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e886bf9d | 1 | // SPDX-License-Identifier: GPL-2.0 |
0b24becc | 2 | /* |
11cd3cd6 | 3 | * This file contains common generic and tag-based KASAN error reporting code. |
0b24becc AR |
4 | * |
5 | * Copyright (c) 2014 Samsung Electronics Co., Ltd. | |
2baf9e89 | 6 | * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> |
0b24becc | 7 | * |
5d0926ef | 8 | * Some code borrowed from https://github.com/xairy/kasan-prototype by |
5f21f3a8 | 9 | * Andrey Konovalov <andreyknvl@gmail.com> |
0b24becc AR |
10 | * |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | * | |
15 | */ | |
16 | ||
b0845ce5 | 17 | #include <linux/bitops.h> |
4f40c6e5 | 18 | #include <linux/ftrace.h> |
b0845ce5 | 19 | #include <linux/init.h> |
0b24becc AR |
20 | #include <linux/kernel.h> |
21 | #include <linux/mm.h> | |
22 | #include <linux/printk.h> | |
23 | #include <linux/sched.h> | |
24 | #include <linux/slab.h> | |
cd11016e | 25 | #include <linux/stackdepot.h> |
0b24becc AR |
26 | #include <linux/stacktrace.h> |
27 | #include <linux/string.h> | |
28 | #include <linux/types.h> | |
29 | #include <linux/kasan.h> | |
527f215b | 30 | #include <linux/module.h> |
e8969219 | 31 | #include <linux/sched/task_stack.h> |
4fba3758 | 32 | #include <linux/uaccess.h> |
0b24becc | 33 | |
bebf56a1 AR |
34 | #include <asm/sections.h> |
35 | ||
83c4e7a0 PA |
36 | #include <kunit/test.h> |
37 | ||
0b24becc | 38 | #include "kasan.h" |
0316bec2 | 39 | #include "../slab.h" |
0b24becc AR |
40 | |
41 | /* Shadow layout customization. */ | |
42 | #define SHADOW_BYTES_PER_BLOCK 1 | |
43 | #define SHADOW_BLOCKS_PER_ROW 16 | |
44 | #define SHADOW_BYTES_PER_ROW (SHADOW_BLOCKS_PER_ROW * SHADOW_BYTES_PER_BLOCK) | |
45 | #define SHADOW_ROWS_AROUND_ADDR 2 | |
46 | ||
11cd3cd6 | 47 | static unsigned long kasan_flags; |
0b24becc | 48 | |
11cd3cd6 AK |
49 | #define KASAN_BIT_REPORTED 0 |
50 | #define KASAN_BIT_MULTI_SHOT 1 | |
5e82cd12 | 51 | |
11cd3cd6 | 52 | bool kasan_save_enable_multi_shot(void) |
0b24becc | 53 | { |
11cd3cd6 | 54 | return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); |
5e82cd12 | 55 | } |
11cd3cd6 | 56 | EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot); |
5e82cd12 | 57 | |
11cd3cd6 | 58 | void kasan_restore_multi_shot(bool enabled) |
5e82cd12 | 59 | { |
11cd3cd6 AK |
60 | if (!enabled) |
61 | clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); | |
5e82cd12 | 62 | } |
11cd3cd6 | 63 | EXPORT_SYMBOL_GPL(kasan_restore_multi_shot); |
5e82cd12 | 64 | |
11cd3cd6 | 65 | static int __init kasan_set_multi_shot(char *str) |
7d418f7b | 66 | { |
11cd3cd6 AK |
67 | set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); |
68 | return 1; | |
7d418f7b | 69 | } |
11cd3cd6 | 70 | __setup("kasan_multi_shot", kasan_set_multi_shot); |
7d418f7b | 71 | |
121e8f81 | 72 | static void print_error_description(struct kasan_access_info *info) |
5e82cd12 | 73 | { |
7f0a84c2 | 74 | pr_err("BUG: KASAN: %s in %pS\n", |
121e8f81 | 75 | get_bug_type(info), (void *)info->ip); |
6424f6bb | 76 | pr_err("%s of size %zu at addr %px by task %s/%d\n", |
7d418f7b | 77 | info->is_write ? "Write" : "Read", info->access_size, |
7f0a84c2 | 78 | info->access_addr, current->comm, task_pid_nr(current)); |
0b24becc AR |
