1 /* 2 * Copyright (c) 2020 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29 #if DEVELOPMENT || DEBUG 30 #if __has_feature(ptrauth_calls) 31 32 #include <sys/errno.h> 33 #include <sys/sysctl.h> 34 #include <sys/ubc.h> 35 #include <kern/kalloc.h> 36 #include <libkern/libkern.h> 37 #include <pexpert/pexpert.h> 38 39 40 #include <mach/task.h> 41 #include <kern/task.h> 42 #include <sys/ubc_internal.h> 43 44 extern kern_return_t ptrauth_data_tests(void); 45 46 /* 47 * Given an existing PAC pointer (ptr), its declaration type (decl), the (key) 48 * used to sign it and the string discriminator (discr), extract the raw pointer 49 * along with the signature and compare it with one computed on the fly 50 * via ptrauth_sign_unauthenticated(). 51 * 52 * If the two mismatch, return an error and fail the test. 53 */ 54 #define VALIDATE_PTR(decl, ptr, key, discr) { \ 55 decl raw = *(decl *)(uintptr_t)&(ptr); \ 56 decl cmp = ptrauth_sign_unauthenticated(ptr, key, \ 57 ptrauth_blend_discriminator(&ptr, ptrauth_string_discriminator(discr))); \ 58 if (cmp != raw) { \ 59 printf("kern.run_pac_test: %s (%s) (discr=%s) is not signed as expected (%p vs %p)\n", #decl, #ptr, #discr, raw, cmp); \ 60 kr = EINVAL; \ 61 } \ 62 } 63 64 /* 65 * Allocate the containing structure, and store a pointer to the desired member, 66 * which should be subject to pointer signing. 67 */ 68 #define ALLOC_VALIDATE_DATA_PTR(structure, decl, member, discr) { \ 69 __typed_allocators_ignore_push \ 70 structure *tmp = kalloc_data(sizeof(structure), Z_WAITOK | Z_ZERO); \ 71 if (!tmp) return ENOMEM; \ 72 tmp->member = (void*)0xffffffff41414141; \ 73 VALIDATE_DATA_PTR(decl, tmp->member, discr) \ 74 kfree_data(tmp, sizeof(structure)); \ 75 __typed_allocators_ignore_pop \ 76 } 77 78 #define VALIDATE_DATA_PTR(decl, ptr, discr) VALIDATE_PTR(decl, ptr, ptrauth_key_process_independent_data, discr) 79 80 /* 81 * Validate that a pointer that is supposed to be signed, is, and that the signature 82 * matches based on signing key, location and discriminator 83 */ 84 static int 85 sysctl_run_ptrauth_data_tests SYSCTL_HANDLER_ARGS 86 { 87 #pragma unused(arg1, arg2, oidp) 88 89 unsigned int dummy; 90 int error, changed, kr; 91 error = sysctl_io_number(req, 0, sizeof(dummy), &dummy, &changed); 92 if (error || !changed) { 93 return error; 94 } 95 96 /* proc_t */ 97 ALLOC_VALIDATE_DATA_PTR(struct proc, struct proc *, p_pptr, "proc.p_pptr"); 98 ALLOC_VALIDATE_DATA_PTR(struct proc, struct vnode *, p_textvp, "proc.p_textvp"); 99 ALLOC_VALIDATE_DATA_PTR(struct proc, struct pgrp *, p_pgrp.__smr_ptr, "proc.p_pgrp"); 100 101 /* The rest of the tests live in osfmk/ */ 102 kr = ptrauth_data_tests(); 103 104 if (error == 0) { 105 error = mach_to_bsd_errno(kr); 106 } 107 108 return kr; 109 } 110 111 SYSCTL_PROC(_kern, OID_AUTO, run_ptrauth_data_tests, 112 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED, 113 0, 0, sysctl_run_ptrauth_data_tests, "I", ""); 114 115 #endif /* __has_feature(ptrauth_calls) */ 116 #endif /* DEVELOPMENT || DEBUG */ 117