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=-14.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL 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 2DBF6C76188 for ; Fri, 19 Jul 2019 13:37:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 043A92173B for ; Fri, 19 Jul 2019 13:37:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CFMJqLm8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729163AbfGSNhv (ORCPT ); Fri, 19 Jul 2019 09:37:51 -0400 Received: from mail-io1-f66.google.com ([209.85.166.66]:39034 "EHLO mail-io1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728715AbfGSNhv (ORCPT ); Fri, 19 Jul 2019 09:37:51 -0400 Received: by mail-io1-f66.google.com with SMTP id f4so58470448ioh.6 for ; Fri, 19 Jul 2019 06:37:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RZjbY0MaT6UAbPH1wjXD/28Vzvm/xrV41gWCDtH/Zgc=; b=CFMJqLm8STRXF20f8x5Scl80Jvrnq7e0wqiZJfZxXCAu1VhsIA7eBko5wd6eS1OEw5 Uy42PvzmsnI6FwM+axqYz7Z0vY/owPz8hNge4q2iBf83vDVxqykAPd9hYOApcMK1qBS3 uGbARDadMZv8c5LxATRua3tUulE9864iGWNLvMcWHARqCqc5JXtOY94tt9uiai/RzmeT mvA/lO4xITNKXLoA/VoHsaifsLyUiK0F5TAQIZPBhwD0JxESy+nqp34n2YIyYLQHqXKg WtDdkR5UMBB32tTcmiwCZ7NLWASFIRaCZzeVODmLvm7KNg2STC1hcyjQcXWsYgLk2Ifg Sj9g== 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=RZjbY0MaT6UAbPH1wjXD/28Vzvm/xrV41gWCDtH/Zgc=; b=SMl52YU3NP83PKM8s7YD4DVtjPkug08UeEh2Gk/CLm+W64aqVKdcTiqjK4GH0vpmBV GEZn8lJGv0Tr0APzdVQUY0zrXlEB0ZDNa8IsaUTM+XZgi/PNwCMxLtDDyT5ZySkKhZi+ 3b95mNwP2nVLxJD7Ha2JuUVJ7E/iyyUKo9T/pBArtXC4AuBaZd5V8fKTotsqpQgKb8HQ UPQoyzd7SHdKMs6E8OAyxHV9JiqOFWdsayd6cbjpYnzsKGEQOwlxZkjqSb6ltPFc1WCF UDNtFb8EdQBGxDxW8Ud1J+lsQ+7NoyOgNatNBefqXCchA45BsqI+IXfdplccCv2dvP9k spoQ== X-Gm-Message-State: APjAAAVv54IJYKsAauO4mj0yXjnP2h9cfXXprrGi6lDA3xeQ0t6+SSJT sPwtLng53VKcNkwDRjqZU8lZ8R+MZwxz96EpfUtAMA== X-Google-Smtp-Source: APXvYqyBhZpTSPfvsPmtieVyZpieljJsIsnw3wZLtW5Q7oA/SdVcTnOz10NqjvVRw9/mQWgrE57FGHsmh11BaU/x1Us= X-Received: by 2002:a5d:80d6:: with SMTP id h22mr26351958ior.231.1563543470069; Fri, 19 Jul 2019 06:37:50 -0700 (PDT) MIME-Version: 1.0 References: <20190719124329.23207-1-nh26223.lmm@gmail.com> In-Reply-To: <20190719124329.23207-1-nh26223.lmm@gmail.com> From: Dmitry Vyukov Date: Fri, 19 Jul 2019 15:37:37 +0200 Message-ID: Subject: Re: [PATCH] fs: fs_parser: avoid NULL param->string to kstrtouint To: Yin Fengwei Cc: David Howells , Greg Kroah-Hartman , linux-fsdevel , LKML , syzkaller-bugs , Miklos Szeredi , Al Viro , Thomas Gleixner , Kate Stewart Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Jul 19, 2019 at 2:44 PM Yin Fengwei wrote: > > syzbot reported general protection fault in kstrtouint: > https://lkml.org/lkml/2019/7/18/328 > > From the log, if the mount option is something like: > fd,XXXXXXXXXXXXXXXXXXXX > > The default parameter (which has NULL param->string) will be > passed to vfs_parse_fs_param. Finally, this NULL param->string > is passed to kstrtouint and trigger NULL pointer access. > > Reported-by: syzbot+398343b7c1b1b989228d@syzkaller.appspotmail.com > Fixes: 71cbb7570a9a ("vfs: Move the subtype parameter into fuse") > > Signed-off-by: Yin Fengwei > --- > fs/fs_parser.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/fs_parser.c b/fs/fs_parser.c > index d13fe7d797c2..578e6880ac67 100644 > --- a/fs/fs_parser.c > +++ b/fs/fs_parser.c > @@ -210,6 +210,10 @@ int fs_parse(struct fs_context *fc, > case fs_param_is_fd: { > switch (param->type) { > case fs_value_is_string: > + if (result->has_value) { !result->has_value ? > + goto bad_value; > + } > + > ret = kstrtouint(param->string, 0, &result->uint_32); > break; > case fs_value_is_file: > -- > 2.17.1 > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20190719124329.23207-1-nh26223.lmm%40gmail.com.