79 | } |
80 | ||
7e088978 AR |
81 | static DEFINE_SPINLOCK(report_lock); |
82 | ||
11cd3cd6 | 83 | static void start_report(unsigned long *flags) |
7e088978 AR |
84 | { |
85 | /* | |
86 | * Make sure we don't end up in loop. | |
87 | */ | |
88 | kasan_disable_current(); | |
89 | spin_lock_irqsave(&report_lock, *flags); | |
90 | pr_err("==================================================================\n"); | |
91 | } | |
92 | ||
11cd3cd6 | 93 | static void end_report(unsigned long *flags) |
7e088978 AR |
94 | { |
95 | pr_err("==================================================================\n"); | |
96 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); | |
97 | spin_unlock_irqrestore(&report_lock, *flags); | |
be4f1ae9 | 98 | if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) { |
1d2252fa KC |
99 | /* |
100 | * This thread may hit another WARN() in the panic path. | |
101 | * Resetting this prevents additional WARN() from panicking the | |
102 | * system on this thread. Other threads are blocked by the | |
103 | * panic_mutex in panic(). | |
104 | */ | |
105 | panic_on_warn = 0; | |
5c5c1f36 | 106 | panic("panic_on_warn set ...\n"); |
1d2252fa | 107 | } |
7e088978 AR |
108 | kasan_enable_current(); |
109 | } | |
110 | ||
26e760c9 WW |
111 | static void print_stack(depot_stack_handle_t stack) |
112 | { | |
113 | unsigned long *entries; | |
114 | unsigned int nr_entries; | |
115 | ||
116 | nr_entries = stack_depot_fetch(stack, &entries); | |
117 | stack_trace_print(entries, nr_entries, 0); | |
118 | } | |
119 | ||
b6b72f49 | 120 | static void print_track(struct kasan_track *track, const char *prefix) |
7ed2f9e6 | 121 | { |
b6b72f49 | 122 | pr_err("%s by task %u:\n", prefix, track->pid); |
cd11016e | 123 | if (track->stack) { |
26e760c9 | 124 | print_stack(track->stack); |
cd11016e AP |
125 | } else { |
126 | pr_err("(stack is not available)\n"); | |
127 | } | |
7ed2f9e6 AP |
128 | } |
129 | ||
ae8f06b3 | 130 | struct page *kasan_addr_to_page(const void *addr) |
db429f16 AK |
131 | { |
132 | if ((addr >= (void *)PAGE_OFFSET) && | |
133 | (addr < high_memory)) | |
134 | return virt_to_head_page(addr); | |
135 | return NULL; | |
136 | } | |
137 | ||
0c06f1f8 AK |
138 | static void describe_object_addr(struct kmem_cache *cache, void *object, |
139 | const void *addr) | |
7ed2f9e6 | 140 | { |
0c06f1f8 AK |
141 | unsigned long access_addr = (unsigned long)addr; |
142 | unsigned long object_addr = (unsigned long)object; | |
143 | const char *rel_type; | |
144 | int rel_bytes; | |
7ed2f9e6 | 145 | |
6424f6bb | 146 | pr_err("The buggy address belongs to the object at %px\n" |
0c06f1f8 AK |
147 | " which belongs to the cache %s of size %d\n", |
148 | object, cache->name, cache->object_size); | |
47b5c2a0 | 149 | |
0c06f1f8 | 150 | if (!addr) |
7ed2f9e6 | 151 | return; |
b3cbd9bf | 152 | |
0c06f1f8 AK |
153 | if (access_addr < object_addr) { |
154 | rel_type = "to the left"; | |
155 | rel_bytes = object_addr - access_addr; | |
156 | } else if (access_addr >= object_addr + cache->object_size) { | |
157 | rel_type = "to the right"; | |
158 | rel_bytes = access_addr - (object_addr + cache->object_size); | |
159 | } else { | |
160 | rel_type = "inside"; | |
161 | rel_bytes = access_addr - object_addr; | |
