1332 lines
29 KiB
C
1332 lines
29 KiB
C
/*
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* Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, 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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_prot.c 8.6 (Berkeley) 1/21/94
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* $FreeBSD$
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*/
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/*
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* System calls related to processes and protection
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*/
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#include "opt_compat.h"
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#include <sys/param.h>
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#include <sys/acct.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/proc.h>
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#include <sys/malloc.h>
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#include <sys/pioctl.h>
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#include <sys/resourcevar.h>
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#include <sys/sysctl.h>
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static MALLOC_DEFINE(M_CRED, "cred", "credentials");
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#ifndef _SYS_SYSPROTO_H_
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struct getpid_args {
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int dummy;
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};
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#endif
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/*
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* getpid - MP SAFE
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*/
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/* ARGSUSED */
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int
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getpid(p, uap)
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struct proc *p;
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struct getpid_args *uap;
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{
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p->p_retval[0] = p->p_pid;
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#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
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PROCTREE_LOCK(PT_SHARED);
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p->p_retval[1] = p->p_pptr->p_pid;
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PROCTREE_LOCK(PT_RELEASE);
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#endif
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return (0);
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}
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/*
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* getppid - MP SAFE
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct getppid_args {
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int dummy;
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};
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#endif
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/* ARGSUSED */
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int
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getppid(p, uap)
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struct proc *p;
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struct getppid_args *uap;
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{
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PROCTREE_LOCK(PT_SHARED);
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p->p_retval[0] = p->p_pptr->p_pid;
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PROCTREE_LOCK(PT_RELEASE);
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return (0);
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}
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/*
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* Get process group ID; note that POSIX getpgrp takes no parameter
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*
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* MP SAFE
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct getpgrp_args {
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int dummy;
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};
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#endif
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int
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getpgrp(p, uap)
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struct proc *p;
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struct getpgrp_args *uap;
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{
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p->p_retval[0] = p->p_pgrp->pg_id;
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return (0);
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}
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/* Get an arbitary pid's process group id */
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#ifndef _SYS_SYSPROTO_H_
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struct getpgid_args {
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pid_t pid;
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};
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#endif
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int
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getpgid(p, uap)
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struct proc *p;
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struct getpgid_args *uap;
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{
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struct proc *pt;
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pt = p;
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if (uap->pid == 0)
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goto found;
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if ((pt = pfind(uap->pid)) == 0)
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return ESRCH;
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found:
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p->p_retval[0] = pt->p_pgrp->pg_id;
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return 0;
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}
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/*
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* Get an arbitary pid's session id.
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct getsid_args {
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pid_t pid;
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};
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#endif
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int
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getsid(p, uap)
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struct proc *p;
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struct getsid_args *uap;
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{
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struct proc *pt;
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pt = p;
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if (uap->pid == 0)
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goto found;
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if ((pt = pfind(uap->pid)) == 0)
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return ESRCH;
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found:
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p->p_retval[0] = pt->p_session->s_sid;
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return 0;
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}
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/*
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* getuid() - MP SAFE
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct getuid_args {
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int dummy;
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};
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#endif
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/* ARGSUSED */
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int
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getuid(p, uap)
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struct proc *p;
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struct getuid_args *uap;
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{
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p->p_retval[0] = p->p_cred->p_ruid;
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#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
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p->p_retval[1] = p->p_ucred->cr_uid;
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#endif
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return (0);
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}
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/*
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* geteuid() - MP SAFE
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct geteuid_args {
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int dummy;
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};
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#endif
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/* ARGSUSED */
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int
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geteuid(p, uap)
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struct proc *p;
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struct geteuid_args *uap;
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{
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p->p_retval[0] = p->p_ucred->cr_uid;
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return (0);
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}
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/*
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* getgid() - MP SAFE
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct getgid_args {
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int dummy;
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};
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#endif
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/* ARGSUSED */
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int
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getgid(p, uap)
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struct proc *p;
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struct getgid_args *uap;
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{
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p->p_retval[0] = p->p_cred->p_rgid;
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#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
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p->p_retval[1] = p->p_ucred->cr_groups[0];
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#endif
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return (0);
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}
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/*
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* Get effective group ID. The "egid" is groups[0], and could be obtained
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* via getgroups. This syscall exists because it is somewhat painful to do
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* correctly in a library function.
