AA723C388F9 for ; Fri, 23 Oct 2020 19:22:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60EAF206DC for ; Fri, 23 Oct 2020 19:22:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754141AbgJWTWI (ORCPT ); Fri, 23 Oct 2020 15:22:08 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:44540 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750844AbgJWTWH (ORCPT ); Fri, 23 Oct 2020 15:22:07 -0400 Received: by mail-qt1-f195.google.com with SMTP id m65so1815195qte.11; Fri, 23 Oct 2020 12:22:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=WaiSZM/zHLv+SM8aG+Xi49iKWwDUu00ZSVCNFd+ZJGs=; b=Z/Ydp5l/AvCHjWW1VKrtutnIQLhW7PIL2RaC0pc1yU9u+uGymeYowGFBwtNhKGy7Rx m4s3ZUjmUalVexVhsG6eWGiQli/IvhBVMsZxkVlfY0AtReqggVog3+B0dV/VD8pbFNuG cD+LoE+DewMhcXeJBBpqqTC+AHE3UoUr/N/BRPSAaiHuPUsdkyxp3kZsEgvXiPAJL01Z hBTPkwl8RflQLs+fcQFfXwV61ZH60kU+KIRkYsBQmTLymCpQLVkrVZcPs/OFgqT+YuDr BlGhJDGI/kfjAEf7Ug6EX5IZxvNCa4aTIjo3A2FfPAswCAPZPTWPZ3eblm09uD6LHleu GvWA== X-Gm-Message-State: AOAM5302P/1yuR9/PFMTPNMH1Z9+3h8ryO/I146MBXUomVBCyHmfse08 PnpFKODMBLrUiLLlJ5RTCUKwvmneFXpNgA== X-Google-Smtp-Source: ABdhPJytdwI+3HmIDdQi7x7r8HKnTSFaLNhqau7lJt0ZB5UiXnBLv+RF4MalVjpqB3HF1pY7R+M1gQ== X-Received: by 2002:ac8:58ce:: with SMTP id u14mr3720555qta.56.1603480925844; Fri, 23 Oct 2020 12:22:05 -0700 (PDT) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id n199sm1398493qkn.77.2020.10.23.12.22.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Oct 2020 12:22:05 -0700 (PDT) From: Arvind Sankar To: Herbert Xu , "David S. Miller" , "linux-crypto@vger.kernel.org" , Eric Biggers , David Laight Cc: linux-kernel@vger.kernel.org Subject: [PATCH v3 1/5] crypto: Use memzero_explicit() for clearing state Date: Fri, 23 Oct 2020 15:21:59 -0400 Message-Id: <20201023192203.400040-2-nivedita@alum.mit.edu> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201023192203.400040-1-nivedita@alum.mit.edu> References: <20201023192203.400040-1-nivedita@alum.mit.edu> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Without the barrier_data() inside memzero_explicit(), the compiler may optimize away the state-clearing if it can tell that the state is not used afterwards. At least in lib/crypto/sha256.c:__sha256_final(), the function can get inlined into sha256(), in which case the memset is optimized away. Signed-off-by: Arvind Sankar --- arch/arm64/crypto/ghash-ce-glue.c | 2 +- arch/arm64/crypto/poly1305-glue.c | 2 +- arch/arm64/crypto/sha3-ce-glue.c | 2 +- arch/x86/crypto/poly1305_glue.c | 2 +- include/crypto/sha1_base.h | 3 ++- include/crypto/sha256_base.h | 3 ++- include/crypto/sha512_base.h | 3 ++- include/crypto/sm3_base.h | 3 ++- lib/crypto/sha256.c | 2 +- 9 files changed, 13 insertions(+), 9 deletions(-) diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c index 8536008e3e35..2427e2f3a9a1 100644 --- a/arch/arm64/crypto/ghash-ce-glue.c +++ b/arch/arm64/crypto/ghash-ce-glue.c @@ -168,7 +168,7 @@ static int ghash_final(struct shash_desc *desc, u8 *dst) put_unaligned_be64(ctx->digest[1], dst); put_unaligned_be64(ctx->digest[0], dst + 8); - *ctx = (struct ghash_desc_ctx){}; + memzero_explicit(ctx, sizeof(*ctx)); return 0; } diff --git a/arch/arm64/crypto/poly1305-glue.c b/arch/arm64/crypto/poly1305-glue.c index f33ada70c4ed..683de671741a 100644 --- a/arch/arm64/crypto/poly1305-glue.c +++ b/arch/arm64/crypto/poly1305-glue.c @@ -177,7 +177,7 @@ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst) } poly1305_emit(&dctx->h, dst, dctx->s); - *dctx = (struct