9fa5f6b4b9
implemented properly for a number of kernel subsystems. In general, they try to exercise the privilege first as the root user, then as a test user, in order to determine when privilege is being checked. Currently, these tests do not compare inside/outside jail, and probably should be enhanced to do that. Sponsored by: nCircle Network Security, Inc. Obtained from: TrustedBSD Project
114 lines
3.4 KiB
C
114 lines
3.4 KiB
C
/*-
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* Copyright (c) 2006 nCircle Network Security, Inc.
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* All rights reserved.
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*
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* This software was developed by Robert N. M. Watson for the TrustedBSD
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* Project under contract to nCircle Network Security, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY,
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* INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Confirm that a generation number isn't returned by stat() when not running
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* with privilege. In order to differentiate between a generation of 0 and
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* a generation not being returned, we have to create a temporary file known
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* to have a non-0 generation. We try up to 10 times, and then give up,
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* which is non-ideal, but better than not testing for a problem.
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*/
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#include <sys/stat.h>
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#include <err.h>
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#include <errno.h>
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#include <string.h>
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#include <unistd.h>
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#include "main.h"
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/*
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* Can't use setup_file() since the resulting file needs to have specific
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* properties.
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*/
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void
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priv_vfs_generation(void)
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{
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char fpath[1024] = "/tmp/priv.XXXXXXXXXX";
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struct stat sb;
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int fd, i;
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assert_root();
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/*
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* Create a file with a non-0 generation number. Try ten times,
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* which gives a high chance of succeeds, fail otherwise. Not ideal,
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* since we can't distinguish the file having a generation of 0 from
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* not being able to query it for access control reasons. The perils
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* of an API that changes behavior based on lack of privilege rather
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* than failing...
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*/
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for (i = 0; i < 10; i++) {
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fd = mkstemp(fpath);
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if (fd < 0)
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err(-1, "mkstemp");
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if (fstat(fd, &sb) < 0) {
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warn("fstat(%s)", fpath);
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close(fd);
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goto out;
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}
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if (sb.st_gen != 0)
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break;
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close(fd);
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(void)unlink(fpath);
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strcpy(fpath, "/tmp/generation.XXXXXXXXXX");
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fd = -1;
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}
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if (fd == -1)
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errx(-1,
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"could not create file with non-0 generation as root");
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close(fd);
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/*
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* We've already tested that fstat() works, but try stat() to be
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* consistent between privileged and unprivileged tests.
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*/
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if (stat(fpath, &sb) < 0) {
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warn("stat(%s) as root", fpath);
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goto out;
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}
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set_euid(UID_OTHER);
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if (stat(fpath, &sb) < 0) {
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warn("stat(%s) as !root", fpath);
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goto out;
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}
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if (sb.st_gen != 0)
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warn("stat(%s) returned generation as !root", fpath);
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out:
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(void)seteuid(UID_ROOT);
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(void)unlink(fpath);
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}
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