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct getegid_args {
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int dummy;
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};
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#endif
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/* ARGSUSED */
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int
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getegid(p, uap)
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struct proc *p;
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struct getegid_args *uap;
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{
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p->p_retval[0] = p->p_ucred->cr_groups[0];
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return (0);
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}
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#ifndef _SYS_SYSPROTO_H_
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struct getgroups_args {
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u_int gidsetsize;
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gid_t *gidset;
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};
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#endif
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int
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getgroups(p, uap)
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struct proc *p;
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register struct getgroups_args *uap;
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{
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register struct pcred *pc = p->p_cred;
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register u_int ngrp;
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int error;
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if ((ngrp = uap->gidsetsize) == 0) {
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p->p_retval[0] = pc->pc_ucred->cr_ngroups;
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return (0);
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}
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if (ngrp < pc->pc_ucred->cr_ngroups)
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return (EINVAL);
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ngrp = pc->pc_ucred->cr_ngroups;
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if ((error = copyout((caddr_t)pc->pc_ucred->cr_groups,
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(caddr_t)uap->gidset, ngrp * sizeof(gid_t))))
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return (error);
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p->p_retval[0] = ngrp;
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return (0);
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}
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#ifndef _SYS_SYSPROTO_H_
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struct setsid_args {
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int dummy;
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};
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#endif
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/* ARGSUSED */
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int
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setsid(p, uap)
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register struct proc *p;
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struct setsid_args *uap;
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{
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if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) {
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return (EPERM);
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} else {
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(void)enterpgrp(p, p->p_pid, 1);
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p->p_retval[0] = p->p_pid;
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return (0);
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}
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}
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/*
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* set process group (setpgid/old setpgrp)
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*
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* caller does setpgid(targpid, targpgid)
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*
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* pid must be caller or child of caller (ESRCH)
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* if a child
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* pid must be in same session (EPERM)
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* pid can't have done an exec (EACCES)
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* if pgid != pid
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* there must exist some pid in same session having pgid (EPERM)
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* pid must not be session leader (EPERM)
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct setpgid_args {
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int pid; /* target process id */
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int pgid; /* target pgrp id */
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};
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#endif
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/* ARGSUSED */
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int
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setpgid(curp, uap)
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struct proc *curp;
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register struct setpgid_args *uap;
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{
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register struct proc *targp; /* target process */
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register struct pgrp *pgrp; /* target pgrp */
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if (uap->pgid < 0)
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return (EINVAL);
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if (uap->pid != 0 && uap->pid != curp->p_pid) {
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if ((targp = pfind(uap->pid)) == 0 || !inferior(targp))
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return (ESRCH);
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if (targp->p_pgrp == NULL || targp->p_session != curp->p_session)
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return (EPERM);
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if (targp->p_flag & P_EXEC)
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return (EACCES);
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} else
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targp = curp;
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if (SESS_LEADER(targp))
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return (EPERM);
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if (uap->pgid == 0)
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uap->pgid = targp->p_pid;
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else if (uap->pgid != targp->p_pid)
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if ((pgrp = pgfind(uap->pgid)) == 0 ||
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pgrp->pg_session != curp->p_session)
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return (EPERM);
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return (enterpgrp(targp, uap->pgid, 0));
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}
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/*
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* Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD
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* compatable. It says that setting the uid/gid to euid/egid is a special
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* case of "appropriate privilege". Once the rules are expanded out, this
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* basically means that setuid(nnn) sets all three id's, in all permitted
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* cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid())
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* does not set the saved id - this is dangerous for traditional BSD
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* programs. For this reason, we *really* do not want to set
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* _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2.
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*/
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#define POSIX_APPENDIX_B_4_2_2
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#ifndef _SYS_SYSPROTO_H_
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struct setuid_args {
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uid_t uid;
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};
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#endif
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/* ARGSUSED */
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int
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setuid(p, uap)
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struct proc *p;
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struct setuid_args *uap;
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{
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register struct pcred *pc = p->p_cred;
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register uid_t uid;
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int error;
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/*
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* See if we have "permission" by POSIX 1003.1 rules.
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*
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* Note that setuid(geteuid()) is a special case of
|
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* "appropriate privileges" in appendix B.4.2.2. We need
|
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* to use this clause to be compatable with traditional BSD
|
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* semantics. Basically, it means that "setuid(xx)" sets all
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* three id's (assuming you have privs).
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*
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* Notes on the logic. We do things in three steps.
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* 1: We determine if the euid is going to change, and do EPERM
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* right away. We unconditionally change the euid later if this
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* test is satisfied, simplifying that part of the logic.
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* 2: We determine if the real and/or saved uid's are going to
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* change. Determined by compile options.
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* 3: Change euid last. (after tests in #2 for "appropriate privs")
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*/
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uid = uap->uid;
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if (uid != pc->p_ruid && /* allow setuid(getuid()) */
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#ifdef _POSIX_SAVED_IDS
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uid != pc->p_svuid && /* allow setuid(saved gid) */
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#endif
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#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
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uid != pc->pc_ucred->cr_uid && /* allow setuid(geteuid()) */
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#endif
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(error = suser_xxx(0, p, PRISON_ROOT)))
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return (error);
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|
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#ifdef _POSIX_SAVED_IDS
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/*
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* Do we have "appropriate privileges" (are we root or uid == euid)
|
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* If so, we are changing the real uid and/or saved uid.
