forked from ~ljy/RK356X_SDK_RELEASE
blame | history | patch | commit | commitdiff
hc
2023-12-11 6778948f9de86c3cfaf36725a7c87dcff9ba247f 
 kernel/mm/kasan/report.c
....@@ -1,17 +1,12 @@
11 // SPDX-License-Identifier: GPL-2.0
22 /*
3
- * This file contains common generic and tag-based KASAN error reporting code.
3
+ * This file contains common KASAN error reporting code.
44  *
55  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
66  * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
77  *
88  * Some code borrowed from https://github.com/xairy/kasan-prototype by
99  *        Andrey Konovalov <andreyknvl@gmail.com>
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
- *
1510  */
1611 
1712 #include <linux/bitops.h>
....@@ -28,17 +23,16 @@
2823 #include <linux/types.h>
2924 #include <linux/kasan.h>
3025 #include <linux/module.h>
26
+#include <linux/sched/task_stack.h>
27
+#include <linux/uaccess.h>
28
+#include <trace/events/error_report.h>
3129 
3230 #include <asm/sections.h>
3331 
32
+#include <kunit/test.h>
33
+
3434 #include "kasan.h"
3535 #include "../slab.h"
36
-
37
-/* Shadow layout customization. */
38
-#define SHADOW_BYTES_PER_BLOCK 1
39
-#define SHADOW_BLOCKS_PER_ROW 16
40
-#define SHADOW_BYTES_PER_ROW (SHADOW_BLOCKS_PER_ROW * SHADOW_BYTES_PER_BLOCK)
41
-#define SHADOW_ROWS_AROUND_ADDR 2
4236 
4337 static unsigned long kasan_flags;
4438 
....@@ -68,10 +62,15 @@
6862 static void print_error_description(struct kasan_access_info *info)
6963 {
7064 	pr_err("BUG: KASAN: %s in %pS\n",
71
-		get_bug_type(info), (void *)info->ip);
72
-	pr_err("%s of size %zu at addr %px by task %s/%d\n",
73
-		info->is_write ? "Write" : "Read", info->access_size,
74
-		info->access_addr, current->comm, task_pid_nr(current));
65
+		kasan_get_bug_type(info), (void *)info->ip);
66
+	if (info->access_size)
67
+		pr_err("%s of size %zu at addr %px by task %s/%d\n",
68
+			info->is_write ? "Write" : "Read", info->access_size,
69
+			info->access_addr, current->comm, task_pid_nr(current));
70
+	else
71
+		pr_err("%s at addr %px by task %s/%d\n",
72
+			info->is_write ? "Write" : "Read",
73
+			info->access_addr, current->comm, task_pid_nr(current));
7574 }
7675 
7776 static DEFINE_SPINLOCK(report_lock);
....@@ -86,30 +85,50 @@
8685 	pr_err("==================================================================\n");
8786 }
8887 
89
-static void end_report(unsigned long *flags)
88
+static void end_report(unsigned long *flags, unsigned long addr)
9089 {
90
+	if (!kasan_async_mode_enabled())
91
+		trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
9192 	pr_err("==================================================================\n");
9293 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
9394 	spin_unlock_irqrestore(&report_lock, *flags);
94
-	if (panic_on_warn)
95
+	if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) {
96
+		/*
97
+		 * This thread may hit another WARN() in the panic path.
98
+		 * Resetting this prevents additional WARN() from panicking the
99
+		 * system on this thread.  Other threads are blocked by the
100
+		 * panic_mutex in panic().
