From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49yXcG9PFfZA5aOrleFox5Cnp6XhvMBia7fouuPMcc3TsM3gP6Iv21M7/KBFxvNlCvbPBk1 ARC-Seal: i=1; a=rsa-sha256; t=1523126399; cv=none; d=google.com; s=arc-20160816; b=NZHlK+L/uOeQlZp5F9l6m6b2Q3+vYj5XucQ6Gyr1fSeydCFjME8O3hX6NVUi7ArB/i 3P4LA4Q0wOgWZIc5mcqPFJERt3vOuF7iEKPFSYD9JaorB0v/7r+iRHKqUQ0EO6gw9z7j vDxi5Vib4GqlpTY9lLwWUvQFFlq/IB1upVbpG1GZ46oRkiZNIQmApRmr9zj8xfufk9pl 1JIj1ipJT0WZaNu0HzD4ObYo55Z/eEQXotSOpFKm73C2KP2FJoCd6y5UYwrU0WAxOlvT 5wAutrZ+Xb5siWIvqbc+Vq702cgeBzuaG9DkY4EDK7tCXJQut+KYLDecEZ+gJJ+jkoFY V3CA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:delivered-to:list-id:list-subscribe:list-unsubscribe :list-help:list-post:precedence:mailing-list :arc-authentication-results; bh=otcFk/LhYCI6+Eka1h1DNCCDW9Ubad/bpWI6UKakoZM=; b=DbSDX4c9yXxbDWWkt9kzgI3BK1iIgQc3bFdqx3nkwOTyJr/LMhmphYWMpjpNHPi0YL TE8LskKiT+BK7GCzB6fWblGDFXE2iKJs4v0THei6BFHvoRMYsBqz7/HJVBgMW1ErFncx GXSrZRL/f9HdqmXa/2V7Ssy3gj3MpnQaMBjzdpaFp8iBP+cLtca0NHk7A/R6ehdFwdKn 6fOYRRXWPEWbCryAUclGIV0dMARPiqD9aV5bwImTWynXCVEPJHPHP1NwQvvVOPTFhfic BUuw482eyESr6lxb5899ZK1YaJPNAYfwcStB79ii2KHLWroS7K5bomfkULW+X4j+YfCQ 4cJw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=IF08NNkU; spf=pass (google.com: domain of kernel-hardening-return-12880-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12880-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=IF08NNkU; spf=pass (google.com: domain of kernel-hardening-return-12880-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12880-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: 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 4/6] crypto: pcbc - avoid VLA use Date: Sat, 7 Apr 2018 20:38:21 +0200 Message-Id: <1523126303-23205-5-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> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597113787790138764?= X-GMAIL-MSGID: =?utf-8?q?1597113787790138764?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: We avoid 2 VLAs[1] by always allocating MAX_BLOCKSIZE bytes. We also check the selected cipher at instance creation time, if it doesn't comply with these limits, the creation will fail. [1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Salvatore Mesoraca --- crypto/pcbc.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/crypto/pcbc.c b/crypto/pcbc.c index d9e45a9..797da2f 100644 --- a/crypto/pcbc.c +++ b/crypto/pcbc.c @@ -21,6 +21,7 @@ #include #include #include +#include "internal.h" struct crypto_pcbc_ctx { struct crypto_cipher *child; @@ -72,7 +73,7 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req, unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; u8 *iv = walk->iv; - u8 tmpbuf[bsize]; + u8 tmpbuf[MAX_BLOCKSIZE]; do { memcpy(tmpbuf, src, bsize); @@ -144,7 +145,7 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req, unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; u8 *iv = walk->iv; - u8 tmpbuf[bsize] __aligned(__alignof__(u32)); + u8 tmpbuf[MAX_BLOCKSIZE] __aligned(__alignof__(u32)); do { memcpy(tmpbuf, src, bsize); @@ -251,6 +252,10 @@ static int crypto_pcbc_create(struct crypto_template *tmpl, struct rtattr **tb) if (err) goto err_drop_spawn; + err = -EINVAL; + if (alg->cra_blocksize > MAX_BLOCKSIZE) + goto err_drop_spawn; + inst->alg.base.cra_flags = alg->cra_flags & CRYPTO_ALG_INTERNAL; inst->alg.base.cra_priority = alg->cra_priority; inst->alg.base.cra_blocksize = alg->cra_blocksize; -- 1.9.1