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|
*/
|
|
if (
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#ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */
|
|
uid == pc->pc_ucred->cr_uid ||
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#endif
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suser_xxx(0, p, PRISON_ROOT) == 0) /* we are using privs */
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|
#endif
|
|
{
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|
/*
|
|
* Set the real uid and transfer proc count to new user.
|
|
*/
|
|
if (uid != pc->p_ruid) {
|
|
change_ruid(p, uid);
|
|
setsugid(p);
|
|
}
|
|
/*
|
|
* Set saved uid
|
|
*
|
|
* XXX always set saved uid even if not _POSIX_SAVED_IDS, as
|
|
* the security of seteuid() depends on it. B.4.2.2 says it
|
|
* is important that we should do this.
|
|
*/
|
|
if (pc->p_svuid != uid) {
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|
pc->p_svuid = uid;
|
|
setsugid(p);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* In all permitted cases, we are changing the euid.
|
|
* Copy credentials so other references do not see our changes.
|
|
*/
|
|
if (pc->pc_ucred->cr_uid != uid) {
|
|
change_euid(p, uid);
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct seteuid_args {
|
|
uid_t euid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
seteuid(p, uap)
|
|
struct proc *p;
|
|
struct seteuid_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register uid_t euid;
|
|
int error;
|
|
|
|
euid = uap->euid;
|
|
if (euid != pc->p_ruid && /* allow seteuid(getuid()) */
|
|
euid != pc->p_svuid && /* allow seteuid(saved uid) */
|
|
(error = suser_xxx(0, p, PRISON_ROOT)))
|
|
return (error);
|
|
/*
|
|
* Everything's okay, do it. Copy credentials so other references do
|
|
* not see our changes.
|
|
*/
|
|
if (pc->pc_ucred->cr_uid != euid) {
|
|
change_euid(p, euid);
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setgid_args {
|
|
gid_t gid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setgid(p, uap)
|
|
struct proc *p;
|
|
struct setgid_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register gid_t gid;
|
|
int error;
|
|
|
|
/*
|
|
* See if we have "permission" by POSIX 1003.1 rules.
|
|
*
|
|
* Note that setgid(getegid()) is a special case of
|
|
* "appropriate privileges" in appendix B.4.2.2. We need
|
|
* to use this clause to be compatable with traditional BSD
|
|
* semantics. Basically, it means that "setgid(xx)" sets all
|
|
* three id's (assuming you have privs).
|
|
*
|
|
* For notes on the logic here, see setuid() above.
|
|
*/
|
|
gid = uap->gid;
|
|
if (gid != pc->p_rgid && /* allow setgid(getgid()) */
|
|
#ifdef _POSIX_SAVED_IDS
|
|
gid != pc->p_svgid && /* allow setgid(saved gid) */
|
|
#endif
|
|
#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
|
|
gid != pc->pc_ucred->cr_groups[0] && /* allow setgid(getegid()) */
|
|
#endif
|
|
(error = suser_xxx(0, p, PRISON_ROOT)))
|
|
return (error);
|
|
|
|
#ifdef _POSIX_SAVED_IDS
|
|
/*
|
|
* Do we have "appropriate privileges" (are we root or gid == egid)
|
|
* If so, we are changing the real uid and saved gid.
|
|
*/
|
|
if (
|
|
#ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */
|
|
gid == pc->pc_ucred->cr_groups[0] ||
|
|
#endif
|
|
suser_xxx(0, p, PRISON_ROOT) == 0) /* we are using privs */
|
|
#endif
|
|
{
|
|
/*
|
|
* Set real gid
|
|
*/
|
|
if (pc->p_rgid != gid) {
|
|
pc->p_rgid = gid;
|
|
setsugid(p);
|
|
}
|
|
/*
|
|
* Set saved gid
|
|
*
|
|
* XXX always set saved gid even if not _POSIX_SAVED_IDS, as
|
|
* the security of setegid() depends on it. B.4.2.2 says it
|
|
* is important that we should do this.
|
|
*/
|
|
if (pc->p_svgid != gid) {
|
|
pc->p_svgid = gid;
|
|
setsugid(p);
|
|
}
|
|
}
|
|
/*
|
|
* In all cases permitted cases, we are changing the egid.
|
|
* Copy credentials so other references do not see our changes.
