include: ssp: fortify <stdlib.h>

The immediately obvious and attractive targets from <stdlib.h> are
arc4random_buf(3) and realpath(3) -- scraping the header didn't reveal
much else of interest.

Reviewed by:	markj
Sponsored by:	Klara, Inc.
Sponsored by:	Stormshield
Differential Revision:	https://reviews.freebsd.org/D45681
This commit is contained in:
Kyle Evans 2024-07-13 00:16:11 -05:00
parent 88276dfbf1
commit d0b7445904
8 changed files with 466 additions and 3 deletions

View File

@ -1,4 +1,4 @@
INCS= poll.h ssp.h stdio.h string.h strings.h unistd.h
INCS= poll.h ssp.h stdio.h stdlib.h string.h strings.h unistd.h
INCSDIR= ${INCLUDEDIR}/ssp
.include <bsd.prog.mk>

53
include/ssp/stdlib.h Normal file
View File

@ -0,0 +1,53 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2024, Klara, Inc.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _SSP_STDLIB_H_
#define _SSP_STDLIB_H_
#include <ssp/ssp.h>
#if __SSP_FORTIFY_LEVEL > 0
#include <limits.h>
__BEGIN_DECLS
__ssp_redirect(void, arc4random_buf, (void *__buf, size_t __len),
(__buf, __len));
__ssp_redirect_raw_impl(char *, realpath, realpath,
(const char *__restrict path, char *__restrict buf))
{
if (__ssp_bos(buf) < PATH_MAX)
__chk_fail();
return (__ssp_real(realpath)(path, buf));
}
__END_DECLS
#endif /* __SSP_FORTIFY_LEVEL > 0 */
#endif /* _SSP_STDLIB_H_ */

View File

@ -69,6 +69,10 @@ typedef struct {
*/
#define RAND_MAX 0x7fffffff
#if !defined(_STANDALONE) && defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0
#include <ssp/stdlib.h>
#endif
__BEGIN_DECLS
#ifdef _XLOCALE_H_
#include <xlocale/_stdlib.h>

View File

@ -35,6 +35,7 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ssp/ssp.h>
#include <sys/types.h>
#include <sys/time.h>
@ -243,7 +244,7 @@ arc4random(void)
}
void
arc4random_buf(void *buf, size_t n)
__ssp_real(arc4random_buf)(void *buf, size_t n)
{
_ARC4_LOCK();
_rs_random_buf(buf, n);

View File

@ -37,6 +37,7 @@
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <ssp/ssp.h>
#include "un-namespace.h"
#include "libc_private.h"
@ -203,7 +204,7 @@ realpath1(const char *path, char *resolved)
}
char *
realpath(const char * __restrict path, char * __restrict resolved)
__ssp_real(realpath)(const char * __restrict path, char * __restrict resolved)
{
char *m, *res;

View File

@ -3,6 +3,7 @@
TESTSDIR:= ${TESTSBASE}/${RELDIR:C/libc\/tests/libc/}
FORTIFY_TCATS+= poll
FORTIFY_TCATS+= stdlib
FORTIFY_TCATS+= stdio
FORTIFY_TCATS+= string
FORTIFY_TCATS+= strings