162 | } | |
163 | ||
164 | pr_err("The buggy address is located %d bytes %s of\n" | |
6424f6bb | 165 | " %d-byte region [%px, %px)\n", |
0c06f1f8 AK |
166 | rel_bytes, rel_type, cache->object_size, (void *)object_addr, |
167 | (void *)(object_addr + cache->object_size)); | |
168 | } | |
169 | ||
170 | static void describe_object(struct kmem_cache *cache, void *object, | |
ae8f06b3 | 171 | const void *addr, u8 tag) |
0c06f1f8 AK |
172 | { |
173 | struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object); | |
174 | ||
175 | if (cache->flags & SLAB_KASAN) { | |
ae8f06b3 WW |
176 | struct kasan_track *free_track; |
177 | ||
0c06f1f8 | 178 | print_track(&alloc_info->alloc_track, "Allocated"); |
b1938599 | 179 | pr_err("\n"); |
ae8f06b3 | 180 | free_track = kasan_get_free_track(cache, object, tag); |
e4b7818b WW |
181 | if (free_track) { |
182 | print_track(free_track, "Freed"); | |
183 | pr_err("\n"); | |
184 | } | |
26e760c9 WW |
185 | |
186 | #ifdef CONFIG_KASAN_GENERIC | |
187 | if (alloc_info->aux_stack[0]) { | |
188 | pr_err("Last call_rcu():\n"); | |
189 | print_stack(alloc_info->aux_stack[0]); | |
190 | pr_err("\n"); | |
191 | } | |
192 | if (alloc_info->aux_stack[1]) { | |
193 | pr_err("Second to last call_rcu():\n"); | |
194 | print_stack(alloc_info->aux_stack[1]); | |
195 | pr_err("\n"); | |
196 | } | |
197 | #endif | |
0c06f1f8 AK |
198 | } |
199 | ||
200 | describe_object_addr(cache, object, addr); | |
7ed2f9e6 | 201 | } |
7ed2f9e6 | 202 | |
11cd3cd6 AK |
203 | static inline bool kernel_or_module_addr(const void *addr) |
204 | { | |
205 | if (addr >= (void *)_stext && addr < (void *)_end) | |
206 | return true; | |
207 | if (is_module_address((unsigned long)addr)) | |
208 | return true; | |
209 | return false; | |
210 | } | |
211 | ||
212 | static inline bool init_task_stack_addr(const void *addr) | |
213 | { | |
214 | return addr >= (void *)&init_thread_union.stack && | |
215 | (addr <= (void *)&init_thread_union.stack + | |
216 | sizeof(init_thread_union.stack)); | |
217 | } | |
218 | ||
e8969219 ME |
219 | static bool __must_check tokenize_frame_descr(const char **frame_descr, |
220 | char *token, size_t max_tok_len, | |
221 | unsigned long *value) | |
222 | { | |
223 | const char *sep = strchr(*frame_descr, ' '); | |
224 | ||
225 | if (sep == NULL) | |
226 | sep = *frame_descr + strlen(*frame_descr); | |
227 | ||
228 | if (token != NULL) { | |
229 | const size_t tok_len = sep - *frame_descr; | |
230 | ||
231 | if (tok_len + 1 > max_tok_len) { | |
232 | pr_err("KASAN internal error: frame description too long: %s\n", | |
233 | *frame_descr); | |
234 | return false; | |
235 | } | |
236 | ||
237 | /* Copy token (+ 1 byte for '\0'). */ | |
238 | strlcpy(token, *frame_descr, tok_len + 1); | |
239 | } | |
240 | ||
241 | /* Advance frame_descr past separator. */ | |
242 | *frame_descr = sep + 1; | |
243 | ||
244 | if (value != NULL && kstrtoul(token, 10, value)) { | |
245 | pr_err("KASAN internal error: not a valid number: %s\n", token); | |
246 | return false; | |
247 | } | |
248 | ||
249 | return true; | |
250 | } | |
251 | ||
252 | static void print_decoded_frame_descr(const char *frame_descr) | |
253 | { | |
254 | /* | |
255 | * We need to parse the following string: | |
