freebsd-dev/sys/kern/subr_capability.c
Pawel Jakub Dawidek 5a1983cc41 Fix panic in cap_rights_is_valid() when invalid rights are provided -
the right_to_index() function should assert correctness in this case.

Improve other assertions.

Reported by:	pho
Tested by:	pho
2013-09-07 19:03:16 +00:00

299 lines
7.0 KiB
C

/*-
* Copyright (c) 2013 FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* 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("$FreeBSD$");
#ifdef _KERNEL
#include <sys/types.h>
#include <sys/capability.h>
#include <sys/systm.h>
#include <machine/stdarg.h>
#else /* !_KERNEL */
#include <sys/types.h>
#include <sys/capability.h>
#include <assert.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#endif
#ifdef _KERNEL
#define assert(exp) KASSERT((exp), ("%s:%u", __func__, __LINE__))
#endif
#define CAPARSIZE_MIN (CAP_RIGHTS_VERSION_00 + 2)
#define CAPARSIZE_MAX (CAP_RIGHTS_VERSION + 2)
static __inline int
right_to_index(uint64_t right)
{
static const int bit2idx[] = {
-1, 0, 1, -1, 2, -1, -1, -1, 3, -1, -1, -1, -1, -1, -1, -1,
4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
int idx;
idx = CAPIDXBIT(right);
assert(idx >= 0 && idx < sizeof(bit2idx) / sizeof(bit2idx[0]));
return (bit2idx[idx]);
}
static void
cap_rights_vset(cap_rights_t *rights, va_list ap)
{
uint64_t right;
int i, n;
assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
n = CAPARSIZE(rights);
assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
for (;;) {
right = (uint64_t)va_arg(ap, unsigned long long);
if (right == 0)
break;
assert(CAPRVER(right) == 0);
i = right_to_index(right);
assert(i >= 0);
assert(i < n);
assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
rights->cr_rights[i] |= right;
assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
}
}
static void
cap_rights_vclear(cap_rights_t *rights, va_list ap)
{
uint64_t right;
int i, n;
assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
n = CAPARSIZE(rights);
assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
for (;;) {
right = (uint64_t)va_arg(ap, unsigned long long);
if (right == 0)
break;
assert(CAPRVER(right) == 0);
i = right_to_index(right);
assert(i >= 0);
assert(i < n);
assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
rights->cr_rights[i] &= ~(right & 0x01FFFFFFFFFFFFFFULL);
assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
}
}
static bool
cap_rights_is_vset(const cap_rights_t *rights, va_list ap)
{
uint64_t right;
int i, n;
assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
n = CAPARSIZE(rights);
assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
for (;;) {
right = (uint64_t)va_arg(ap, unsigned long long);
if (right == 0)
break;
assert(CAPRVER(right) == 0);
i = right_to_index(right);
assert(i >= 0);
assert(i < n);
assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
if ((rights->cr_rights[i] & right) != right)
return (false);
}
return (true);
}
cap_rights_t *
__cap_rights_init(int version, cap_rights_t *rights, ...)
{
unsigned int n;
va_list ap;
assert(version == CAP_RIGHTS_VERSION_00);
n = version + 2;
assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
memset(rights->cr_rights, 0, sizeof(rights->cr_rights[0]) * n);
CAP_NONE(rights);
va_start(ap, rights);
cap_rights_vset(rights, ap);
va_end(ap);
return (rights);
}
void
__cap_rights_set(cap_rights_t *rights, ...)
{
va_list ap;
assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
va_start(ap, rights);
cap_rights_vset(rights, ap);
va_end(ap);
}
void
__cap_rights_clear(cap_rights_t *rights, ...)
{
va_list ap;
assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
va_start(ap, rights);
cap_rights_vclear(rights, ap);
va_end(ap);
}
bool
__cap_rights_is_set(const cap_rights_t *rights, ...)
{
va_list ap;
bool ret;
assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
va_start(ap, rights);
ret = cap_rights_is_vset(rights, ap);
va_end(ap);
return (ret);
}
bool
cap_rights_is_valid(const cap_rights_t *rights)
{
cap_rights_t allrights;
int i, j;
if (CAPVER(rights) != CAP_RIGHTS_VERSION_00)
return (false);
if (CAPARSIZE(rights) < CAPARSIZE_MIN ||
CAPARSIZE(rights) > CAPARSIZE_MAX) {
return (false);
}
CAP_ALL(&allrights);
if (!cap_rights_contains(&allrights, rights))
return (false);
for (i = 0; i < CAPARSIZE(rights); i++) {
j = right_to_index(rights->cr_rights[i]);
if (i != j)
return (false);
if (i > 0) {
if (CAPRVER(rights->cr_rights[i]) != 0)
return (false);
}
}
return (true);
}
void
cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src)
{
unsigned int i, n;
assert(CAPVER(dst) == CAP_RIGHTS_VERSION_00);
assert(CAPVER(src) == CAP_RIGHTS_VERSION_00);
assert(CAPVER(dst) == CAPVER(src));
assert(cap_rights_is_valid(src));
assert(cap_rights_is_valid(dst));
n = CAPARSIZE(dst);
assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
for (i = 0; i < n; i++)
dst->cr_rights[i] |= src->cr_rights[i];
assert(cap_rights_is_valid(src));
assert(cap_rights_is_valid(dst));
}
void
cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src)
{
unsigned int i, n;
assert(CAPVER(dst) == CAP_RIGHTS_VERSION_00);
assert(CAPVER(src) == CAP_RIGHTS_VERSION_00);
assert(CAPVER(dst) == CAPVER(src));
assert(cap_rights_is_valid(src));
assert(cap_rights_is_valid(dst));
n = CAPARSIZE(dst);
assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
for (i = 0; i < n; i++) {
dst->cr_rights[i] &=
~(src->cr_rights[i] & 0x01FFFFFFFFFFFFFFULL);
}
assert(cap_rights_is_valid(src));
assert(cap_rights_is_valid(dst));
}
bool
cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little)
{
unsigned int i, n;
assert(CAPVER(big) == CAP_RIGHTS_VERSION_00);
assert(CAPVER(little) == CAP_RIGHTS_VERSION_00);
assert(CAPVER(big) == CAPVER(little));
n = CAPARSIZE(big);
assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
for (i = 0; i < n; i++) {
if ((big->cr_rights[i] & little->cr_rights[i]) !=
little->cr_rights[i]) {
return (false);
}
}
return (true);
}