From patchwork Fri Jul 19 12:43:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yin Fengwei X-Patchwork-Id: 11050055 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 33EBF14F6 for ; Fri, 19 Jul 2019 12:44:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2093A2886F for ; Fri, 19 Jul 2019 12:44:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1007928868; Fri, 19 Jul 2019 12:44:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8F35B28868 for ; Fri, 19 Jul 2019 12:44:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728204AbfGSMn6 (ORCPT ); Fri, 19 Jul 2019 08:43:58 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:35923 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727559AbfGSMn5 (ORCPT ); Fri, 19 Jul 2019 08:43:57 -0400 Received: by mail-pl1-f194.google.com with SMTP id k8so15602861plt.3; Fri, 19 Jul 2019 05:43:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id; bh=/FrjOlHsU/rFl8swGWw38s2HqBJIeif3GsejqegBQfE=; b=HHBrAYBsAlGxR2OIsZGbdNPvlEtFEwW5mIo9kKXWBwu9d4V+76wWe/JhlvzH4cRzOl c/s+PKUjJ768Dms1tPcHbfJ6sR5hRwsWPCSn8eY//T6P67/wyUyJaHOjg8oWvu6deR80 iW23s6joLdSePWwcOSjbrhX1eeq5YlkoYEL1u0MnizWv1QX8dyQ5a6CyDaZEgcw8W0+U jgChwcXrQzqkbJ1aqtVcnbz5FjkgVGMUeVC5uv7X+KyxzAUgwiPOaljKG3L/1HPYtvsO 3Tt5t9tvTQBjVupL7CxLf8z4FpRe2usC6RXP0cnB3bESqEweUF6MwX50Ouw7y5Q2oi/W vGnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id; bh=/FrjOlHsU/rFl8swGWw38s2HqBJIeif3GsejqegBQfE=; b=E6xfx0dbhMiZ4VD86urN/fjQT8a10D+JviPPhaRKIYJB1i7mekielgjMHQpkp6BEoH /SoHo4KbbNefYiX1biH5aqw23h+94kCoK2QJXzX9RytH10ftK7AfxDFTWBgNoM01UVY3 LI6sa/vJ+UlcHx+dFvA2DG8D3oLOc3wd2NXrj6REyaljn0yq+FR+39nFeqYkIl9tdvDd OwVnKiPj+eXqzmXalU/+q6JZt2+xw7m9GWvQVe2drxf0q7jgD2k5yOkBONLN8kP8ftFu wsyrTSiKf3TMh9LOl/DNreuBzMpfQe/Lb4bPyATICbyk0Kxb9afJOSH2+dmXPPnJYlmE /HnQ== X-Gm-Message-State: APjAAAXYgD81q2RvWr5A8X8pyg8pHRuf/wQpxBR/ECSwUR6404uuOcVQ DLQyBUyK2GumBZs0A7zX7Ck= X-Google-Smtp-Source: APXvYqx+9N9T2/+1wzwWwh/y89oJ9P0IE/G4zN8NafEAO+fPvr12z2A57s7nZTYhogOgeMC5M9ukpg== X-Received: by 2002:a17:902:724c:: with SMTP id c12mr55789189pll.219.1563540237303; Fri, 19 Jul 2019 05:43:57 -0700 (PDT) Received: from localhost.localdomain ([103.121.208.202]) by smtp.gmail.com with ESMTPSA id l189sm37612530pfl.7.2019.07.19.05.43.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 19 Jul 2019 05:43:56 -0700 (PDT) From: Yin Fengwei To: dhowells@redhat.com, gregkh@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, miklos@szeredi.hu, viro@zeniv.linux.org.uk, tglx@linutronix.de, kstewart@linuxfoundation.org Subject: [PATCH] fs: fs_parser: avoid NULL param->string to kstrtouint Date: Fri, 19 Jul 2019 20:43:29 +0800 Message-Id: <20190719124329.23207-1-nh26223.lmm@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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) { + goto bad_value; + } + ret = kstrtouint(param->string, 0, &result->uint_32); break; case fs_value_is_file: