From patchwork Tue Jul 2 00:01:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cfir Cohen X-Patchwork-Id: 11026947 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 00F621398 for ; Tue, 2 Jul 2019 00:02:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DF76D2874B for ; Tue, 2 Jul 2019 00:02:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D31DC28756; Tue, 2 Jul 2019 00:02:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7BDD32874B for ; Tue, 2 Jul 2019 00:02:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726977AbfGBAC1 (ORCPT ); Mon, 1 Jul 2019 20:02:27 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:33611 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726866AbfGBAC1 (ORCPT ); Mon, 1 Jul 2019 20:02:27 -0400 Received: by mail-qt1-f202.google.com with SMTP id y19so14926603qtm.0 for ; Mon, 01 Jul 2019 17:02:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=14MOM6ICngoLLgb1hrf/bM8O+6Uy5LcBnEPwLhZGisA=; b=ab0ZyOF0ZZkkQMOBm16TGGEeQFK/jjtvGf3wEx27RMnXQxrDBNdaJYXoBBeGr5LnO2 yCn6V8eE+fGZvJcjh8XYGMVFt8fgkv2h31llQxIwD0pszH2nCXpm4pmE/yAxWGiqducr Um/F4GZ5f+4xXzJnSDUyhYRr75CeDapfZf+W+E6QIIIEcvN/2bmVLsbnDVtTg92I11bF Xvi2CyLVmX4o/fXUISIVyJFG0yhus80Kd98bDgXNFc08pLguDIzHn40en5csghrqJdP/ CoVBUT6A1KZCzgFSRU9yuIebcKq6qj/wydhx0jBqZEIurcaCWB5wcib9YZTFizzNAgmw Kt3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=14MOM6ICngoLLgb1hrf/bM8O+6Uy5LcBnEPwLhZGisA=; b=bZUJ+DEie+178EtgVfCYGv6+/pF42JmqZGl2BGFGd6uGC4eIol9igXclQqlpo1rOsp b23dA+x9eBl6MzLYPoMz7Aq7re5ZKQ0PBuD+++c6JeDiT+Gm+ZN9EU3Op2RuyZpSVlDG TSK4CNDVu6bPNPKQj1uGa6iFdb0UjmrEFuOn5R7scrFlHRx7wGlDpCgUUcAvs3g8SYj+ PAH0ZBfyedjvfMfIqK80O3aHDoZt3puFkJ26gVBQIdC1BiRPS+9awU0GLozIxM+rvZ23 s4eOCzUHvfZyN0vSFa0TYcCTQkAvxMcdtN7CwHZLTHHndNJS2i/OdPt6rAj65SwPI/89 D4Zg== X-Gm-Message-State: APjAAAUv+VeKQY3ChKJqeKiyJ0XuOtnkFuFnTVuXOFBc2NnVzWVaBCKJ 3oSI44BVn0Ij7Tm4JYFn8PULA7Yi X-Google-Smtp-Source: APXvYqxrjtJzzGyzen9dN3F04N0Z8Svgc4wGjY+W5ZyOubaozgAQD8lN8zC3uAhG2jkMQE/hKlKPNVyS X-Received: by 2002:aed:38c2:: with SMTP id k60mr21843273qte.83.1562025746390; Mon, 01 Jul 2019 17:02:26 -0700 (PDT) Date: Mon, 1 Jul 2019 17:01:32 -0700 Message-Id: <20190702000132.88836-1-cfir@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH] crypto: ccp/gcm - use const time tag comparison. From: Cfir Cohen To: Tom Lendacky , Gary Hook , Herbert Xu , David Rientjes Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, Cfir Cohen Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Avoid leaking GCM tag through timing side channel. Signed-off-by: Cfir Cohen --- drivers/crypto/ccp/ccp-ops.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c index db8de89d990f..633670220f6c 100644 --- a/drivers/crypto/ccp/ccp-ops.c +++ b/drivers/crypto/ccp/ccp-ops.c @@ -840,7 +840,8 @@ static int ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q, if (ret) goto e_tag; - ret = memcmp(tag.address, final_wa.address, AES_BLOCK_SIZE); + ret = crypto_memneq(tag.address, final_wa.address, + AES_BLOCK_SIZE) ? -EBADMSG : 0; ccp_dm_free(&tag); }