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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 DC292C7618F for ; Fri, 19 Jul 2019 23:30:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD1D821849 for ; Fri, 19 Jul 2019 23:30:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="VvYPxMG7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732878AbfGSXaQ (ORCPT ); Fri, 19 Jul 2019 19:30:16 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:43130 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728909AbfGSXaQ (ORCPT ); Fri, 19 Jul 2019 19:30:16 -0400 Received: by mail-pf1-f194.google.com with SMTP id i189so14799664pfg.10; Fri, 19 Jul 2019 16:30:15 -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=66rTuFgUuVjzdvwr5vssBmJQ5naQ4mmWCVou0nSVcyk=; b=VvYPxMG7i8Or1RYsycw7x+7Nzy9pylALB6piQ4ROpqGWdyyYPZkQfdlP0kvlmlw/Fy HtaSHcZ3k39vSEu3N3s/cl4CcYdSzGd0XOZHMLi9VzjxgCJMqB4nSSSIFK9YC1dF7NLN 9nQ6I+pDxVUaP5dZG0fQGSiM5YMbuWLeK8EXSi8iUI9NjNFRtoeDm6Y/W1ue1GAnBRVq lyNASCqsl6iQsholhARWqzqQ+ooA/XyRFiQme2izQcqhT4kawD2J2tRACaKOaqG5AgUC uS5DJjJR4rt1chrbuq6D9qLllsCuHWq0SoErn0Z151pq2CL76MaoomTjJK75HpGSw2vw cS3w== 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=66rTuFgUuVjzdvwr5vssBmJQ5naQ4mmWCVou0nSVcyk=; b=WozMv99M+ttuida9Alo/bqLZ1DohXcSxfMmcG6s6xesNytDUC/+9lP8GcE8S3/MAhs O+MgeYy1x3XjypPr2rVX5v4UglcMsis0/MqlpdkArq9Xhna6pikUQRTrmbReSEDg4xKz MbRrvxXM+FYm6kn440iWnh5cjb4vrAO1HPaWGaiwcC3JE8J3XLtDErzaox2gizkmDEKk jBFOsrHzHKs74NoWyMJ/5dD8+vmXujYzEwOfsJsiFZr66jivIbhPCNAqBs4G0Od1iIXs LgurtpAMP1qeu+17fqTJfHpqvOPGPBSwG2n6DypsofRige/BhL7Z0WJ58iZmwAUisLw6 rQ9Q== X-Gm-Message-State: APjAAAUM1Ptd7ygBA5fTt0JAvtLfmU2i9lkS7GFRt7FwkVFAdz8hBO4c QQGpHkb/4yCkSoU5Iwy6FnI= X-Google-Smtp-Source: APXvYqw2ukK3dKMvJT/3xQKKw/gOo9AaAFKu2BvlscxjpBz+CwcQSkBAvWRjSd4pUDjGe2EERdsLDA== X-Received: by 2002:a65:5144:: with SMTP id g4mr4270369pgq.202.1563579015384; Fri, 19 Jul 2019 16:30:15 -0700 (PDT) Received: from localhost.localdomain ([103.121.208.202]) by smtp.gmail.com with ESMTPSA id v13sm39150670pfn.109.2019.07.19.16.30.12 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 19 Jul 2019 16:30:14 -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 v2] fs: fs_parser: avoid NULL param->string to kstrtouint Date: Sat, 20 Jul 2019 07:29:49 +0800 Message-Id: <20190719232949.27978-1-nh26223.lmm@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- ChangeLog: v1 -> v2: - Fix typo in v1 - Remove braces {} from single statement blocks fs/fs_parser.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/fs_parser.c b/fs/fs_parser.c index 83b66c9e9a24..7498a44f18c0 100644 --- a/fs/fs_parser.c +++ b/fs/fs_parser.c @@ -206,6 +206,9 @@ 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: -- 2.17.1