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=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 76482C28CC3 for ; Fri, 31 May 2019 15:55:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BF4626B9A for ; Fri, 31 May 2019 15:55:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=paul-moore-com.20150623.gappssmtp.com header.i=@paul-moore-com.20150623.gappssmtp.com header.b="RPZh76mo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727056AbfEaPzk (ORCPT ); Fri, 31 May 2019 11:55:40 -0400 Received: from mail-lj1-f194.google.com ([209.85.208.194]:41091 "EHLO mail-lj1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727034AbfEaPzg (ORCPT ); Fri, 31 May 2019 11:55:36 -0400 Received: by mail-lj1-f194.google.com with SMTP id q16so10096875ljj.8 for ; Fri, 31 May 2019 08:55:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RVcOaYatOpeo1CRV+hYtc16/sImBcgmxdJUqU74IXf0=; b=RPZh76moKr55vlOhT6KnMQNS2x36jsAOlxZc9yNKyxBw0/CnSaJqQXxPo8wQogqSrH xvmcd8R/2F0tPP/2ihZ1+29FSCm9nEmo6aw5HY8bzked4RIQPKJuQOkb+A/GhtgtIj5a aLWdXP2tDDewNDPoZfQNbPfPMJRAtol/Hsyp/gqT51L1Anjn5GoDMPRjuY6Sc09LcwlO n4vSZg3ld4ZHB+BWhlysxicuNc0AlznR6JfJ4CZMe6EOFOQnF/TJRQYeJKzSXA7tqj9a Jpm9h6pr7EN7xwZSsvAaiJ12eb5JuE2TSUY+75Sh0GRQZQCe1qpwgP9inI/9WD2YWaC2 8PbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RVcOaYatOpeo1CRV+hYtc16/sImBcgmxdJUqU74IXf0=; b=WPIeSVOTX3g6IwUPARyIPQnhPlFA/06SyEJRUMcc3Noyu6ofoA/JVp+bc1+Akp3lHc kZH38sNV1NqdMS7WtvK2hUCSpfFk9i6xloDw6yjuDOwgVsHZzxVtK6U5qZMt7RmTTDkv vmH9btl24c6pCD1zb4k2vqIuaArR5EP14v/e9X5/eAErjkvNeEdvcwPQGcKj16VMp/wf c+WMhnmMcXpFg00FiVFlcEPwrExzNDvEZF9hdhRUjms0KwiN49VEE8KkcEmWOnrmHduX et0/5HkrGBIHNkZXYUFCm1C/VVvDA3s/QSpWFR0/uAdqVStvm6RjdDPfHgaT4uLvJZ6H qx6Q== X-Gm-Message-State: APjAAAV30EXV2oI+r1UPwUw4itNIijTiSp+uENu/2K8dk1BNyzjOPlWN 5AH14YfFxhSHZJt8+WYCVzDD5Ko29ARINoPKgHZd X-Google-Smtp-Source: APXvYqzr2MCUTgiueRQHjiAeFx7vxTXPmGHbdykoMlbeOPTpRuJBL1Ru1ZFTbbOjFttwWXo6DFPAaxt9JHVyrRBUZds= X-Received: by 2002:a2e:9a97:: with SMTP id p23mr6347647lji.160.1559318134012; Fri, 31 May 2019 08:55:34 -0700 (PDT) MIME-Version: 1.0 References: <20190530080602.GA3600@zhanggen-UX430UQ> <20190530085438.GA2862@zhanggen-UX430UQ> In-Reply-To: <20190530085438.GA2862@zhanggen-UX430UQ> From: Paul Moore Date: Fri, 31 May 2019 11:55:23 -0400 Message-ID: Subject: Re: [PATCH v2] hooks: fix a missing-check bug in selinux_add_mnt_opt() To: Gen Zhang Cc: Ondrej Mosnacek , Stephen Smalley , Eric Paris , ccross@android.com, selinux@vger.kernel.org, Linux kernel mailing list , netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 30, 2019 at 4:55 AM Gen Zhang wrote: > > In selinux_add_mnt_opt(), 'val' is allcoted by kmemdup_nul(). It returns > NULL when fails. So 'val' should be checked. > > Signed-off-by: Gen Zhang > Fixes: 757cbe597fe8 ("LSM: new method: ->sb_add_mnt_opt()") Previous comments regarding "selinux:" instead of "hooks:" apply here as well. > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 3ec702c..4797c63 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -1052,8 +1052,11 @@ static int selinux_add_mnt_opt(const char *option, const char *val, int len, > if (token == Opt_error) > return -EINVAL; > > - if (token != Opt_seclabel) > - val = kmemdup_nul(val, len, GFP_KERNEL); > + if (token != Opt_seclabel) { > + val = kmemdup_nul(val, len, GFP_KERNEL); > + if (!val) > + return -ENOMEM; It looks like this code is only ever called by NFS, which will eventually clean up mnt_opts via security_free_mnt_opts(), but since the selinux_add_opt() error handler below cleans up mnt_opts it might be safer to do the same here in case this function is called multiple times to add multiple options. > + } > rc = selinux_add_opt(token, val, mnt_opts); > if (unlikely(rc)) { > kfree(val); -- paul moore www.paul-moore.com