256 | * "n alloc_1 alloc_2 ... alloc_n" | |
257 | * where alloc_i looks like | |
258 | * "offset size len name" | |
259 | * or "offset size len name:line". | |
260 | */ | |
261 | ||
262 | char token[64]; | |
263 | unsigned long num_objects; | |
264 | ||
265 | if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), | |
266 | &num_objects)) | |
267 | return; | |
268 | ||
269 | pr_err("\n"); | |
270 | pr_err("this frame has %lu %s:\n", num_objects, | |
271 | num_objects == 1 ? "object" : "objects"); | |
272 | ||
273 | while (num_objects--) { | |
274 | unsigned long offset; | |
275 | unsigned long size; | |
276 | ||
277 | /* access offset */ | |
278 | if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), | |
279 | &offset)) | |
280 | return; | |
281 | /* access size */ | |
282 | if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), | |
283 | &size)) | |
284 | return; | |
285 | /* name length (unused) */ | |
286 | if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL)) | |
287 | return; | |
288 | /* object name */ | |
289 | if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), | |
290 | NULL)) | |
291 | return; | |
292 | ||
293 | /* Strip line number; without filename it's not very helpful. */ | |
294 | strreplace(token, ':', '\0'); | |
295 | ||
296 | /* Finally, print object information. */ | |
297 | pr_err(" [%lu, %lu) '%s'", offset, offset + size, token); | |
298 | } | |
299 | } | |
300 | ||
301 | static bool __must_check get_address_stack_frame_info(const void *addr, | |
302 | unsigned long *offset, | |
303 | const char **frame_descr, | |
304 | const void **frame_pc) | |
305 | { | |
306 | unsigned long aligned_addr; | |
307 | unsigned long mem_ptr; | |
308 | const u8 *shadow_bottom; | |
309 | const u8 *shadow_ptr; | |
310 | const unsigned long *frame; | |
311 | ||
312 | BUILD_BUG_ON(IS_ENABLED(CONFIG_STACK_GROWSUP)); | |
313 | ||
314 | /* | |
315 | * NOTE: We currently only support printing frame information for | |
316 | * accesses to the task's own stack. | |
317 | */ | |
318 | if (!object_is_on_stack(addr)) | |
319 | return false; | |
320 | ||
321 | aligned_addr = round_down((unsigned long)addr, sizeof(long)); | |
322 | mem_ptr = round_down(aligned_addr, KASAN_SHADOW_SCALE_SIZE); | |
323 | shadow_ptr = kasan_mem_to_shadow((void *)aligned_addr); | |
324 | shadow_bottom = kasan_mem_to_shadow(end_of_stack(current)); | |
325 | ||
326 | while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) { | |
327 | shadow_ptr--; | |
328 | mem_ptr -= KASAN_SHADOW_SCALE_SIZE; | |
329 | } | |
330 | ||
331 | while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) { | |
332 | shadow_ptr--; | |
333 | mem_ptr -= KASAN_SHADOW_SCALE_SIZE; | |
334 | } | |
335 | ||
336 | if (shadow_ptr < shadow_bottom) | |
337 | return false; | |
338 | ||
339 | frame = (const unsigned long *)(mem_ptr + KASAN_SHADOW_SCALE_SIZE); | |
340 | if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) { | |
341 | pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n", | |
342 | frame[0]); | |
343 | return false; | |
344 | } | |
345 | ||
346 | *offset = (unsigned long)addr - (unsigned long)frame; | |
347 | *frame_descr = (const char *)frame[1]; | |
348 | *frame_pc = (void *)frame[2]; | |
349 | ||
350 | return true; | |
351 | } | |