poly1305_desc_ctx){}; + memzero_explicit(dctx, sizeof(*dctx)); } EXPORT_SYMBOL(poly1305_final_arch); diff --git a/arch/arm64/crypto/sha3-ce-glue.c b/arch/arm64/crypto/sha3-ce-glue.c index 9a4bbfc45f40..e5a2936f0886 100644 --- a/arch/arm64/crypto/sha3-ce-glue.c +++ b/arch/arm64/crypto/sha3-ce-glue.c @@ -94,7 +94,7 @@ static int sha3_final(struct shash_desc *desc, u8 *out) if (digest_size & 4) put_unaligned_le32(sctx->st[i], (__le32 *)digest); - *sctx = (struct sha3_state){}; + memzero_explicit(sctx, sizeof(*sctx)); return 0; } diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c index e508dbd91813..64d09520d279 100644 --- a/arch/x86/crypto/poly1305_glue.c +++ b/arch/x86/crypto/poly1305_glue.c @@ -209,7 +209,7 @@ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst) } poly1305_simd_emit(&dctx->h, dst, dctx->s); - *dctx = (struct poly1305_desc_ctx){}; + memzero_explicit(dctx, sizeof(*dctx)); } EXPORT_SYMBOL(poly1305_final_arch); diff --git a/include/crypto/sha1_base.h b/include/crypto/sha1_base.h index 20fd1f7468af..a5d6033efef7 100644 --- a/include/crypto/sha1_base.h +++ b/include/crypto/sha1_base.h @@ -12,6 +12,7 @@ #include #include #include +#include #include @@ -101,7 +102,7 @@ static inline int sha1_base_finish(struct shash_desc *desc, u8 *out) for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++) put_unaligned_be32(sctx->state[i], digest++); - *sctx = (struct sha1_state){}; + memzero_explicit(sctx, sizeof(*sctx)); return 0; } diff --git a/include/crypto/sha256_base.h b/include/crypto/sha256_base.h index 6ded110783ae..93f9fd21cc06 100644 --- a/include/crypto/sha256_base.h +++ b/include/crypto/sha256_base.h @@ -12,6 +12,7 @@ #include #include #include +#include #include @@ -105,7 +106,7 @@ static inline int sha256_base_finish(struct shash_desc *desc, u8 *out) for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32)) put_unaligned_be32(sctx->state[i], digest++); - *sctx = (struct sha256_state){}; + memzero_explicit(sctx, sizeof(*sctx)); return 0; } diff --git a/include/crypto/sha512_base.h b/include/crypto/sha512_base.h index fb19c77494dc..93ab73baa38e 100644 --- a/include/crypto/sha512_base.h +++ b/include/crypto/sha512_base.h @@ -12,6 +12,7 @@ #include #include #include +#include #include @@ -126,7 +127,7 @@ static inline int sha512_base_finish(struct shash_desc *desc, u8 *out) for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be64)) put_unaligned_be64(sctx->state[i], digest++); - *sctx = (struct sha512_state){}; + memzero_explicit(sctx, sizeof(*sctx)); return 0; } diff --git a/include/crypto/sm3_base.h b/include/crypto/sm3_base.h index 1cbf9aa1fe52..2f3a32ab97bb 100644 --- a/include/crypto/sm3_base.h +++ b/include/crypto/sm3_base.h @@ -13,6 +13,7 @@ #include #include #include +#include #include typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks); @@ -104,7 +105,7 @@ static inline int sm3_base_finish(struct shash_desc *desc, u8 *out) for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++) put_unaligned_be32(sctx->state[i], digest++); - *sctx = (struct sm3_state){}; + memzero_explicit(sctx, sizeof(*sctx)); return 0; } diff --git a/lib/crypto/sha256.c b/lib/crypto/sha256.c index 2321f6cb322f..d43bc39ab05e 100644 --- a/lib/crypto/sha256.c +++ b/lib/crypto/sha256.c @@ -265,7 +265,7 @@ static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_words) put_unaligned_be32(sctx->state[i], &dst[i]); /* Zeroize sensitive information. */ - memset(sctx, 0, sizeof(*sctx)); + memzero_explicit(sctx, sizeof(*sctx)); } void sha256_final(struct sha256_state *sctx, u8 *out)