From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:41284 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753027AbeBSPSZ (ORCPT ); Mon, 19 Feb 2018 10:18:25 -0500 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1JFFAXj075983 for ; Mon, 19 Feb 2018 10:18:25 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0b-001b2d01.pphosted.com with ESMTP id 2g80ebjc02-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 19 Feb 2018 10:18:24 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 19 Feb 2018 15:18:22 -0000 From: Mimi Zohar To: linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, Mimi Zohar , Miklos Szeredi , Seth Forshee , "Eric W . Biederman" , Dongsu Park , Alban Crequy , "Serge E. Hallyn" Subject: [PATCH v1 2/2] fuse: define the filesystem as untrusted Date: Mon, 19 Feb 2018 10:18:03 -0500 In-Reply-To: <1519053483-18396-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1519053483-18396-1-git-send-email-zohar@linux.vnet.ibm.com> Message-Id: <1519053483-18396-3-git-send-email-zohar@linux.vnet.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Files on FUSE can change at any point in time without IMA being able to detect it. The file data read for the file signature verification could be totally different from what is subsequently read, making the signature verification useless. FUSE can be mounted by unprivileged users either today with fusermount installed with setuid, or soon with the upcoming patches to allow FUSE mounts in a non-init user namespace. This patch sets the SB_I_IMA_UNTRUSTED_FS flag. Signed-off-by: Mimi Zohar Cc: Miklos Szeredi Cc: Seth Forshee Cc: Eric W. Biederman Cc: Dongsu Park Cc: Alban Crequy Cc: "Serge E. Hallyn" --- fs/fuse/inode.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 624f18bbfd2b..2cbf01fc85a2 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1080,6 +1080,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_time_gran = 1; sb->s_export_op = &fuse_export_operations; + sb->s_iflags |= SB_I_IMA_UNTRUSTED_FS; file = fget(d.fd); err = -EINVAL; -- 2.7.5