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 X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BE63C43331 for ; Mon, 22 Feb 2021 15:17:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7C966148E for ; Mon, 22 Feb 2021 15:17:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231329AbhBVPRG (ORCPT ); Mon, 22 Feb 2021 10:17:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231240AbhBVPNz (ORCPT ); Mon, 22 Feb 2021 10:13:55 -0500 Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD2C8C061797 for ; Mon, 22 Feb 2021 07:12:49 -0800 (PST) Received: by mail-wm1-x330.google.com with SMTP id x16so13834961wmk.3 for ; Mon, 22 Feb 2021 07:12:49 -0800 (PST) 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 :mime-version:content-transfer-encoding; bh=S1lCywCtYVxEsnuw6UX2uJMQ5VyTPpsEmxTnLQJHs4w=; b=rWf86sGXPcNotlzO6S3Y7LO5Nm2WfrkvTP72KQo9Y1VVv5HcanSJASCmDSQC/FvS4l 4X+BnIYovgNuWrjBcRMMgByxaJJKo+WuEdB5B4TeeH5KAB/k0o74OaToO8dP5U+NeEuv kjZevojzhOKXgUYIqK4jZ7+a8FFI4fyWPiYx976xmPlhyZGLbZFjCJRnjHuPAx0agih+ CBwler96z49x42STZP1ftWGwflDrYvL5xmIdJrvmSrGhRlJ+bHCMVys2WE6akJcWlLDD pN58SYbZPSp/1g7GyQVoqT/QQavBz69bDTBxGFZjGXmlE5vLK087Q62L8G+gsKUJ9TPk vUPQ== 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:mime-version:content-transfer-encoding; bh=S1lCywCtYVxEsnuw6UX2uJMQ5VyTPpsEmxTnLQJHs4w=; b=AYv1oU44E+0qzSClGvqXgW8drLk8a+bArYxkBrqbf/o3lLzqVFEK7D5jQmXhg8/FZM vr0vleq1Ig7sghyECCg1z9rmzeqEncQWrXuYlgNZ07wgS8+KPDhtJjeGoDjFw3FyRboI FED+2DErA46OpSRPIu2JoBrkYo9kVaVbSMjdLmgn23ZnWTtm/eBe2W/9P4LeQxucAHCy fqmcFhFcrEWrgRUxRsuHCaASHDy9f4aq2WTBiUK4RYMweugj5qhZ+/yWgejEYFOM6/C4 7hSEKGLDzqoHxjyPszZEy2Tp/z6oSB2Qc9RZb0Da6w2Fdq9ENwB41+fAWjnNOcTDxQ0u E6vA== X-Gm-Message-State: AOAM531fYieLqI28fm/8+d9KuFW1I2XPs0fpj19sit+ryPIdiMvCPbxz F8ZmIryUDQ42feh690uHAS9CyDvRpAnoJM+Bg78= X-Google-Smtp-Source: ABdhPJxdv2k+gVDTX8PjxaPQz6UiDFMRMwv8LZF9w+l6PKqIasSjklSPneGhJPBCNfwEJDSzCT51jg== X-Received: by 2002:a7b:c14d:: with SMTP id z13mr14117614wmi.6.1614006768018; Mon, 22 Feb 2021 07:12:48 -0800 (PST) Received: from debby (176-141-241-253.abo.bbox.fr. [176.141.241.253]) by smtp.gmail.com with ESMTPSA id m17sm24783581wmq.5.2021.02.22.07.12.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Feb 2021 07:12:47 -0800 (PST) From: Romain Perier To: Kees Cook , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman Cc: Romain Perier , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org Subject: [PATCH 05/20] kobject: Manual replacement of the deprecated strlcpy() with return values Date: Mon, 22 Feb 2021 16:12:16 +0100 Message-Id: <20210222151231.22572-6-romain.perier@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210222151231.22572-1-romain.perier@gmail.com> References: <20210222151231.22572-1-romain.perier@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The strlcpy() reads the entire source buffer first, it is dangerous if the source buffer lenght is unbounded or possibility non NULL-terminated. It can lead to linear read overflows, crashes, etc... As recommended in the deprecated interfaces [1], it should be replaced by strscpy. This commit replaces all calls to strlcpy that handle the return values by the corresponding strscpy calls with new handling of the return values (as it is quite different between the two functions). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy Signed-off-by: Romain Perier --- lib/kobject_uevent.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 7998affa45d4..9dca89b76a22 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -251,11 +251,11 @@ static int kobj_usermode_filter(struct kobject *kobj) static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem) { - int len; + ssize_t len; - len = strlcpy(&env->buf[env->buflen], subsystem, + len = strscpy(&env->buf[env->buflen], subsystem, sizeof(env->buf) - env->buflen); - if (len >= (sizeof(env->buf) - env->buflen)) { + if (len == -E2BIG) { WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n"); return -ENOMEM; }