From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68513C433EF for ; Tue, 1 Feb 2022 19:07:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242300AbiBATHE (ORCPT ); Tue, 1 Feb 2022 14:07:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232024AbiBATHD (ORCPT ); Tue, 1 Feb 2022 14:07:03 -0500 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C104C061714 for ; Tue, 1 Feb 2022 11:07:03 -0800 (PST) Received: by mail-pf1-x432.google.com with SMTP id a8so16699542pfa.6 for ; Tue, 01 Feb 2022 11:07:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=vWJtc/jz3NoYF9uCthXFk67SqjsIB7RJSbGEFvTN/iM=; b=iSJDkJ5OdDeFbxyOzdLekrR3/0rd6TUS2SxZz0WxjzfyJ94UgxhHoPvQJpGVCTtcdH s4biQFpPJRStBBHkAjwh/5vF6XXyRe8YFOtvSRhYOwfsQLjsntoTM4O+MnVZSkzSnVWt UKB2j9qLI0kmTsN3HaBBD0AO7GEeyk79bF/ko= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=vWJtc/jz3NoYF9uCthXFk67SqjsIB7RJSbGEFvTN/iM=; b=J2HWaMwhZO6UoKyTBT+BQDqf31OiSn2jdSaLHtWhGCWc8e3N5e9ScsWkapGJQb8eKS hrPddAkDe5QQ3PZc8B56YNwyU0tQZd727dWcK4uaq2a2Tsv/NZ3AxICn5GcFZKdg+kp1 rsUqvaIKJxLqLW/MVir+lB4UJHZ8QMtnhrrkGh2iv/vRqSdIaoWLODpkTeMcYPZbtiFL 3plxEh0HqxzS4lGupWcOGRouDjFFR9rqcpH23cp/Q3s8h1ydRwGESCpBo8js2WOAYlhP D8ZF2PmAuD76SGpYp1IGXmiMbiv1jRzLs5QyiiCY8bKL5A7uJw5Jt7biRgfUJzZTIfkz 5uGA== X-Gm-Message-State: AOAM530hQUh4uV2f6BIT1yxT0g73SWNnXE0LVJuVclx114q2Lm2o9e4t 9sdRRanlXoQnMzRVocGwlKy35w== X-Google-Smtp-Source: ABdhPJzi1szkx68ooZCj+rN//sH6e7I3nmqujxk9Bk4xfgJGsNuh6IWI1ON2C8vwZ1OHES4iTJHhoA== X-Received: by 2002:a63:496:: with SMTP id 144mr22280682pge.380.1643742422709; Tue, 01 Feb 2022 11:07:02 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id 30sm393263pgq.39.2022.02.01.11.07.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Feb 2022 11:07:02 -0800 (PST) From: Kees Cook To: Andrew Morton Cc: Kees Cook , Ariadne Conill , Michael Kerrisk , Matthew Wilcox , Christian Brauner , Rich Felker , Eric Biederman , Alexander Viro , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] exec: Fix min/max typo in stack space calculation Date: Tue, 1 Feb 2022 11:07:00 -0800 Message-Id: <20220201190700.3147041-1-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=893; h=from:subject; bh=AyfN0zm5xZ0Db6oIPqup3ab4ouMbc0RRClkxyP2qBeg=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBh+YTTKrxw/Oaf72PaFCDQWBpcuw+xIFQ/0i2ikcAr 2xFRrmCJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYfmE0wAKCRCJcvTf3G3AJhseD/ 9zYuF7jyAPi2L0v81MP3RDf7VIrJ4xgGyoaLiTYxpwk+qOAW9CkBkCV9WopgBo1vMsSCOfN+W2RLnO Pimv6mvRjgSDzwChg9PLzh42NrShTKqoPtkkdjHvVDJ2wOzwcIGcv6qP1KuvRw4ay3slqiVYTt4zPv Mt6H4rml8ElelCkMo1WiqbAugm2gcwOuLxXfEAPCQxTCSz5ajAUH7n/Iqgolu5wzKQP6uRDx/j4y/r rXLERVtMJBcmAVab+49RBXKRmpwcAIv5yYXZQaqEzlt872qcf3UijCEse7hN08365czgY4gpoX5+7P mEjRbZRG+HIU4oupbKJoPgrSIILQxJCID9/7L4L/KtDCs7ENGw27QFtuCI2X6ArtGhFPNvaIbYsU8P CkLa0JmjY1MPJulCQWS8Y6MhrPAc7Sk+VNH/tTrIoSDY+5DwKFczRXckh6jERSLUdAX5aaHTyX/nFk Tb2kLrgqwus7rdlx62zYCGPdJ+nyhGb5W01UVRY9VsrorM/mkOQDqoClWlfmDKirHE4lyEdoHHO4z4 Pz1H4fLS9psYmGX4VjQE0gUJfRTt1qogXkvsTO5TnuhCP91I6jGXl4JFJPRxBA/Gkgh8dpOTpfMgoT fn5FGSVh2Zq+SDEVeK0URl2AKzSH5vsa8I7fi4SspI/OLR0oxOYaAwnGqHFA== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org When handling the argc == 0 case, the stack space calculation should be using max() not min(). Signed-off-by: Kees Cook --- This is a fix for exec-force-single-empty-string-when-argv-is-empty.patch https://lore.kernel.org/mm-commits/20220201004100.BF6D6C340E8@smtp.kernel.org/ --- fs/exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/exec.c b/fs/exec.c index bbf3aadf7ce1..40b1008fb0f7 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -502,7 +502,7 @@ static int bprm_stack_limits(struct linux_binprm *bprm) * argc can never be 0, to keep them from walking envp by accident. * See do_execveat_common(). */ - ptr_size = (min(bprm->argc, 1) + bprm->envc) * sizeof(void *); + ptr_size = (max(bprm->argc, 1) + bprm->envc) * sizeof(void *); if (limit <= ptr_size) return -E2BIG; limit -= ptr_size; -- 2.30.2