352 | ||
353 | static void print_address_stack_frame(const void *addr) | |
354 | { | |
355 | unsigned long offset; | |
356 | const char *frame_descr; | |
357 | const void *frame_pc; | |
358 | ||
359 | if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) | |
360 | return; | |
361 | ||
362 | if (!get_address_stack_frame_info(addr, &offset, &frame_descr, | |
363 | &frame_pc)) | |
364 | return; | |
365 | ||
366 | /* | |
367 | * get_address_stack_frame_info only returns true if the given addr is | |
368 | * on the current task's stack. | |
369 | */ | |
370 | pr_err("\n"); | |
371 | pr_err("addr %px is located in stack of task %s/%d at offset %lu in frame:\n", | |
372 | addr, current->comm, task_pid_nr(current), offset); | |
373 | pr_err(" %pS\n", frame_pc); | |
374 | ||
375 | if (!frame_descr) | |
376 | return; | |
377 | ||
378 | print_decoded_frame_descr(frame_descr); | |
379 | } | |
380 | ||
ae8f06b3 | 381 | static void print_address_description(void *addr, u8 tag) |
0b24becc | 382 | { |
ae8f06b3 | 383 | struct page *page = kasan_addr_to_page(addr); |
b8c73fc2 | 384 | |
db429f16 | 385 | dump_stack(); |
b1938599 | 386 | pr_err("\n"); |
db429f16 AK |
387 | |
388 | if (page && PageSlab(page)) { | |
389 | struct kmem_cache *cache = page->slab_cache; | |
0c06f1f8 | 390 | void *object = nearest_obj(cache, page, addr); |
db429f16 | 391 | |
ae8f06b3 | 392 | describe_object(cache, object, addr, tag); |
b8c73fc2 AR |
393 | } |
394 | ||
430a05f9 AK |
395 | if (kernel_or_module_addr(addr) && !init_task_stack_addr(addr)) { |
396 | pr_err("The buggy address belongs to the variable:\n"); | |
397 | pr_err(" %pS\n", addr); | |
398 | } | |
399 | ||
400 | if (page) { | |
401 | pr_err("The buggy address belongs to the page:\n"); | |
402 | dump_page(page, "kasan: bad access detected"); | |
bebf56a1 | 403 | } |
e8969219 ME |
404 | |
405 | print_address_stack_frame(addr); | |
0b24becc AR |
406 | } |
407 | ||
408 | static bool row_is_guilty(const void *row, const void *guilty) | |
409 | { | |
410 | return (row <= guilty) && (guilty < row + SHADOW_BYTES_PER_ROW); | |
411 | } | |
412 | ||
413 | static int shadow_pointer_offset(const void *row, const void *shadow) | |
414 | { | |
415 | /* The length of ">ff00ff00ff00ff00: " is | |
416 | * 3 + (BITS_PER_LONG/8)*2 chars. | |
417 | */ | |
418 | return 3 + (BITS_PER_LONG/8)*2 + (shadow - row)*2 + | |
419 | (shadow - row) / SHADOW_BYTES_PER_BLOCK + 1; | |
420 | } | |
421 | ||
422 | static void print_shadow_for_address(const void *addr) | |
423 | { | |
424 | int i; | |
425 | const void *shadow = kasan_mem_to_shadow(addr); | |
426 | const void *shadow_row; | |
427 | ||
428 | shadow_row = (void *)round_down((unsigned long)shadow, | |
429 | SHADOW_BYTES_PER_ROW) | |
430 | - SHADOW_ROWS_AROUND_ADDR * SHADOW_BYTES_PER_ROW; | |
431 | ||
432 | pr_err("Memory state around the buggy address:\n"); | |
433 | ||
434 | for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) { | |
435 | const void *kaddr = kasan_shadow_to_mem(shadow_row); | |
436 | char buffer[4 + (BITS_PER_LONG/8)*2]; | |
f2377d4e | 437 | char shadow_buf[SHADOW_BYTES_PER_ROW]; |
0b24becc AR |
438 | |
439 | snprintf(buffer, sizeof(buffer), | |
6424f6bb | 440 | (i == 0) ? ">%px: " : " %px: ", kaddr); |
f2377d4e AK |
