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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 CB978C83004 for ; Wed, 29 Apr 2020 16:17:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB4CD206F0 for ; Wed, 29 Apr 2020 16:17:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="duJ1CAR3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726775AbgD2QRz (ORCPT ); Wed, 29 Apr 2020 12:17:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726481AbgD2QRw (ORCPT ); Wed, 29 Apr 2020 12:17:52 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80854C03C1AE for ; Wed, 29 Apr 2020 09:17:52 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id g12so2669057wmh.3 for ; Wed, 29 Apr 2020 09:17:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=hC339AlYWIKjaIvmnsbzPnIvgC6f8npdAivdjP/WncE=; b=duJ1CAR3oC0XJTSkov4YIS7U0gdKnijRTK0zU7OF120jvwnIAqXrOiZukp76t7gqEg +sws3pAd0Fp715kcqIQUZ6ILybSDYsmpYBhd+d742FyzXAnETdeW6IOhAPErL4HwCrgM 462kB+7nxNLniPCRDs6WRnbW6aa9rbAFfqsEc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=hC339AlYWIKjaIvmnsbzPnIvgC6f8npdAivdjP/WncE=; b=YIhl6RdXV875ic1l0gWrkzZMWlMR0h9z5dAYorl924br/GH6zEwF/V91X2NG7qazzW KEqxv3mmE95PHkoas7k91MhdjX6sQW1CvZDBrPmGN1YaZDsYItbFpcFJDdH+i2GGT+Vx MELBpAITlxYOXnkVlrBfCmYxtOUZ4nqpO1Tz4jPAMd2Je7QmX1DNKVThl/MmqYiHgRMP omjst0kCztcbdgmrWf7oCRWYKQVQuDNIwEj+eZFwMFjC/IWUqnpNJIpR1KNYdQxmQwzs qqxE4JFRiXB0xuZr1hQ70MRUiYQK1LO1Ks1aq15CiT/oGTU7cov8CF11tK6O967RGYvQ m54w== X-Gm-Message-State: AGi0PuYoUh55bDd/uUfGnwS0rCVSosdXClrFqlwpkjAam/MN/hz2AXRv DFnNOeLG01IcRkHCorNIFMBlnQ== X-Google-Smtp-Source: APiQypKqSi/3QCJ/S4sT8BuxhRSzNwixocTEGZPtC0ytAcL+7Al93xW6am13M7Ws4l0ZyznfHMvcCQ== X-Received: by 2002:a1c:3dd6:: with SMTP id k205mr4139049wma.138.1588177071094; Wed, 29 Apr 2020 09:17:51 -0700 (PDT) Received: from google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id d143sm8275651wmd.16.2020.04.29.09.17.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Apr 2020 09:17:50 -0700 (PDT) From: KP Singh X-Google-Original-From: KP Singh Date: Wed, 29 Apr 2020 18:17:47 +0200 To: Mikko Ylinen Cc: KP Singh , open list , bpf , Linux Security Module list , Alexei Starovoitov , Daniel Borkmann , James Morris , Kees Cook , Paul Turner , Jann Horn , Florent Revest , Brendan Jackman , Greg Kroah-Hartman Subject: Re: [PATCH bpf-next v9 0/8] MAC and Audit policy using eBPF (KRSI) Message-ID: <20200429161747.GA113900@google.com> References: <20200329004356.27286-1-kpsingh@chromium.org> <0165887d-e9d0-c03e-18b9-72e74a0cbd59@linux.intel.com>

MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org So I was able to reproduce the issue and also fix it (will separately send a patch). diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 9cd4455528e5..1bdd027766d4 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -55,7 +55,7 @@ LSM_HOOK(void, LSM_RET_VOID, bprm_committing_creds, struct linux_binprm *bprm) LSM_HOOK(void, LSM_RET_VOID, bprm_committed_creds, struct linux_binprm *bprm) LSM_HOOK(int, 0, fs_context_dup, struct fs_context *fc, struct fs_context *src_sc) -LSM_HOOK(int, 0, fs_context_parse_param, struct fs_context *fc, +LSM_HOOK(int, -ENOPARAM, fs_context_parse_param, struct fs_context *fc, struct fs_parameter *param) LSM_HOOK(int, 0, sb_alloc_security, struct super_block *sb) LSM_HOOK(void, LSM_RET_VOID, sb_free_security, struct super_block *sb) So what was happening was that: bpf_lsm hook for fs_context_parse_param was returning 0 which led this bit of logic to believe the parameter was parsed by the LSM. int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param) { [...] ret = security_fs_context_parse_param(fc, param); if (ret != -ENOPARAM) /* Param belongs to the LSM or is disallowed by the * LSM; so * don't pass to the FS. */ return ret; if (fc->ops->parse_param) { ret = fc->ops->parse_param(fc, param); if (ret != -ENOPARAM) return ret; } [...] This resulted in the fs_context->dev_name being NULL and the following chain to throw an -EINVAL resulting in unsuccessful mount of the root file-system: - do_mount_root -> do_mount -> do_new_mount -> vfs_get_tree -> -> fc->ops->get_tree -> legacy->get_tree -> fc->fs_type->mount -> ext4_mount -> mount_bdev -> blkdev_get_by_path -> lookup_bdev - KP On 29-Apr 15:45, Mikko Ylinen wrote: > > > On 29/04/2020 15:34, KP Singh wrote: > > Thanks for reporting this! Can you share your Kconfig please? > > This is what I originally started with > https://raw.githubusercontent.com/clearlinux-pkgs/linux-mainline/master/config > > but I also tried your _LSM_ settings found in this > https://lore.kernel.org/bpf/20200402040357.GA217889@google.com/ > > -- Regards, Mikko