|
|
*/
|
|
if (pc->pc_ucred->cr_groups[0] != gid) {
|
|
pc->pc_ucred = crcopy(pc->pc_ucred);
|
|
pc->pc_ucred->cr_groups[0] = gid;
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setegid_args {
|
|
gid_t egid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setegid(p, uap)
|
|
struct proc *p;
|
|
struct setegid_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register gid_t egid;
|
|
int error;
|
|
|
|
egid = uap->egid;
|
|
if (egid != pc->p_rgid && /* allow setegid(getgid()) */
|
|
egid != pc->p_svgid && /* allow setegid(saved gid) */
|
|
(error = suser_xxx(0, p, PRISON_ROOT)))
|
|
return (error);
|
|
if (pc->pc_ucred->cr_groups[0] != egid) {
|
|
pc->pc_ucred = crcopy(pc->pc_ucred);
|
|
pc->pc_ucred->cr_groups[0] = egid;
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setgroups_args {
|
|
u_int gidsetsize;
|
|
gid_t *gidset;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setgroups(p, uap)
|
|
struct proc *p;
|
|
struct setgroups_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register u_int ngrp;
|
|
int error;
|
|
|
|
if ((error = suser_xxx(0, p, PRISON_ROOT)))
|
|
return (error);
|
|
ngrp = uap->gidsetsize;
|
|
if (ngrp > NGROUPS)
|
|
return (EINVAL);
|
|
/*
|
|
* XXX A little bit lazy here. We could test if anything has
|
|
* changed before crcopy() and setting P_SUGID.
|
|
*/
|
|
pc->pc_ucred = crcopy(pc->pc_ucred);
|
|
if (ngrp < 1) {
|
|
/*
|
|
* setgroups(0, NULL) is a legitimate way of clearing the
|
|
* groups vector on non-BSD systems (which generally do not
|
|
* have the egid in the groups[0]). We risk security holes
|
|
* when running non-BSD software if we do not do the same.
|
|
*/
|
|
pc->pc_ucred->cr_ngroups = 1;
|
|
} else {
|
|
if ((error = copyin((caddr_t)uap->gidset,
|
|
(caddr_t)pc->pc_ucred->cr_groups, ngrp * sizeof(gid_t))))
|
|
return (error);
|
|
pc->pc_ucred->cr_ngroups = ngrp;
|
|
}
|
|
setsugid(p);
|
|
return (0);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setreuid_args {
|
|
uid_t ruid;
|
|
uid_t euid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setreuid(p, uap)
|
|
register struct proc *p;
|
|
struct setreuid_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register uid_t ruid, euid;
|
|
int error;
|
|
|
|
ruid = uap->ruid;
|
|
euid = uap->euid;
|
|
if (((ruid != (uid_t)-1 && ruid != pc->p_ruid && ruid != pc->p_svuid) ||
|
|
(euid != (uid_t)-1 && euid != pc->pc_ucred->cr_uid &&
|
|
euid != pc->p_ruid && euid != pc->p_svuid)) &&
|
|
(error = suser_xxx(0, p, PRISON_ROOT)) != 0)
|
|
return (error);
|
|
|
|
if (euid != (uid_t)-1 && pc->pc_ucred->cr_uid != euid) {
|
|
change_euid(p, euid);
|
|
setsugid(p);
|
|
}
|
|
if (ruid != (uid_t)-1 && pc->p_ruid != ruid) {
|
|
change_ruid(p, ruid);
|
|
setsugid(p);
|
|
}
|
|
if ((ruid != (uid_t)-1 || pc->pc_ucred->cr_uid != pc->p_ruid) &&
|
|
pc->p_svuid != pc->pc_ucred->cr_uid) {
|
|
pc->p_svuid = pc->pc_ucred->cr_uid;
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setregid_args {
|
|
gid_t rgid;
|
|
gid_t egid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setregid(p, uap)
|
|
register struct proc *p;
|
|
struct setregid_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register gid_t rgid, egid;
|
|
int error;
|
|
|
|
rgid = uap->rgid;
|
|
egid = uap->egid;
|
|
if (((rgid != (gid_t)-1 && rgid != pc->p_rgid && rgid != pc->p_svgid) ||
|
|
(egid != (gid_t)-1 && egid != pc->pc_ucred->cr_groups[0] &&
|
|
egid != pc->p_rgid && egid != pc->p_svgid)) &&
|
|
(error = suser_xxx(0, p, PRISON_ROOT)) != 0)
|
|
return (error);
|
|
|
|
if (egid != (gid_t)-1 && pc->pc_ucred->cr_groups[0] != egid) {
|
|
pc->pc_ucred = crcopy(pc->pc_ucred);
|
|
pc->pc_ucred->cr_groups[0] = egid;
|
|
setsugid(p);
|
|
}
|
|
if (rgid != (gid_t)-1 && pc->p_rgid != rgid) {
|
|
pc->p_rgid = rgid;
|
|
setsugid(p);
|
|
}
|
|
if ((rgid != (gid_t)-1 || pc->pc_ucred->cr_groups[0] != pc->p_rgid) &&
|
|
pc->p_svgid != pc->pc_ucred->cr_groups[0]) {
|
|
pc->p_svgid = pc->pc_ucred->cr_groups[0];
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* setresuid(ruid, euid, suid) is like setreuid except control over the
|
|
* saved uid is explicit.