101
+		 */
102
+		panic_on_warn = 0;
95103 		panic("panic_on_warn set ...\n");
104
+	}
105
+#ifdef CONFIG_KASAN_HW_TAGS
106
+	if (kasan_flag_panic)
107
+		panic("kasan.fault=panic set ...\n");
108
+#endif
96109 	kasan_enable_current();
110
+}
111
+
112
+static void print_stack(depot_stack_handle_t stack)
113
+{
114
+	unsigned long *entries;
115
+	unsigned int nr_entries;
116
+
117
+	nr_entries = stack_depot_fetch(stack, &entries);
118
+	stack_trace_print(entries, nr_entries, 0);
97119 }
98120 
99121 static void print_track(struct kasan_track *track, const char *prefix)
100122 {
101123 	pr_err("%s by task %u:\n", prefix, track->pid);
102124 	if (track->stack) {
103
-		struct stack_trace trace;
104
-
105
-		depot_fetch_stack(track->stack, &trace);
106
-		print_stack_trace(&trace, 0);
125
+		print_stack(track->stack);
107126 	} else {
108127 		pr_err("(stack is not available)\n");
109128 	}
110129 }
111130 
112
-static struct page *addr_to_page(const void *addr)
131
+struct page *kasan_addr_to_page(const void *addr)
113132 {
114133 	if ((addr >= (void *)PAGE_OFFSET) &&
115134 			(addr < high_memory))
....@@ -149,18 +168,45 @@
149168 		(void *)(object_addr + cache->object_size));
150169 }
151170 
152
-static void describe_object(struct kmem_cache *cache, void *object,
153
-				const void *addr)
171
+static void describe_object_stacks(struct kmem_cache *cache, void *object,
172
+					const void *addr, u8 tag)
154173 {
155
-	struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object);
174
+	struct kasan_alloc_meta *alloc_meta;
175
+	struct kasan_track *free_track;
156176 
157
-	if (cache->flags & SLAB_KASAN) {
158
-		print_track(&alloc_info->alloc_track, "Allocated");
159
-		pr_err("\n");
160
-		print_track(&alloc_info->free_track, "Freed");
177
+	alloc_meta = kasan_get_alloc_meta(cache, object);
178
+	if (alloc_meta) {
179
+		print_track(&alloc_meta->alloc_track, "Allocated");
161180 		pr_err("\n");
162181 	}
163182 
183
+	free_track = kasan_get_free_track(cache, object, tag);
184
+	if (free_track) {
185
+		print_track(free_track, "Freed");
186
+		pr_err("\n");
187
+	}
188
+
189
+#ifdef CONFIG_KASAN_GENERIC
190
+	if (!alloc_meta)
191
+		return;
192
+	if (alloc_meta->aux_stack[0]) {
193
+		pr_err("Last potentially related work creation:\n");
194
+		print_stack(alloc_meta->aux_stack[0]);
195
+		pr_err("\n");
196
+	}
197
+	if (alloc_meta->aux_stack[1]) {
198
+		pr_err("Second to last potentially related work creation:\n");
199
+		print_stack(alloc_meta->aux_stack[1]);
200
+		pr_err("\n");
201
+	}
202
+#endif
203
+}
204
+
205
+static void describe_object(struct kmem_cache *cache, void *object,
206
+				const void *addr, u8 tag)
207
+{
208
+	if (kasan_stack_collection_enabled())
209
+		describe_object_stacks(cache, object, addr, tag);
164210 	describe_object_addr(cache, object, addr);
165211 }
166212 
....@@ -180,18 +226,18 @@
180226 			sizeof(init_thread_union.stack));
181227 }
182228 
183
-static void print_address_description(void *addr)
229
+static void print_address_description(void *addr, u8 tag)
184230 {
185
-	struct page *page = addr_to_page(addr);
231
+	struct page *page = kasan_addr_to_page(addr);
186232 
187
-	dump_stack();
233
+	dump_stack_lvl(KERN_ERR);
188234 	pr_err("\n");
189235 
190236 	if (page && PageSlab(page)) {
191237 		struct kmem_cache *cache = page->slab_cache;
192238 		void *object = nearest_obj(cache, page,	addr);
193239 
194
-		describe_object(cache, object, addr);
240
+		describe_object(cache, object, addr, tag);
195241 	}
196242 
197243 	if (kernel_or_module_addr(addr) && !init_task_stack_addr(addr)) {
....@@ -203,102 +249,159 @@
203249 		pr_err("The buggy address belongs to the page:\n");
204250 		dump_page(page, "kasan: bad access detected");
205251 	}
252
+
253
+	kasan_print_address_stack_frame(addr);
206254 }
207255 
208
-static bool row_is_guilty(const void *row, const void *guilty)
256
+static bool meta_row_is_guilty(const void *row, const void *addr)
209257 {
210
-	return (row <= guilty) && (guilty < row + SHADOW_BYTES_PER_ROW);
258
+	return (row <= addr) && (addr < row + META_MEM_BYTES_PER_ROW);
211259 }
212260 
213
-static int shadow_pointer_offset(const void *row, const void *shadow)
261
+static int meta_pointer_offset(const void *row, const void *addr)
214262 {
215
-	/* The length of ">ff00ff00ff00ff00: " is
216
-	 *    3 + (BITS_PER_LONG/8)*2 chars.
263
+	/*
264
+	 * Memory state around the buggy address:
265
+	 *  ff00ff00ff00ff00: 00 00 00 05 fe fe fe fe fe fe fe fe fe fe fe fe
266
+	 *  ...
267
+	 *
268
+	 * The length of ">ff00ff00ff00ff00: " is
269
+	 *    3 + (BITS_PER_LONG / 8) * 2 chars.
270
+	 * The length of each granule metadata is 2 bytes
271
+	 *    plus 1 byte for space.
