xref: /xnu-12377.41.6/bsd/tests/stack_chk_tests_sysctl.c (revision bbb1b6f9e71b8cdde6e5cd6f4841f207dee3d828)
1*bbb1b6f9SApple OSS Distributions /*
2*bbb1b6f9SApple OSS Distributions  * Copyright (c) 2021 Apple Inc. All rights reserved.
3*bbb1b6f9SApple OSS Distributions  *
4*bbb1b6f9SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*bbb1b6f9SApple OSS Distributions  *
6*bbb1b6f9SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*bbb1b6f9SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*bbb1b6f9SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*bbb1b6f9SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*bbb1b6f9SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*bbb1b6f9SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*bbb1b6f9SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*bbb1b6f9SApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*bbb1b6f9SApple OSS Distributions  *
15*bbb1b6f9SApple OSS Distributions  * Please obtain a copy of the License at
16*bbb1b6f9SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*bbb1b6f9SApple OSS Distributions  *
18*bbb1b6f9SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*bbb1b6f9SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*bbb1b6f9SApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*bbb1b6f9SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*bbb1b6f9SApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*bbb1b6f9SApple OSS Distributions  * Please see the License for the specific language governing rights and
24*bbb1b6f9SApple OSS Distributions  * limitations under the License.
25*bbb1b6f9SApple OSS Distributions  *
26*bbb1b6f9SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*bbb1b6f9SApple OSS Distributions  */
28*bbb1b6f9SApple OSS Distributions 
29*bbb1b6f9SApple OSS Distributions #if (DEVELOPMENT || DEBUG) && !KASAN
30*bbb1b6f9SApple OSS Distributions 
31*bbb1b6f9SApple OSS Distributions #include <sys/sysctl.h>
32*bbb1b6f9SApple OSS Distributions #include <libkern/stack_protector.h>
33*bbb1b6f9SApple OSS Distributions 
34*bbb1b6f9SApple OSS Distributions __attribute__((noinline))
35*bbb1b6f9SApple OSS Distributions static int
check_for_cookie(size_t len)36*bbb1b6f9SApple OSS Distributions check_for_cookie(size_t len)
37*bbb1b6f9SApple OSS Distributions {
38*bbb1b6f9SApple OSS Distributions 	long buf[4];
39*bbb1b6f9SApple OSS Distributions 	long *search = (long *)(void *)&buf[0];
40*bbb1b6f9SApple OSS Distributions 	size_t n;
41*bbb1b6f9SApple OSS Distributions 
42*bbb1b6f9SApple OSS Distributions 	assert(len < sizeof(buf));
43*bbb1b6f9SApple OSS Distributions 	assert(__stack_chk_guard != 0);
44*bbb1b6f9SApple OSS Distributions 	assert(((uintptr_t)search & (sizeof(long) - 1)) == 0);
45*bbb1b6f9SApple OSS Distributions 
46*bbb1b6f9SApple OSS Distributions 	/* force compiler to insert stack cookie check: */
47*bbb1b6f9SApple OSS Distributions 	memset_s(buf, len, 0, len);
48*bbb1b6f9SApple OSS Distributions 
49*bbb1b6f9SApple OSS Distributions 	/* 32 x sizeof(long) should be plenty to find the cookie: */
50*bbb1b6f9SApple OSS Distributions 	for (n = 0; n < 32; ++n) {
51*bbb1b6f9SApple OSS Distributions 		if (*(search++) == __stack_chk_guard) {
52*bbb1b6f9SApple OSS Distributions 			return 0;
53*bbb1b6f9SApple OSS Distributions 		}
54*bbb1b6f9SApple OSS Distributions 	}
55*bbb1b6f9SApple OSS Distributions 
56*bbb1b6f9SApple OSS Distributions 	return ESRCH;
57*bbb1b6f9SApple OSS Distributions }
58*bbb1b6f9SApple OSS Distributions 
59*bbb1b6f9SApple OSS Distributions static int
60*bbb1b6f9SApple OSS Distributions sysctl_run_stack_chk_tests SYSCTL_HANDLER_ARGS
61*bbb1b6f9SApple OSS Distributions {
62*bbb1b6f9SApple OSS Distributions 	#pragma unused(arg1, arg2, oidp)
63*bbb1b6f9SApple OSS Distributions 
64*bbb1b6f9SApple OSS Distributions 	unsigned int dummy = 0;
65*bbb1b6f9SApple OSS Distributions 	int error, changed = 0, kr;
66*bbb1b6f9SApple OSS Distributions 	error = sysctl_io_number(req, 0, sizeof(dummy), &dummy, &changed);
67*bbb1b6f9SApple OSS Distributions 	if (error || !changed) {
68*bbb1b6f9SApple OSS Distributions 		return error;
69*bbb1b6f9SApple OSS Distributions 	}
70*bbb1b6f9SApple OSS Distributions 
71*bbb1b6f9SApple OSS Distributions 	kr = check_for_cookie(3);
72*bbb1b6f9SApple OSS Distributions 	return kr;
73*bbb1b6f9SApple OSS Distributions }
74*bbb1b6f9SApple OSS Distributions 
75*bbb1b6f9SApple OSS Distributions SYSCTL_PROC(_kern, OID_AUTO, run_stack_chk_tests,
76*bbb1b6f9SApple OSS Distributions     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
77*bbb1b6f9SApple OSS Distributions     0, 0, sysctl_run_stack_chk_tests, "I", "");
78*bbb1b6f9SApple OSS Distributions 
79*bbb1b6f9SApple OSS Distributions #endif /* (DEVELOPMENT || DEBUG) && !KASAN */
80