|
|
*/
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setresuid_args {
|
|
uid_t ruid;
|
|
uid_t euid;
|
|
uid_t suid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setresuid(p, uap)
|
|
register struct proc *p;
|
|
struct setresuid_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register uid_t ruid, euid, suid;
|
|
int error;
|
|
|
|
ruid = uap->ruid;
|
|
euid = uap->euid;
|
|
suid = uap->suid;
|
|
if (((ruid != (uid_t)-1 && ruid != pc->p_ruid && ruid != pc->p_svuid &&
|
|
ruid != pc->pc_ucred->cr_uid) ||
|
|
(euid != (uid_t)-1 && euid != pc->p_ruid && euid != pc->p_svuid &&
|
|
euid != pc->pc_ucred->cr_uid) ||
|
|
(suid != (uid_t)-1 && suid != pc->p_ruid && suid != pc->p_svuid &&
|
|
suid != pc->pc_ucred->cr_uid)) &&
|
|
(error = suser_xxx(0, p, PRISON_ROOT)) != 0)
|
|
return (error);
|
|
if (euid != (uid_t)-1 && pc->pc_ucred->cr_uid != euid) {
|
|
change_euid(p, euid);
|
|
setsugid(p);
|
|
}
|
|
if (ruid != (uid_t)-1 && pc->p_ruid != ruid) {
|
|
change_ruid(p, ruid);
|
|
setsugid(p);
|
|
}
|
|
if (suid != (uid_t)-1 && pc->p_svuid != suid) {
|
|
pc->p_svuid = suid;
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* setresgid(rgid, egid, sgid) is like setregid except control over the
|
|
* saved gid is explicit.
|
|
*/
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setresgid_args {
|
|
gid_t rgid;
|
|
gid_t egid;
|
|
gid_t sgid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setresgid(p, uap)
|
|
register struct proc *p;
|
|
struct setresgid_args *uap;
|
|
{
|
|
register struct pcred *pc = p->p_cred;
|
|
register gid_t rgid, egid, sgid;
|
|
int error;
|
|
|
|
rgid = uap->rgid;
|
|
egid = uap->egid;
|
|
sgid = uap->sgid;
|
|
if (((rgid != (gid_t)-1 && rgid != pc->p_rgid && rgid != pc->p_svgid &&
|
|
rgid != pc->pc_ucred->cr_groups[0]) ||
|
|
(egid != (gid_t)-1 && egid != pc->p_rgid && egid != pc->p_svgid &&
|
|
egid != pc->pc_ucred->cr_groups[0]) ||
|
|
(sgid != (gid_t)-1 && sgid != pc->p_rgid && sgid != pc->p_svgid &&
|
|
sgid != pc->pc_ucred->cr_groups[0])) &&
|
|
(error = suser_xxx(0, p, PRISON_ROOT)) != 0)
|
|
return (error);
|
|
|
|
if (egid != (gid_t)-1 && pc->pc_ucred->cr_groups[0] != egid) {
|
|
pc->pc_ucred = crcopy(pc->pc_ucred);
|
|
pc->pc_ucred->cr_groups[0] = egid;
|
|
setsugid(p);
|
|
}
|
|
if (rgid != (gid_t)-1 && pc->p_rgid != rgid) {
|
|
pc->p_rgid = rgid;
|
|
setsugid(p);
|
|
}
|
|
if (sgid != (gid_t)-1 && pc->p_svgid != sgid) {
|
|
pc->p_svgid = sgid;
|
|
setsugid(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct getresuid_args {
|
|
uid_t *ruid;
|
|
uid_t *euid;
|
|
uid_t *suid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
getresuid(p, uap)
|
|
register struct proc *p;
|
|
struct getresuid_args *uap;
|
|
{
|
|
struct pcred *pc = p->p_cred;
|
|
int error1 = 0, error2 = 0, error3 = 0;
|
|
|
|
if (uap->ruid)
|
|
error1 = copyout((caddr_t)&pc->p_ruid,
|
|
(caddr_t)uap->ruid, sizeof(pc->p_ruid));
|
|
if (uap->euid)
|
|
error2 = copyout((caddr_t)&pc->pc_ucred->cr_uid,
|
|
(caddr_t)uap->euid, sizeof(pc->pc_ucred->cr_uid));
|
|
if (uap->suid)
|
|
error3 = copyout((caddr_t)&pc->p_svuid,
|
|
(caddr_t)uap->suid, sizeof(pc->p_svuid));
|
|
return error1 ? error1 : (error2 ? error2 : error3);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct getresgid_args {
|
|
gid_t *rgid;
|
|
gid_t *egid;
|
|
gid_t *sgid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
getresgid(p, uap)
|
|
register struct proc *p;
|
|
struct getresgid_args *uap;
|
|
{
|
|
struct pcred *pc = p->p_cred;
|
|
int error1 = 0, error2 = 0, error3 = 0;
|
|
|
|
if (uap->rgid)
|
|
error1 = copyout((caddr_t)&pc->p_rgid,
|
|
(caddr_t)uap->rgid, sizeof(pc->p_rgid));
|
|
if (uap->egid)
|
|
error2 = copyout((caddr_t)&pc->pc_ucred->cr_groups[0],
|
|
(caddr_t)uap->egid, sizeof(pc->pc_ucred->cr_groups[0]));
|
|
if (uap->sgid)
|
|
error3 = copyout((caddr_t)&pc->p_svgid,
|
|
(caddr_t)uap->sgid, sizeof(pc->p_svgid));
|
|
return error1 ? error1 : (error2 ? error2 : error3);
|
|
}
|
|
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct issetugid_args {
|
|
int dummy;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
issetugid(p, uap)
|
|
register struct proc *p;
|
|
struct issetugid_args *uap;
|
|
{
|
|
/*
|
|
* Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
|
|
* we use P_SUGID because we consider changing the owners as
|
|
* "tainting" as well.
