freebsd-dev/sys/compat/linux/linux_uid16.c
Tim J. Robbins 1d2d5501f9 Reject negative ngrp arguments in linux_setgroups() and linux_setgroups16();
stops users being able to cause setgroups to clobber the kernel stack by
copying in data past the end of the linux_gidset array.
2003-10-21 11:00:33 +00:00

293 lines
6.7 KiB
C

/*-
* Copyright (c) 2001 The FreeBSD Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <machine/../linux/linux.h>
#include <machine/../linux/linux_proto.h>
#include <compat/linux/linux_util.h>
DUMMY(setfsuid16);
DUMMY(setfsgid16);
DUMMY(getresuid16);
DUMMY(getresgid16);
#define CAST_NOCHG(x) ((x == 0xFFFF) ? -1 : x)
int
linux_chown16(struct thread *td, struct linux_chown16_args *args)
{
char *path;
int error;
LCONVPATHEXIST(td, args->path, &path);
#ifdef DEBUG
if (ldebug(chown16))
printf(ARGS(chown16, "%s, %d, %d"), path, args->uid, args->gid);
#endif
error = kern_chown(td, path, UIO_SYSSPACE, CAST_NOCHG(args->uid),
CAST_NOCHG(args->gid));
LFREEPATH(path);
return (error);
}
int
linux_lchown16(struct thread *td, struct linux_lchown16_args *args)
{
char *path;
int error;
LCONVPATHEXIST(td, args->path, &path);
#ifdef DEBUG
if (ldebug(lchown16))
printf(ARGS(lchown16, "%s, %d, %d"), path, args->uid,
args->gid);
#endif
error = kern_lchown(td, path, UIO_SYSSPACE, CAST_NOCHG(args->uid),
CAST_NOCHG(args->gid));
LFREEPATH(path);
return (error);
}
int
linux_setgroups16(struct thread *td, struct linux_setgroups16_args *args)
{
struct ucred *newcred, *oldcred;
l_gid16_t linux_gidset[NGROUPS];
gid_t *bsd_gidset;
int ngrp, error;
struct proc *p;
#ifdef DEBUG
if (ldebug(setgroups16))
printf(ARGS(setgroups16, "%d, *"), args->gidsetsize);
#endif
ngrp = args->gidsetsize;
if (ngrp < 0 || ngrp >= NGROUPS)
return (EINVAL);
error = copyin(args->gidset, linux_gidset, ngrp * sizeof(l_gid16_t));
if (error)
return (error);
newcred = crget();
p = td->td_proc;
PROC_LOCK(p);
oldcred = p->p_ucred;
/*
* cr_groups[0] holds egid. Setting the whole set from
* the supplied set will cause egid to be changed too.
* Keep cr_groups[0] unchanged to prevent that.
*/
if ((error = suser_cred(oldcred, PRISON_ROOT)) != 0) {
PROC_UNLOCK(p);
crfree(newcred);
return (error);
}
crcopy(newcred, oldcred);
if (ngrp > 0) {
newcred->cr_ngroups = ngrp + 1;
bsd_gidset = newcred->cr_groups;
ngrp--;
while (ngrp >= 0) {
bsd_gidset[ngrp + 1] = linux_gidset[ngrp];
ngrp--;
}
}
else
newcred->cr_ngroups = 1;
setsugid(td->td_proc);
p->p_ucred = newcred;
PROC_UNLOCK(p);
crfree(oldcred);
return (0);
}
int
linux_getgroups16(struct thread *td, struct linux_getgroups16_args *args)
{
struct ucred *cred;
l_gid16_t linux_gidset[NGROUPS];
gid_t *bsd_gidset;
int bsd_gidsetsz, ngrp, error;
#ifdef DEBUG
if (ldebug(getgroups16))
printf(ARGS(getgroups16, "%d, *"), args->gidsetsize);
#endif
cred = td->td_ucred;
bsd_gidset = cred->cr_groups;
bsd_gidsetsz = cred->cr_ngroups - 1;
/*
* cr_groups[0] holds egid. Returning the whole set
* here will cause a duplicate. Exclude cr_groups[0]
* to prevent that.
*/
if ((ngrp = args->gidsetsize) == 0) {
td->td_retval[0] = bsd_gidsetsz;
return (0);
}
if (ngrp < bsd_gidsetsz)
return (EINVAL);
ngrp = 0;
while (ngrp < bsd_gidsetsz) {
linux_gidset[ngrp] = bsd_gidset[ngrp + 1];
ngrp++;
}
error = copyout(linux_gidset, args->gidset, ngrp * sizeof(l_gid16_t));
if (error)
return (error);
td->td_retval[0] = ngrp;
return (0);
}
/*
* The FreeBSD native getgid(2) and getuid(2) also modify td->td_retval[1]
* when COMPAT_43 or COMPAT_SUNOS is defined. This globbers registers that
* are assumed to be preserved. The following lightweight syscalls fixes
* this. See also linux_getpid(2), linux_getgid(2) and linux_getuid(2) in
* linux_misc.c
*
* linux_getgid16() - MP SAFE
* linux_getuid16() - MP SAFE
*/
int
linux_getgid16(struct thread *td, struct linux_getgid16_args *args)
{
td->td_retval[0] = td->td_ucred->cr_rgid;
return (0);
}
int
linux_getuid16(struct thread *td, struct linux_getuid16_args *args)
{
td->td_retval[0] = td->td_ucred->cr_ruid;
return (0);
}
int
linux_getegid16(struct thread *td, struct linux_getegid16_args *args)
{
struct getegid_args bsd;
return (getegid(td, &bsd));
}
int
linux_geteuid16(struct thread *td, struct linux_geteuid16_args *args)
{
struct geteuid_args bsd;
return (geteuid(td, &bsd));
}
int
linux_setgid16(struct thread *td, struct linux_setgid16_args *args)
{
struct setgid_args bsd;
bsd.gid = args->gid;
return (setgid(td, &bsd));
}
int
linux_setuid16(struct thread *td, struct linux_setuid16_args *args)
{
struct setuid_args bsd;
bsd.uid = args->uid;
return (setuid(td, &bsd));
}
int
linux_setregid16(struct thread *td, struct linux_setregid16_args *args)
{
struct setregid_args bsd;
bsd.rgid = CAST_NOCHG(args->rgid);
bsd.egid = CAST_NOCHG(args->egid);
return (setregid(td, &bsd));
}
int
linux_setreuid16(struct thread *td, struct linux_setreuid16_args *args)
{
struct setreuid_args bsd;
bsd.ruid = CAST_NOCHG(args->ruid);
bsd.euid = CAST_NOCHG(args->euid);
return (setreuid(td, &bsd));
}
int
linux_setresgid16(struct thread *td, struct linux_setresgid16_args *args)
{
struct setresgid_args bsd;
bsd.rgid = CAST_NOCHG(args->rgid);
bsd.egid = CAST_NOCHG(args->egid);
bsd.sgid = CAST_NOCHG(args->sgid);
return (setresgid(td, &bsd));
}
int
linux_setresuid16(struct thread *td, struct linux_setresuid16_args *args)
{
struct setresuid_args bsd;
bsd.ruid = CAST_NOCHG(args->ruid);
bsd.euid = CAST_NOCHG(args->euid);
bsd.suid = CAST_NOCHG(args->suid);
return (setresuid(td, &bsd));
}