441 | /* |
442 | * We should not pass a shadow pointer to generic | |
443 | * function, because generic functions may try to | |
444 | * access kasan mapping for the passed address. | |
445 | */ | |
f2377d4e | 446 | memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW); |
0b24becc AR |
447 | print_hex_dump(KERN_ERR, buffer, |
448 | DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1, | |
f2377d4e | 449 | shadow_buf, SHADOW_BYTES_PER_ROW, 0); |
0b24becc AR |
450 | |
451 | if (row_is_guilty(shadow_row, shadow)) | |
452 | pr_err("%*c\n", | |
453 | shadow_pointer_offset(shadow_row, shadow), | |
454 | '^'); | |
455 | ||
456 | shadow_row += SHADOW_BYTES_PER_ROW; | |
457 | } | |
458 | } | |
459 | ||
4fba3758 | 460 | static bool report_enabled(void) |
11cd3cd6 AK |
461 | { |
462 | if (current->kasan_depth) | |
463 | return false; | |
464 | if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) | |
465 | return true; | |
466 | return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); | |
467 | } | |
468 | ||
83c4e7a0 PA |
469 | #if IS_ENABLED(CONFIG_KUNIT) |
470 | static void kasan_update_kunit_status(struct kunit *cur_test) | |
471 | { | |
472 | struct kunit_resource *resource; | |
473 | struct kunit_kasan_expectation *kasan_data; | |
474 | ||
475 | resource = kunit_find_named_resource(cur_test, "kasan_data"); | |
476 | ||
477 | if (!resource) { | |
478 | kunit_set_failure(cur_test); | |
479 | return; | |
480 | } | |
481 | ||
482 | kasan_data = (struct kunit_kasan_expectation *)resource->data; | |
483 | kasan_data->report_found = true; | |
484 | kunit_put_resource(resource); | |
485 | } | |
486 | #endif /* IS_ENABLED(CONFIG_KUNIT) */ | |
487 | ||
ee3ce779 | 488 | void kasan_report_invalid_free(void *object, unsigned long ip) |
5ab6d91a AK |
489 | { |
490 | unsigned long flags; | |
ae8f06b3 | 491 | u8 tag = get_tag(object); |
5ab6d91a | 492 | |
ae8f06b3 | 493 | object = reset_tag(object); |
83c4e7a0 PA |
494 | |
495 | #if IS_ENABLED(CONFIG_KUNIT) | |
496 | if (current->kunit_test) | |
497 | kasan_update_kunit_status(current->kunit_test); | |
498 | #endif /* IS_ENABLED(CONFIG_KUNIT) */ | |
499 | ||
11cd3cd6 | 500 | start_report(&flags); |
ee3ce779 | 501 | pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip); |
ae8f06b3 | 502 | print_tags(tag, object); |
b1938599 | 503 | pr_err("\n"); |
ae8f06b3 | 504 | print_address_description(object, tag); |
b1938599 | 505 | pr_err("\n"); |
5ab6d91a | 506 | print_shadow_for_address(object); |
11cd3cd6 | 507 | end_report(&flags); |
5ab6d91a AK |
508 | } |
509 | ||
4fba3758 AK |
510 | static void __kasan_report(unsigned long addr, size_t size, bool is_write, |
511 | unsigned long ip) | |
0b24becc AR |
512 | { |
513 | struct kasan_access_info info; | |
121e8f81 AK |
514 | void *tagged_addr; |
515 | void *untagged_addr; | |
516 | unsigned long flags; | |
0b24becc | 517 | |
83c4e7a0 PA |
518 | #if IS_ENABLED(CONFIG_KUNIT) |
519 | if (current->kunit_test) | |
520 | kasan_update_kunit_status(current->kunit_test); | |
521 | #endif /* IS_ENABLED(CONFIG_KUNIT) */ | |
522 | ||
4f40c6e5 PZ |
523 | disable_trace_on_warning(); |
524 | ||
121e8f81 AK |
525 | tagged_addr = (void *)addr; |
526 | untagged_addr = reset_tag(tagged_addr); | |
527 | ||
528 | info.access_addr = tagged_addr; | |
