[BACK]Return to fdpass.h CVS log [TXT][DIR] Up to [local] / src / usr.bin / sndiod
File: [local] / src / usr.bin / sndiod / fdpass.h (download)

Revision 1.1, Sun Dec 20 11:38:33 2015 UTC (8 years, 5 months ago) by ratchov
Branch: MAIN
CVS Tags: OPENBSD_6_6_BASE, OPENBSD_6_6, OPENBSD_6_5_BASE, OPENBSD_6_5, OPENBSD_6_4_BASE, OPENBSD_6_4, OPENBSD_6_3_BASE, OPENBSD_6_3, OPENBSD_6_2_BASE, OPENBSD_6_2, OPENBSD_6_1_BASE, OPENBSD_6_1, OPENBSD_6_0_BASE, OPENBSD_6_0, OPENBSD_5_9_BASE, OPENBSD_5_9 

In case of a bug in sndiod, an attacker (a local user) could run
arbitrary code as user _sndio, i.e. get a second uid.

Mitigate the risk by implementing initial privilege separation as
follows. Break sndiod in two processes: a chroot()ed "worker" process
processing input, and a non-chroot()ed "helper" process opening
devices and passing descriptors to the worker.

With help from benno, claudio, semarie and gilles.

ok benno, semarie and tb

/*	$OpenBSD: fdpass.h,v 1.1 2015/12/20 11:38:33 ratchov Exp $	*/
/*
 * Copyright (c) 2015 Alexandre Ratchov <alex@caoua.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#ifndef FDPASS_H
#define FDPASS_H

struct fileops;

struct fdpass *fdpass_new(int sock, struct fileops *ops);
void fdpass_close(struct fdpass *f);

extern struct fileops worker_fileops, helper_fileops;
extern struct fdpass *fdpass_peer;

struct sio_hdl *fdpass_sio_open(int, unsigned int);
struct mio_hdl *fdpass_mio_open(int, unsigned int);

#endif /* !defined(FDPASS_H) */