View File

@ -0,0 +1,383 @@
/* @generated by `generate-fortify-tests.lua "stdlib"` */
#define _FORTIFY_SOURCE 2
#define TMPFILE_SIZE (1024 * 32)
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <poll.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <sysexits.h>
#include <unistd.h>
#include <atf-c.h>
static FILE * __unused
new_fp(size_t __len)
{
static char fpbuf[LINE_MAX];
FILE *fp;
ATF_REQUIRE(__len <= sizeof(fpbuf));
memset(fpbuf, 'A', sizeof(fpbuf) - 1);
fpbuf[sizeof(fpbuf) - 1] = '\0';
fp = fmemopen(fpbuf, sizeof(fpbuf), "rb");
ATF_REQUIRE(fp != NULL);
return (fp);
}
/*
* Create a new symlink to use for readlink(2) style tests, we'll just use a
* random target name to have something interesting to look at.
*/
static const char * __unused
new_symlink(size_t __len)
{
static const char linkname[] = "link";
char target[MAXNAMLEN];
int error;
ATF_REQUIRE(__len <= sizeof(target));
arc4random_buf(target, sizeof(target));
error = unlink(linkname);
ATF_REQUIRE(error == 0 || errno == ENOENT);
error = symlink(target, linkname);
ATF_REQUIRE(error == 0);
return (linkname);
}
/*
* Constructs a tmpfile that we can use for testing read(2) and friends.
*/
static int __unused
new_tmpfile(void)
{
char buf[1024];
ssize_t rv;
size_t written;
int fd;
fd = open("tmpfile", O_RDWR | O_CREAT | O_TRUNC, 0644);
ATF_REQUIRE(fd >= 0);
written = 0;
while (written < TMPFILE_SIZE) {
rv = write(fd, buf, sizeof(buf));
ATF_REQUIRE(rv > 0);
written += rv;
}
ATF_REQUIRE_EQ(0, lseek(fd, 0, SEEK_SET));
return (fd);
}
static void
disable_coredumps(void)
{
struct rlimit rl = { 0 };
if (setrlimit(RLIMIT_CORE, &rl) == -1)
_exit(EX_OSERR);
}
/*
* Replaces stdin with a file that we can actually read from, for tests where
* we want a FILE * or fd that we can get data from.
*/
static void __unused
replace_stdin(void)
{
int fd;
fd = new_tmpfile();
(void)dup2(fd, STDIN_FILENO);
if (fd != STDIN_FILENO)
close(fd);
}
ATF_TC_WITHOUT_HEAD(arc4random_buf_before_end);
ATF_TC_BODY(arc4random_buf_before_end, tc)
{
#define BUF &__stack.__buf
struct {
uint8_t padding_l;
unsigned char __buf[42];
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(__stack.__buf);
const size_t __len = 42 - 1;
const size_t __idx __unused = __len - 1;
arc4random_buf(__stack.__buf, __len);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(arc4random_buf_end);
ATF_TC_BODY(arc4random_buf_end, tc)
{
#define BUF &__stack.__buf
struct {
uint8_t padding_l;
unsigned char __buf[42];
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(__stack.__buf);
const size_t __len = 42;
const size_t __idx __unused = __len - 1;
arc4random_buf(__stack.__buf, __len);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(arc4random_buf_heap_before_end);
ATF_TC_BODY(arc4random_buf_heap_before_end, tc)
{
#define BUF __stack.__buf
struct {
uint8_t padding_l;
unsigned char * __buf;
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(*__stack.__buf) * (42);
const size_t __len = 42 - 1;
const size_t __idx __unused = __len - 1;
__stack.__buf = malloc(__bufsz);
arc4random_buf(__stack.__buf, __len);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(arc4random_buf_heap_end);
ATF_TC_BODY(arc4random_buf_heap_end, tc)
{
#define BUF __stack.__buf
struct {
uint8_t padding_l;
unsigned char * __buf;
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(*__stack.__buf) * (42);
const size_t __len = 42;
const size_t __idx __unused = __len - 1;
__stack.__buf = malloc(__bufsz);
arc4random_buf(__stack.__buf, __len);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(arc4random_buf_heap_after_end);
ATF_TC_BODY(arc4random_buf_heap_after_end, tc)
{
#define BUF __stack.__buf
struct {
uint8_t padding_l;
unsigned char * __buf;
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(*__stack.__buf) * (42);
const size_t __len = 42 + 1;
const size_t __idx __unused = __len - 1;
pid_t __child;
int __status;
__child = fork();
ATF_REQUIRE(__child >= 0);
if (__child > 0)
goto monitor;
/* Child */
disable_coredumps();