|
|
* This is significant for procs that start as root and "become"
|
|
* a user without an exec - programs cannot know *everything*
|
|
* that libc *might* have put in their data segment.
|
|
*/
|
|
p->p_retval[0] = (p->p_flag & P_SUGID) ? 1 : 0;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Check if gid is a member of the group set.
|
|
*/
|
|
int
|
|
groupmember(gid, cred)
|
|
gid_t gid;
|
|
register struct ucred *cred;
|
|
{
|
|
register gid_t *gp;
|
|
gid_t *egp;
|
|
|
|
egp = &(cred->cr_groups[cred->cr_ngroups]);
|
|
for (gp = cred->cr_groups; gp < egp; gp++)
|
|
if (*gp == gid)
|
|
return (1);
|
|
return (0);
|
|
}
|
|
|
|
static int suser_permitted = 1;
|
|
|
|
SYSCTL_INT(_kern, OID_AUTO, suser_permitted, CTLFLAG_RW, &suser_permitted, 0,
|
|
"processes with uid 0 have privilege");
|
|
|
|
/*
|
|
* Test whether the specified credentials imply "super-user"
|
|
* privilege; if so, and we have accounting info, set the flag
|
|
* indicating use of super-powers.
|
|
* Returns 0 or error.
|
|
*/
|
|
int
|
|
suser(p)
|
|
const struct proc *p;
|
|
{
|
|
return suser_xxx(0, p, 0);
|
|
}
|
|
|
|
int
|
|
suser_xxx(cred, proc, flag)
|
|
const struct ucred *cred;
|
|
const struct proc *proc;
|
|
int flag;
|
|
{
|
|
if (!suser_permitted)
|
|
return (EPERM);
|
|
if (!cred && !proc) {
|
|
printf("suser_xxx(): THINK!\n");
|
|
return (EPERM);
|
|
}
|
|
if (!cred)
|
|
cred = proc->p_ucred;
|
|
if (cred->cr_uid != 0)
|
|
return (EPERM);
|
|
if (proc && proc->p_prison && !(flag & PRISON_ROOT))
|
|
return (EPERM);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
p_cansee(const struct proc *p1, const struct proc *p2, int *privused)
|
|
{
|
|
|
|
if (privused != NULL)
|
|
*privused = 0;
|
|
|
|
if (!PRISON_CHECK(p1, p2))
|
|
return (ESRCH);
|
|
|
|
if (!ps_showallprocs && p1->p_ucred->cr_uid != p2->p_ucred->cr_uid) {
|
|
if (suser_xxx(NULL, p1, PRISON_ROOT) == 0) {
|
|
if (privused != NULL)
|
|
*privused = 1;
|
|
return (0);
|
|
}
|
|
return (ESRCH);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
p_cankill(const struct proc *p1, const struct proc *p2, int *privused)
|
|
{
|
|
|
|
if (privused != NULL)
|
|
*privused = 0;
|
|
|
|
if (p1 == p2)
|
|
return (0);
|
|
|
|
if (!PRISON_CHECK(p1, p2))
|
|
return (ESRCH);
|
|
|
|
if (p1->p_cred->p_ruid == p2->p_cred->p_ruid)
|
|
return (0);
|
|
if (p1->p_ucred->cr_uid == p2->p_cred->p_ruid)
|
|
return (0);
|
|
/*
|
|
* XXX should a process be able to affect another process
|
|
* acting as the same uid (i.e., a userland nfsd or the like?)
