.. | .. |
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| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
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1 | 2 | /* |
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2 | 3 | * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com> |
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3 | | - * |
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4 | | - * This program is free software; you can redistribute it and/or |
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5 | | - * modify it under the terms of the GNU General Public License |
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6 | | - * as published by the Free Software Foundation; either version 2 |
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7 | | - * of the License, or (at your option) any later version. |
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8 | | - * |
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9 | | - * This program is distributed in the hope that it will be useful, |
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10 | | - * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 | | - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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12 | | - * GNU General Public License for more details. |
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13 | | - * |
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14 | | - * You should have received a copy of the GNU General Public License |
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15 | | - * along with this program; if not, see <http://www.gnu.org/licenses/>. |
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16 | 4 | */ |
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17 | 5 | |
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18 | 6 | /* |
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.. | .. |
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64 | 52 | */ |
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65 | 53 | static int shadow_leak_ctor(void *obj, void *shadow_data, void *ctor_data) |
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66 | 54 | { |
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67 | | - void **shadow_leak = shadow_data; |
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68 | | - void *leak = ctor_data; |
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| 55 | + int **shadow_leak = shadow_data; |
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| 56 | + int **leak = ctor_data; |
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69 | 57 | |
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70 | | - *shadow_leak = leak; |
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| 58 | + if (!ctor_data) |
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| 59 | + return -EINVAL; |
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| 60 | + |
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| 61 | + *shadow_leak = *leak; |
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71 | 62 | return 0; |
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72 | 63 | } |
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73 | 64 | |
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74 | | -struct dummy *livepatch_fix1_dummy_alloc(void) |
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| 65 | +static struct dummy *livepatch_fix1_dummy_alloc(void) |
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75 | 66 | { |
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76 | 67 | struct dummy *d; |
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77 | | - void *leak; |
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| 68 | + int *leak; |
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| 69 | + int **shadow_leak; |
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78 | 70 | |
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79 | 71 | d = kzalloc(sizeof(*d), GFP_KERNEL); |
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80 | 72 | if (!d) |
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.. | .. |
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88 | 80 | * variable. A patched dummy_free routine can later fetch this |
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89 | 81 | * pointer to handle resource release. |
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90 | 82 | */ |
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91 | | - leak = kzalloc(sizeof(int), GFP_KERNEL); |
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92 | | - if (!leak) { |
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93 | | - kfree(d); |
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94 | | - return NULL; |
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95 | | - } |
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| 83 | + leak = kzalloc(sizeof(*leak), GFP_KERNEL); |
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| 84 | + if (!leak) |
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| 85 | + goto err_leak; |
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96 | 86 | |
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97 | | - klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL, |
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98 | | - shadow_leak_ctor, leak); |
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| 87 | + shadow_leak = klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL, |
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| 88 | + shadow_leak_ctor, &leak); |
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| 89 | + if (!shadow_leak) { |
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| 90 | + pr_err("%s: failed to allocate shadow variable for the leaking pointer: dummy @ %p, leak @ %p\n", |
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| 91 | + __func__, d, leak); |
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| 92 | + goto err_shadow; |
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| 93 | + } |
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99 | 94 | |
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100 | 95 | pr_info("%s: dummy @ %p, expires @ %lx\n", |
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101 | 96 | __func__, d, d->jiffies_expire); |
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102 | 97 | |
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103 | 98 | return d; |
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| 99 | + |
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| 100 | +err_shadow: |
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| 101 | + kfree(leak); |
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| 102 | +err_leak: |
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| 103 | + kfree(d); |
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| 104 | + return NULL; |
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104 | 105 | } |
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105 | 106 | |
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106 | 107 | static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data) |
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107 | 108 | { |
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108 | 109 | void *d = obj; |
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109 | | - void **shadow_leak = shadow_data; |
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| 110 | + int **shadow_leak = shadow_data; |
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110 | 111 | |
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111 | 112 | kfree(*shadow_leak); |
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112 | 113 | pr_info("%s: dummy @ %p, prevented leak @ %p\n", |
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113 | 114 | __func__, d, *shadow_leak); |
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114 | 115 | } |
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115 | 116 | |
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116 | | -void livepatch_fix1_dummy_free(struct dummy *d) |
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| 117 | +static void livepatch_fix1_dummy_free(struct dummy *d) |
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117 | 118 | { |
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118 | | - void **shadow_leak; |
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| 119 | + int **shadow_leak; |
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119 | 120 | |
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120 | 121 | /* |
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121 | 122 | * Patch: fetch the saved SV_LEAK shadow variable, detach and |
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.. | .. |
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157 | 158 | |
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158 | 159 | static int livepatch_shadow_fix1_init(void) |
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159 | 160 | { |
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160 | | - int ret; |
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161 | | - |
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162 | | - ret = klp_register_patch(&patch); |
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163 | | - if (ret) |
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164 | | - return ret; |
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165 | | - ret = klp_enable_patch(&patch); |
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166 | | - if (ret) { |
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167 | | - WARN_ON(klp_unregister_patch(&patch)); |
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168 | | - return ret; |
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169 | | - } |
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170 | | - return 0; |
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| 161 | + return klp_enable_patch(&patch); |
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171 | 162 | } |
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172 | 163 | |
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173 | 164 | static void livepatch_shadow_fix1_exit(void) |
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174 | 165 | { |
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175 | 166 | /* Cleanup any existing SV_LEAK shadow variables */ |
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176 | 167 | klp_shadow_free_all(SV_LEAK, livepatch_fix1_dummy_leak_dtor); |
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177 | | - |
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178 | | - WARN_ON(klp_unregister_patch(&patch)); |
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179 | 168 | } |
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180 | 169 | |
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181 | 170 | module_init(livepatch_shadow_fix1_init); |
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