1*4d495c6eSApple OSS Distributions /*
2*4d495c6eSApple OSS Distributions * Copyright (c) 2021 Apple Inc. All rights reserved.
3*4d495c6eSApple OSS Distributions *
4*4d495c6eSApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*4d495c6eSApple OSS Distributions *
6*4d495c6eSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*4d495c6eSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*4d495c6eSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*4d495c6eSApple OSS Distributions * compliance with the License. The rights granted to you under the License
10*4d495c6eSApple OSS Distributions * may not be used to create, or enable the creation or redistribution of,
11*4d495c6eSApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to
12*4d495c6eSApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any
13*4d495c6eSApple OSS Distributions * terms of an Apple operating system software license agreement.
14*4d495c6eSApple OSS Distributions *
15*4d495c6eSApple OSS Distributions * Please obtain a copy of the License at
16*4d495c6eSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*4d495c6eSApple OSS Distributions *
18*4d495c6eSApple OSS Distributions * The Original Code and all software distributed under the License are
19*4d495c6eSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*4d495c6eSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*4d495c6eSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*4d495c6eSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*4d495c6eSApple OSS Distributions * Please see the License for the specific language governing rights and
24*4d495c6eSApple OSS Distributions * limitations under the License.
25*4d495c6eSApple OSS Distributions *
26*4d495c6eSApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*4d495c6eSApple OSS Distributions */
28*4d495c6eSApple OSS Distributions
29*4d495c6eSApple OSS Distributions #if (DEVELOPMENT || DEBUG) && !KASAN
30*4d495c6eSApple OSS Distributions
31*4d495c6eSApple OSS Distributions #include <sys/sysctl.h>
32*4d495c6eSApple OSS Distributions #include <libkern/stack_protector.h>
33*4d495c6eSApple OSS Distributions
34*4d495c6eSApple OSS Distributions __attribute__((noinline))
35*4d495c6eSApple OSS Distributions static int
check_for_cookie(size_t len)36*4d495c6eSApple OSS Distributions check_for_cookie(size_t len)
37*4d495c6eSApple OSS Distributions {
38*4d495c6eSApple OSS Distributions long buf[4];
39*4d495c6eSApple OSS Distributions long *search = (long *)(void *)&buf[0];
40*4d495c6eSApple OSS Distributions size_t n;
41*4d495c6eSApple OSS Distributions
42*4d495c6eSApple OSS Distributions assert(len < sizeof(buf));
43*4d495c6eSApple OSS Distributions assert(__stack_chk_guard != 0);
44*4d495c6eSApple OSS Distributions assert(((uintptr_t)search & (sizeof(long) - 1)) == 0);
45*4d495c6eSApple OSS Distributions
46*4d495c6eSApple OSS Distributions /* force compiler to insert stack cookie check: */
47*4d495c6eSApple OSS Distributions memset_s(buf, len, 0, len);
48*4d495c6eSApple OSS Distributions
49*4d495c6eSApple OSS Distributions /* 32 x sizeof(long) should be plenty to find the cookie: */
50*4d495c6eSApple OSS Distributions for (n = 0; n < 32; ++n) {
51*4d495c6eSApple OSS Distributions if (*(search++) == __stack_chk_guard) {
52*4d495c6eSApple OSS Distributions return 0;
53*4d495c6eSApple OSS Distributions }
54*4d495c6eSApple OSS Distributions }
55*4d495c6eSApple OSS Distributions
56*4d495c6eSApple OSS Distributions return ESRCH;
57*4d495c6eSApple OSS Distributions }
58*4d495c6eSApple OSS Distributions
59*4d495c6eSApple OSS Distributions static int
60*4d495c6eSApple OSS Distributions sysctl_run_stack_chk_tests SYSCTL_HANDLER_ARGS
61*4d495c6eSApple OSS Distributions {
62*4d495c6eSApple OSS Distributions #pragma unused(arg1, arg2, oidp)
63*4d495c6eSApple OSS Distributions
64*4d495c6eSApple OSS Distributions unsigned int dummy = 0;
65*4d495c6eSApple OSS Distributions int error, changed = 0, kr;
66*4d495c6eSApple OSS Distributions error = sysctl_io_number(req, 0, sizeof(dummy), &dummy, &changed);
67*4d495c6eSApple OSS Distributions if (error || !changed) {
68*4d495c6eSApple OSS Distributions return error;
69*4d495c6eSApple OSS Distributions }
70*4d495c6eSApple OSS Distributions
71*4d495c6eSApple OSS Distributions kr = check_for_cookie(3);
72*4d495c6eSApple OSS Distributions return kr;
73*4d495c6eSApple OSS Distributions }
74*4d495c6eSApple OSS Distributions
75*4d495c6eSApple OSS Distributions SYSCTL_PROC(_kern, OID_AUTO, run_stack_chk_tests,
76*4d495c6eSApple OSS Distributions CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
77*4d495c6eSApple OSS Distributions 0, 0, sysctl_run_stack_chk_tests, "I", "");
78*4d495c6eSApple OSS Distributions
79*4d495c6eSApple OSS Distributions #endif /* (DEVELOPMENT || DEBUG) && !KASAN */
80