|
|
*/
|
|
if (p1->p_cred->p_ruid == p2->p_ucred->cr_uid)
|
|
return (0);
|
|
if (p1->p_ucred->cr_uid == p2->p_ucred->cr_uid)
|
|
return (0);
|
|
|
|
if (!suser_xxx(0, p1, PRISON_ROOT)) {
|
|
if (privused != NULL)
|
|
*privused = 1;
|
|
return (0);
|
|
}
|
|
|
|
#ifdef CAPABILITIES
|
|
if (!cap_check_xxx(0, p1, CAP_KILL, PRISON_ROOT)) {
|
|
if (privused != NULL)
|
|
*privused = 1;
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
return (EPERM);
|
|
}
|
|
|
|
static int
|
|
p_cansched(const struct proc *p1, const struct proc *p2, int *privused)
|
|
{
|
|
|
|
if (privused != NULL)
|
|
*privused = 0;
|
|
|
|
if (p1 == p2)
|
|
return (0);
|
|
|
|
if (!PRISON_CHECK(p1, p2))
|
|
return (ESRCH);
|
|
|
|
if (p1->p_cred->p_ruid == p2->p_cred->p_ruid)
|
|
return (0);
|
|
if (p1->p_ucred->cr_uid == p2->p_cred->p_ruid)
|
|
return (0);
|
|
/*
|
|
* XXX should a process be able to affect another process
|
|
* acting as the same uid (i.e., a userland nfsd or the like?)
|
|
*/
|
|
if (p1->p_cred->p_ruid == p2->p_ucred->cr_uid)
|
|
return (0);
|
|
if (p1->p_ucred->cr_uid == p2->p_ucred->cr_uid)
|
|
return (0);
|
|
|
|
if (!suser_xxx(0, p1, PRISON_ROOT)) {
|
|
if (privused != NULL)
|
|
*privused = 1;
|
|
return (0);
|
|
}
|
|
|
|
#ifdef CAPABILITIES
|
|
if (!cap_check_xxx(0, p1, CAP_SYS_NICE, PRISON_ROOT)) {
|
|
if (privused != NULL)
|
|
*privused = 1;
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
return (EPERM);
|
|
}
|
|
|
|
static int
|
|
p_candebug(const struct proc *p1, const struct proc *p2, int *privused)
|
|
{
|
|
int error;
|
|
|
|
if (privused != NULL)
|
|
*privused = 0;
|
|
|
|
/* XXX it is authorized, but semantics don't permit it */
|
|
if (p1 == p2)
|
|
return (0);
|
|
|
|
if (!PRISON_CHECK(p1, p2))
|
|
return (ESRCH);
|
|
|
|
/* not owned by you, has done setuid (unless you're root) */
|
|
/* add a CAP_SYS_PTRACE here? */
|
|
if (p1->p_cred->pc_ucred->cr_uid != p2->p_cred->p_ruid ||
|
|
p1->p_cred->p_ruid != p2->p_cred->p_ruid ||
|
|
p1->p_cred->p_svuid != p2->p_cred->p_ruid ||
|
|
p2->p_flag & P_SUGID) {
|
|
if ((error = suser_xxx(0, p1, PRISON_ROOT)))
|
|
return (error);
|
|
if (privused != NULL)
|
|
*privused = 1;
|
|
}
|
|
|
|
/* can't trace init when securelevel > 0 */
|
|
if (securelevel > 0 && p2->p_pid == 1)
|
|
return (EPERM);
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
p_can(const struct proc *p1, const struct proc *p2, int operation,
|
|
int *privused)
|
|
{
|
|
|
|
switch(operation) {
|
|
case P_CAN_SEE:
|
|
return (p_cansee(p1, p2, privused));
|
|
|
|
case P_CAN_KILL:
|
|
return (p_cankill(p1, p2, privused));
|
|
|
|
case P_CAN_SCHED:
|
|
return (p_cansched(p1, p2, privused));
|
|
|
|
case P_CAN_DEBUG:
|
|
return (p_candebug(p1, p2, privused));
|
|
|
|
default:
|
|
panic("p_can: invalid operation");
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Allocate a zeroed cred structure.
|
|
*/
|
|
struct ucred *
|
|
crget()
|
|
{
|
|
register struct ucred *cr;
|
|
|
|
MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK|M_ZERO);
|
|
cr->cr_ref = 1;
|
|
mtx_init(&cr->cr_mtx, "ucred", MTX_DEF);
|
|
return (cr);
|
|
}
|
|
|
|
/*
|
|
* Claim another referernce to a ucred structure
|
|
*/
|
|
void
|
|
crhold(cr)
|
|
struct ucred *cr;
|
|
{
|
|
|
|
mtx_enter(&cr->cr_mtx, MTX_DEF);
|
|
cr->cr_ref++;
|
|
mtx_exit(&(cr)->cr_mtx, MTX_DEF);
|
|
}
|
|
|
|
|
|
/*
|
|
* Free a cred structure.
|
|
* Throws away space when ref count gets to 0.
|
|
*/
|
|
void
|
|
crfree(cr)
|
|
struct ucred *cr;
|
|
{
|
|
|
|
mtx_enter(&cr->cr_mtx, MTX_DEF);
|
|
if (--cr->cr_ref == 0) {
|
|
mtx_destroy(&cr->cr_mtx);
|
|
/*
|
|
* Some callers of crget(), such as nfs_statfs(),
|
|
* allocate a temporary credential, but don't
|
|
* allocate a uidinfo structure.