217272 	 */
218
-	return 3 + (BITS_PER_LONG/8)*2 + (shadow - row)*2 +
219
-		(shadow - row) / SHADOW_BYTES_PER_BLOCK + 1;
273
+	return 3 + (BITS_PER_LONG / 8) * 2 +
274
+		(addr - row) / KASAN_GRANULE_SIZE * 3 + 1;
220275 }
221276 
222
-static void print_shadow_for_address(const void *addr)
277
+static void print_memory_metadata(const void *addr)
223278 {
224279 	int i;
225
-	const void *shadow = kasan_mem_to_shadow(addr);
226
-	const void *shadow_row;
280
+	void *row;
227281 
228
-	shadow_row = (void *)round_down((unsigned long)shadow,
229
-					SHADOW_BYTES_PER_ROW)
230
-		- SHADOW_ROWS_AROUND_ADDR * SHADOW_BYTES_PER_ROW;
282
+	row = (void *)round_down((unsigned long)addr, META_MEM_BYTES_PER_ROW)
283
+			- META_ROWS_AROUND_ADDR * META_MEM_BYTES_PER_ROW;
231284 
232285 	pr_err("Memory state around the buggy address:\n");
233286 
234
-	for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) {
235
-		const void *kaddr = kasan_shadow_to_mem(shadow_row);
236
-		char buffer[4 + (BITS_PER_LONG/8)*2];
237
-		char shadow_buf[SHADOW_BYTES_PER_ROW];
287
+	for (i = -META_ROWS_AROUND_ADDR; i <= META_ROWS_AROUND_ADDR; i++) {
288
+		char buffer[4 + (BITS_PER_LONG / 8) * 2];
289
+		char metadata[META_BYTES_PER_ROW];
238290 
239291 		snprintf(buffer, sizeof(buffer),
240
-			(i == 0) ? ">%px: " : " %px: ", kaddr);
292
+				(i == 0) ? ">%px: " : " %px: ", row);
293
+
241294 		/*
242295 		 * We should not pass a shadow pointer to generic
243296 		 * function, because generic functions may try to
244297 		 * access kasan mapping for the passed address.
245298 		 */
246
-		memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW);
299
+		kasan_metadata_fetch_row(&metadata[0], row);
300
+
247301 		print_hex_dump(KERN_ERR, buffer,
248
-			DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1,
249
-			shadow_buf, SHADOW_BYTES_PER_ROW, 0);
302
+			DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1,
303
+			metadata, META_BYTES_PER_ROW, 0);
250304 
251
-		if (row_is_guilty(shadow_row, shadow))
252
-			pr_err("%*c\n",
253
-				shadow_pointer_offset(shadow_row, shadow),
254
-				'^');
305
+		if (meta_row_is_guilty(row, addr))
306
+			pr_err("%*c\n", meta_pointer_offset(row, addr), '^');
255307 
256
-		shadow_row += SHADOW_BYTES_PER_ROW;
308
+		row += META_MEM_BYTES_PER_ROW;
257309 	}
258310 }
259311 
260312 static bool report_enabled(void)
261313 {
314
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
262315 	if (current->kasan_depth)
263316 		return false;
317
+#endif
264318 	if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
265319 		return true;
266320 	return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
267321 }
268322 
323
+#if IS_ENABLED(CONFIG_KUNIT)
324
+static void kasan_update_kunit_status(struct kunit *cur_test)
325
+{
326
+	struct kunit_resource *resource;
327
+	struct kunit_kasan_expectation *kasan_data;
328
+
329
+	resource = kunit_find_named_resource(cur_test, "kasan_data");
330
+
331
+	if (!resource) {
332
+		kunit_set_failure(cur_test);
333
+		return;
334
+	}
335
+
336
+	kasan_data = (struct kunit_kasan_expectation *)resource->data;
337
+	WRITE_ONCE(kasan_data->report_found, true);
338
+	kunit_put_resource(resource);
339
+}
340
+#endif /* IS_ENABLED(CONFIG_KUNIT) */
341
+
269342 void kasan_report_invalid_free(void *object, unsigned long ip)
270343 {
271344 	unsigned long flags;
345
+	u8 tag = get_tag(object);
346
+
347
+	object = kasan_reset_tag(object);
348
+
349
+#if IS_ENABLED(CONFIG_KUNIT)
350
+	if (current->kunit_test)
351
+		kasan_update_kunit_status(current->kunit_test);
352
+#endif /* IS_ENABLED(CONFIG_KUNIT) */
272353 
273354 	start_report(&flags);
274355 	pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
275
-	print_tags(get_tag(object), reset_tag(object));
276
-	object = reset_tag(object);
356
+	kasan_print_tags(tag, object);
277357 	pr_err("\n");
278
-	print_address_description(object);
358
+	print_address_description(object, tag);
279359 	pr_err("\n");
280
-	print_shadow_for_address(object);
281
-	end_report(&flags);
360
+	print_memory_metadata(object);
361