529 | if (addr_has_shadow(untagged_addr)) | |
530 | info.first_bad_addr = find_first_bad_addr(tagged_addr, size); | |
531 | else | |
532 | info.first_bad_addr = untagged_addr; | |
0b24becc AR |
533 | info.access_size = size; |
534 | info.is_write = is_write; | |
535 | info.ip = ip; | |
e9121076 | 536 | |
121e8f81 AK |
537 | start_report(&flags); |
538 | ||
539 | print_error_description(&info); | |
540 | if (addr_has_shadow(untagged_addr)) | |
541 | print_tags(get_tag(tagged_addr), info.first_bad_addr); | |
542 | pr_err("\n"); | |
543 | ||
544 | if (addr_has_shadow(untagged_addr)) { | |
ae8f06b3 | 545 | print_address_description(untagged_addr, get_tag(tagged_addr)); |
121e8f81 AK |
546 | pr_err("\n"); |
547 | print_shadow_for_address(info.first_bad_addr); | |
548 | } else { | |
549 | dump_stack(); | |
550 | } | |
551 | ||
552 | end_report(&flags); | |
0b24becc | 553 | } |
2f004eea | 554 | |
4fba3758 AK |
555 | bool kasan_report(unsigned long addr, size_t size, bool is_write, |
556 | unsigned long ip) | |
557 | { | |
558 | unsigned long flags = user_access_save(); | |
559 | bool ret = false; | |
560 | ||
561 | if (likely(report_enabled())) { | |
562 | __kasan_report(addr, size, is_write, ip); | |
563 | ret = true; | |
564 | } | |
565 | ||
566 | user_access_restore(flags); | |
567 | ||
568 | return ret; | |
569 | } | |
570 | ||
2f004eea JH |
571 | #ifdef CONFIG_KASAN_INLINE |
572 | /* | |
573 | * With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high | |
574 | * canonical half of the address space) cause out-of-bounds shadow memory reads | |
575 | * before the actual access. For addresses in the low canonical half of the | |
576 | * address space, as well as most non-canonical addresses, that out-of-bounds | |
577 | * shadow memory access lands in the non-canonical part of the address space. | |
578 | * Help the user figure out what the original bogus pointer was. | |
579 | */ | |
580 | void kasan_non_canonical_hook(unsigned long addr) | |
581 | { | |
582 | unsigned long orig_addr; | |
583 | const char *bug_type; | |
584 | ||
585 | if (addr < KASAN_SHADOW_OFFSET) | |
586 | return; | |
587 | ||
588 | orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT; | |
589 | /* | |
590 | * For faults near the shadow address for NULL, we can be fairly certain | |
591 | * that this is a KASAN shadow memory access. | |
592 | * For faults that correspond to shadow for low canonical addresses, we | |
593 | * can still be pretty sure - that shadow region is a fairly narrow | |
594 | * chunk of the non-canonical address space. | |
595 | * But faults that look like shadow for non-canonical addresses are a | |
596 | * really large chunk of the address space. In that case, we still | |
597 | * print the decoded address, but make it clear that this is not | |
598 | * necessarily what's actually going on. | |
599 | */ | |
600 | if (orig_addr < PAGE_SIZE) | |
601 | bug_type = "null-ptr-deref"; | |
602 | else if (orig_addr < TASK_SIZE) | |
603 | bug_type = "probably user-memory-access"; | |
604 | else | |
605 | bug_type = "maybe wild-memory-access"; | |
606 | pr_alert("KASAN: %s in range [0x%016lx-0x%016lx]\n", bug_type, | |
607 | orig_addr, orig_addr + KASAN_SHADOW_MASK); | |
608 | } | |
609 | #endif |