|
|
*/
|
|
if (cr->cr_uidinfo != NULL)
|
|
uifree(cr->cr_uidinfo);
|
|
FREE((caddr_t)cr, M_CRED);
|
|
} else {
|
|
mtx_exit(&cr->cr_mtx, MTX_DEF);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy cred structure to a new one and free the old one.
|
|
*/
|
|
struct ucred *
|
|
crcopy(cr)
|
|
struct ucred *cr;
|
|
{
|
|
struct ucred *newcr;
|
|
|
|
mtx_enter(&cr->cr_mtx, MTX_DEF);
|
|
if (cr->cr_ref == 1) {
|
|
mtx_exit(&cr->cr_mtx, MTX_DEF);
|
|
return (cr);
|
|
}
|
|
mtx_exit(&cr->cr_mtx, MTX_DEF);
|
|
newcr = crdup(cr);
|
|
crfree(cr);
|
|
return (newcr);
|
|
}
|
|
|
|
/*
|
|
* Dup cred struct to a new held one.
|
|
*/
|
|
struct ucred *
|
|
crdup(cr)
|
|
struct ucred *cr;
|
|
{
|
|
struct ucred *newcr;
|
|
|
|
MALLOC(newcr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK);
|
|
*newcr = *cr;
|
|
mtx_init(&newcr->cr_mtx, "ucred", MTX_DEF);
|
|
uihold(newcr->cr_uidinfo);
|
|
newcr->cr_ref = 1;
|
|
return (newcr);
|
|
}
|
|
|
|
/*
|
|
* Get login name, if available.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct getlogin_args {
|
|
char *namebuf;
|
|
u_int namelen;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
getlogin(p, uap)
|
|
struct proc *p;
|
|
struct getlogin_args *uap;
|
|
{
|
|
|
|
if (uap->namelen > MAXLOGNAME)
|
|
uap->namelen = MAXLOGNAME;
|
|
return (copyout((caddr_t) p->p_pgrp->pg_session->s_login,
|
|
(caddr_t) uap->namebuf, uap->namelen));
|
|
}
|
|
|
|
/*
|
|
* Set login name.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct setlogin_args {
|
|
char *namebuf;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
setlogin(p, uap)
|
|
struct proc *p;
|
|
struct setlogin_args *uap;
|
|
{
|
|
int error;
|
|
char logintmp[MAXLOGNAME];
|
|
|
|
if ((error = suser_xxx(0, p, PRISON_ROOT)))
|
|
return (error);
|
|
error = copyinstr((caddr_t) uap->namebuf, (caddr_t) logintmp,
|
|
sizeof(logintmp), (size_t *)0);
|
|
if (error == ENAMETOOLONG)
|
|
error = EINVAL;
|
|
else if (!error)
|
|
(void) memcpy(p->p_pgrp->pg_session->s_login, logintmp,
|
|
sizeof(logintmp));
|
|
return (error);
|
|
}
|
|
|
|
void
|
|
setsugid(p)
|
|
struct proc *p;
|
|
{
|
|
p->p_flag |= P_SUGID;
|
|
if (!(p->p_pfsflags & PF_ISUGID))
|
|
p->p_stops = 0;
|
|
}
|
|
|
|
/*
|
|
* Helper function to change the effective uid of a process
|
|
*/
|
|
void
|
|
change_euid(p, euid)
|
|
struct proc *p;
|
|
uid_t euid;
|
|
{
|
|
struct pcred *pc;
|
|
struct uidinfo *uip;
|
|
|
|
pc = p->p_cred;
|
|
/*
|
|
* crcopy is essentially a NOP if ucred has a reference count
|
|
* of 1, which is true if it has already been copied.
|
|
*/
|
|
pc->pc_ucred = crcopy(pc->pc_ucred);
|
|
uip = pc->pc_ucred->cr_uidinfo;
|
|
pc->pc_ucred->cr_uid = euid;
|
|
pc->pc_ucred->cr_uidinfo = uifind(euid);
|
|
uifree(uip);
|
|
}
|
|
|
|
/*
|
|
* Helper function to change the real uid of a process
|
|
*
|
|
* The per-uid process count for this process is transfered from
|
|
* the old uid to the new uid.
|
|
*/
|
|
void
|
|
change_ruid(p, ruid)
|
|
struct proc *p;
|
|
uid_t ruid;
|
|
{
|
|
struct pcred *pc;
|
|
struct uidinfo *uip;
|
|
|
|
pc = p->p_cred;
|
|
(void)chgproccnt(pc->p_uidinfo, -1, 0);
|
|
uip = pc->p_uidinfo;
|
|
/* It is assumed that pcred is not shared between processes */
|
|
pc->p_ruid = ruid;
|
|
pc->p_uidinfo = uifind(ruid);
|
|
(void)chgproccnt(pc->p_uidinfo, 1, 0);
|
|
uifree(uip);
|
|
}
|