From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx48HyvUVTJba5PcJBfJbbpC9jT2IDPyFwGw9nBLmKoYXEm9GZ9sEmmz7SJji47O6EJJITy8e ARC-Seal: i=1; a=rsa-sha256; t=1523282144; cv=none; d=google.com; s=arc-20160816; b=gnY7vOzcj423TrJTEDSxA9ybxErS+BHxrdMS9rQSulq607UJ93xt4G3gUXRfYTy4kC 4ZIBgN0z3UIbu0KHAfF2srK5tsv52THUioUEbtRRGv21iLxmVXcLu+p9y0O+GbSRW930 IWSk+P/4u1AP9clCemipTw2Xb3VDARAKzhefKrhO3pVZg+pWI06CdEuo07BFhLhuIaHF hQBbU/k/BfiI6o1HKfAiiQZ7aynjk4G9a660XnZP7hO9azf+43iRpiI0lsu8c+w5sIgn IYqkbWCZg69i9hexW7dYps5OHPjqLYFu507iPuLWUukpfdRdWYodtCPDV2zMsDiFOr+5 WPzA== 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=bvfZVgukrG4Uz/3K/kgiuiCeoBiYKZFn3z8Tr50BqHA=; b=n3sFMfwkY+mpOS7RsVxFYcnCuHGOm0rZL+IPOqld+eE2sRaUWeSCPmJx910iklfwQx 9p+MhpyMNi3rp3LdyPcyOOxc09gqoe+CVGMvg6jfucZ2a6xoMltwjM7BiCZmXO2z0jf+ 9chlcppwjrh0/bhHVnV4qqbGCTfwCPAskqyIhY3Y9JiCv50wRpsOUCCAWLUgDHPvpFhO dn5D3Ya9eVRd6FVGV4ZhjRFfqSlCWqG4zooe3NcCcuXxaHuTvQWs/y6HLfRICCmbUsZm a0viAw/DWgh4Zkxup06Q+6hazIiOhLcf00GI/UNwu7ZVIRxQ7S1haBeQ63cJ9+75PNp+ ZOKA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=aCA0tdrK; spf=pass (google.com: domain of kernel-hardening-return-12923-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12923-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=aCA0tdrK; spf=pass (google.com: domain of kernel-hardening-return-12923-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12923-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 5/6] crypto: cts - avoid VLA use Date: Mon, 9 Apr 2018 15:54:03 +0200 Message-Id: <1523282044-22075-6-git-send-email-s.mesoraca16@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1523282044-22075-1-git-send-email-s.mesoraca16@gmail.com> References: <1523282044-22075-1-git-send-email-s.mesoraca16@gmail.com> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597277098191964143?= X-GMAIL-MSGID: =?utf-8?q?1597277098191964143?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: We avoid 2 VLAs[1] by always allocating MAX_BLOCKSIZE*2 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/cts.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/crypto/cts.c b/crypto/cts.c index 4773c18..12e6bd3 100644 --- a/crypto/cts.c +++ b/crypto/cts.c @@ -50,6 +50,7 @@ #include #include #include +#include "internal.h" struct crypto_cts_ctx { struct crypto_skcipher *child; @@ -104,7 +105,7 @@ static int cts_cbc_encrypt(struct skcipher_request *req) struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); - u8 d[bsize * 2] __aligned(__alignof__(u32)); + u8 d[MAX_BLOCKSIZE * 2] __aligned(__alignof__(u32)); struct scatterlist *sg; unsigned int offset; int lastn; @@ -183,7 +184,7 @@ static int cts_cbc_decrypt(struct skcipher_request *req) struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); - u8 d[bsize * 2] __aligned(__alignof__(u32)); + u8 d[MAX_BLOCKSIZE * 2] __aligned(__alignof__(u32)); struct scatterlist *sg; unsigned int offset; u8 *space; @@ -359,6 +360,9 @@ static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb) if (crypto_skcipher_alg_ivsize(alg) != alg->base.cra_blocksize) goto err_drop_spawn; + if (alg->base.cra_blocksize > MAX_BLOCKSIZE) + goto err_drop_spawn; + if (strncmp(alg->base.cra_name, "cbc(", 4)) goto err_drop_spawn; -- 1.9.1