From patchwork Sat Apr 7 18:38:20 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Salvatore Mesoraca X-Patchwork-Id: 10327995 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.web.codeaurora.org (Postfix) with ESMTP id B9A316020F for ; Sat, 7 Apr 2018 18:39:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ABD24294D5 for ; Sat, 7 Apr 2018 18:39:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9EC7B294E1; Sat, 7 Apr 2018 18:39:39 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable 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 5275A294D5 for ; Sat, 7 Apr 2018 18:39:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752272AbeDGSin (ORCPT ); Sat, 7 Apr 2018 14:38:43 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36712 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752255AbeDGSil (ORCPT ); Sat, 7 Apr 2018 14:38:41 -0400 Received: by mail-wm0-f65.google.com with SMTP id x82so8430102wmg.1; Sat, 07 Apr 2018 11:38:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=YAlTGdnPdSsRn+04SbOD45FkZFw5nVfUTH5BnaTOpDI=; b=fQbxwYCQRwguXt0Nu40/mZ5/B67a2rWGwzf3U9rFLld0sJH1wO/aywLd910gm7v4DF ExjNqLVoklVkkqDfHshlft6EKkAK1wtzkF1LXPGgEe2P+EsQ0+oEXvpGm43abJ7hAN8H oMCBUdJVNKeqz+2PHoIAM/U2b8slQ/ZsrXgvYAXTAEhoCVDBTWN8kyosUwaPJDia7oki upO0WOq+CiVKMMz/B1fgtDWz2oHjYAY58uU4SQUn0VCNIjhEglSVERPElKo7cQiIqwZC WfjDGZPA120unW7ENN6a66czCj1LE2zgXCtKIyLLC0G+ByORC5SMoFNqVJmHxVARsJ1j wDFw== 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; bh=YAlTGdnPdSsRn+04SbOD45FkZFw5nVfUTH5BnaTOpDI=; b=mp/fGU/pmrggIKtSAgZMT19I/hMmiVqb/Zqwy72RzsR9O+j7IjHAs7DqVuGWIBlG3d yHZiKBa8HxaakEVBMWI+hddjMZ3cZXY+oPb3QeiFxCriK/pDj+Ijb41I7sNUh7e/KgEb 7fbb4JcM0bL4eAUE99q6zigaPK10G9A+Sh4TuRbvv4e7IPqCDjqxdlce/5V1OQ1zbi+U IBJZWgEZAUlgctef6pvhgXmqM0pDxUtEw3HXzK0BD6SWyAm1hxHNxN76RK9FK329cxER vHtA1o+HjCwhkWzk5MUzUgdiWpyh+kiLKMVZqNduMe8Yhv9UC4Vun5o2A5STneHQ/YmG pNNw== X-Gm-Message-State: ALQs6tAVx6NFff6xGbHT017Kjw7vhZLj5WLz1sjXZgxb8T3kdDj4z6my TCDroEyy6IaiBOaIDtRHY+ZjMUecsqY= X-Google-Smtp-Source: AIpwx49Z64EOPvvkM0YfCg+Fmzo6IQFUgYlKoPIuIpANWRVNsL7dWi4r3Uc2yKDTay0PNEa2eHE7bw== X-Received: by 10.28.21.84 with SMTP id 81mr740331wmv.36.1523126320413; Sat, 07 Apr 2018 11:38:40 -0700 (PDT) Received: from localhost ([31.159.162.22]) by smtp.gmail.com with ESMTPSA id m184sm7135034wme.15.2018.04.07.11.38.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sat, 07 Apr 2018 11:38:40 -0700 (PDT) From: Salvatore Mesoraca To: linux-kernel@vger.kernel.org Cc: kernel-hardening@lists.openwall.com, linux-crypto@vger.kernel.org, "David S. Miller" , Herbert Xu , Kees Cook , Salvatore Mesoraca , Eric Biggers , Laura Abbott Subject: [PATCH 3/6] crypto: api - avoid VLA use Date: Sat, 7 Apr 2018 20:38:20 +0200 Message-Id: <1523126303-23205-4-git-send-email-s.mesoraca16@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1523126303-23205-1-git-send-email-s.mesoraca16@gmail.com> References: <1523126303-23205-1-git-send-email-s.mesoraca16@gmail.com> 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 We avoid a VLA[1] by always allocating MAX_BLOCKSIZE + MAX_ALIGNMASK bytes. We also check the selected cipher at initialization time, if it doesn't comply with these limits, the initialization will fail. [1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Salvatore Mesoraca --- crypto/cipher.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/crypto/cipher.c b/crypto/cipher.c index 94fa355..9cedf23 100644 --- a/crypto/cipher.c +++ b/crypto/cipher.c @@ -67,7 +67,7 @@ static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *, { unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); unsigned int size = crypto_tfm_alg_blocksize(tfm); - u8 buffer[size + alignmask]; + u8 buffer[MAX_BLOCKSIZE + MAX_ALIGNMASK]; u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); memcpy(tmp, src, size); @@ -105,9 +105,14 @@ static void cipher_decrypt_unaligned(struct crypto_tfm *tfm, int crypto_init_cipher_ops(struct crypto_tfm *tfm) { + const unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); + const unsigned int size = crypto_tfm_alg_blocksize(tfm); struct cipher_tfm *ops = &tfm->crt_cipher; struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; + if (size > MAX_BLOCKSIZE || alignmask > MAX_ALIGNMASK) + return -EINVAL; + ops->cit_setkey = setkey; ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ? cipher_encrypt_unaligned : cipher->cia_encrypt;