__stack.__buf = malloc(__bufsz);
arc4random_buf(__stack.__buf, __len);
_exit(EX_SOFTWARE); /* Should have aborted. */
monitor:
while (waitpid(__child, &__status, 0) != __child) {
ATF_REQUIRE_EQ(EINTR, errno);
}
if (!WIFSIGNALED(__status)) {
switch (WEXITSTATUS(__status)) {
case EX_SOFTWARE:
atf_tc_fail("FORTIFY_SOURCE failed to abort");
break;
case EX_OSERR:
atf_tc_fail("setrlimit(2) failed");
break;
default:
atf_tc_fail("child exited with status %d",
WEXITSTATUS(__status));
}
} else {
ATF_REQUIRE_EQ(SIGABRT, WTERMSIG(__status));
}
#undef BUF
}
ATF_TC_WITHOUT_HEAD(realpath_before_end);
ATF_TC_BODY(realpath_before_end, tc)
{
#define BUF &__stack.__buf
struct {
uint8_t padding_l;
unsigned char __buf[PATH_MAX + 1];
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(__stack.__buf);
const size_t __len = PATH_MAX + 1;
const size_t __idx __unused = __len - 1;
realpath(".", __stack.__buf);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(realpath_end);
ATF_TC_BODY(realpath_end, tc)
{
#define BUF &__stack.__buf
struct {
uint8_t padding_l;
unsigned char __buf[PATH_MAX];
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(__stack.__buf);
const size_t __len = PATH_MAX;
const size_t __idx __unused = __len - 1;
realpath(".", __stack.__buf);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(realpath_heap_before_end);
ATF_TC_BODY(realpath_heap_before_end, tc)
{
#define BUF __stack.__buf
struct {
uint8_t padding_l;
unsigned char * __buf;
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(*__stack.__buf) * (PATH_MAX + 1);
const size_t __len = PATH_MAX + 1;
const size_t __idx __unused = __len - 1;
__stack.__buf = malloc(__bufsz);
realpath(".", __stack.__buf);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(realpath_heap_end);
ATF_TC_BODY(realpath_heap_end, tc)
{
#define BUF __stack.__buf
struct {
uint8_t padding_l;
unsigned char * __buf;
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(*__stack.__buf) * (PATH_MAX);
const size_t __len = PATH_MAX;
const size_t __idx __unused = __len - 1;
__stack.__buf = malloc(__bufsz);
realpath(".", __stack.__buf);
#undef BUF
}
ATF_TC_WITHOUT_HEAD(realpath_heap_after_end);
ATF_TC_BODY(realpath_heap_after_end, tc)
{
#define BUF __stack.__buf
struct {
uint8_t padding_l;
unsigned char * __buf;
uint8_t padding_r;
} __stack;
const size_t __bufsz __unused = sizeof(*__stack.__buf) * (PATH_MAX - 1);
const size_t __len = PATH_MAX - 1;
const size_t __idx __unused = __len - 1;
pid_t __child;
int __status;
__child = fork();
ATF_REQUIRE(__child >= 0);
if (__child > 0)
goto monitor;
/* Child */
disable_coredumps();
__stack.__buf = malloc(__bufsz);
realpath(".", __stack.__buf);
_exit(EX_SOFTWARE); /* Should have aborted. */
monitor:
while (waitpid(__child, &__status, 0) != __child) {
ATF_REQUIRE_EQ(EINTR, errno);
}
if (!WIFSIGNALED(__status)) {
switch (WEXITSTATUS(__status)) {
case EX_SOFTWARE:
atf_tc_fail("FORTIFY_SOURCE failed to abort");
break;
case EX_OSERR:
atf_tc_fail("setrlimit(2) failed");
break;
default:
atf_tc_fail("child exited with status %d",
WEXITSTATUS(__status));
}
} else {
ATF_REQUIRE_EQ(SIGABRT, WTERMSIG(__status));
}
#undef BUF
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, arc4random_buf_before_end);
ATF_TP_ADD_TC(tp, arc4random_buf_end);
ATF_TP_ADD_TC(tp, arc4random_buf_heap_before_end);
ATF_TP_ADD_TC(tp, arc4random_buf_heap_end);
ATF_TP_ADD_TC(tp, arc4random_buf_heap_after_end);
ATF_TP_ADD_TC(tp, realpath_before_end);
ATF_TP_ADD_TC(tp, realpath_end);
ATF_TP_ADD_TC(tp, realpath_heap_before_end);
ATF_TP_ADD_TC(tp, realpath_heap_end);
ATF_TP_ADD_TC(tp, realpath_heap_after_end);
return (atf_no_error());
}

View File

@ -262,6 +262,26 @@ local all_tests = {
]],
},
},
stdlib = {
-- <stdlib.h>
{
func = "arc4random_buf",
arguments = {
"__buf",
"__len",
},
exclude = excludes_stack_overflow,
},
{
func = "realpath",
bufsize = "PATH_MAX",
arguments = {
"\".\"",
"__buf",
},
exclude = excludes_stack_overflow,
},
},
string = {
-- <string.h>
{