+	end_report(&flags, (unsigned long)object);
282362 }
283363 
284
-void __kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip)
364
+#ifdef CONFIG_KASAN_HW_TAGS
365
+void kasan_report_async(void)
366
+{
367
+	unsigned long flags;
368
+
369
+#if IS_ENABLED(CONFIG_KUNIT)
370
+	if (current->kunit_test)
371
+		kasan_update_kunit_status(current->kunit_test);
372
+#endif /* IS_ENABLED(CONFIG_KUNIT) */
373
+
374
+	start_report(&flags);
375
+	pr_err("BUG: KASAN: invalid-access\n");
376
+	pr_err("Asynchronous mode enabled: no access details available\n");
377
+	pr_err("\n");
378
+	dump_stack_lvl(KERN_ERR);
379
+	end_report(&flags, 0);
380
+}
381
+#endif /* CONFIG_KASAN_HW_TAGS */
382
+
383
+static void __kasan_report(unsigned long addr, size_t size, bool is_write,
384
+				unsigned long ip)
285385 {
286386 	struct kasan_access_info info;
287387 	void *tagged_addr;
288388 	void *untagged_addr;
289389 	unsigned long flags;
290390 
291
-	if (likely(!report_enabled()))
292
-		return;
391
+#if IS_ENABLED(CONFIG_KUNIT)
392
+	if (current->kunit_test)
393
+		kasan_update_kunit_status(current->kunit_test);
394
+#endif /* IS_ENABLED(CONFIG_KUNIT) */
293395 
294396 	disable_trace_on_warning();
295397 
296398 	tagged_addr = (void *)addr;
297
-	untagged_addr = reset_tag(tagged_addr);
399
+	untagged_addr = kasan_reset_tag(tagged_addr);
298400 
299401 	info.access_addr = tagged_addr;
300
-	if (addr_has_shadow(untagged_addr))
301
-		info.first_bad_addr = find_first_bad_addr(tagged_addr, size);
402
+	if (addr_has_metadata(untagged_addr))
403
+		info.first_bad_addr =
404
+			kasan_find_first_bad_addr(tagged_addr, size);
302405 	else
303406 		info.first_bad_addr = untagged_addr;
304407 	info.access_size = size;
....@@ -308,17 +411,73 @@
308411 	start_report(&flags);
309412 
310413 	print_error_description(&info);
311
-	if (addr_has_shadow(untagged_addr))
312
-		print_tags(get_tag(tagged_addr), info.first_bad_addr);
414
+	if (addr_has_metadata(untagged_addr))
415
+		kasan_print_tags(get_tag(tagged_addr), info.first_bad_addr);
313416 	pr_err("\n");
314417 
315
-	if (addr_has_shadow(untagged_addr)) {
316
-		print_address_description(untagged_addr);
418
+	if (addr_has_metadata(untagged_addr)) {
419
+		print_address_description(untagged_addr, get_tag(tagged_addr));
317420 		pr_err("\n");
318
-		print_shadow_for_address(info.first_bad_addr);
421
+		print_memory_metadata(info.first_bad_addr);
319422 	} else {
320
-		dump_stack();
423
+		dump_stack_lvl(KERN_ERR);
321424 	}
322425 
323
-	end_report(&flags);
426
+	end_report(&flags, addr);
324427 }
428
+
429
+bool kasan_report(unsigned long addr, size_t size, bool is_write,
430
+			unsigned long ip)
431
+{
432
+	unsigned long flags = user_access_save();
433
+	bool ret = false;
434
+
435
+	if (likely(report_enabled())) {
436
+		__kasan_report(addr, size, is_write, ip);
437
+		ret = true;
438
+	}
439
+
440
+	user_access_restore(flags);
441
+
442
+	return ret;
443
+}
444
+
445
+#ifdef CONFIG_KASAN_INLINE
446
+/*
447
+ * With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high
448
+ * canonical half of the address space) cause out-of-bounds shadow memory reads
449
+ * before the actual access. For addresses in the low canonical half of the
450
+ * address space, as well as most non-canonical addresses, that out-of-bounds
451
+ * shadow memory access lands in the non-canonical part of the address space.
452
+ * Help the user figure out what the original bogus pointer was.
453
+ */
454
+void kasan_non_canonical_hook(unsigned long addr)
455
+{
456
+	unsigned long orig_addr;
457
+	const char *bug_type;
458
+
459
+	if (addr < KASAN_SHADOW_OFFSET)
460
+		return;
461
+
462
+	orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT;
463
+	/*
464
+	 * For faults near the shadow address for NULL, we can be fairly certain
465
+	 * that this is a KASAN shadow memory access.
466
+	 * For faults that correspond to shadow for low canonical addresses, we
467
+	 * can still be pretty sure - that shadow region is a fairly narrow
468
+	 * chunk of the non-canonical address space.
469
+	 * But faults that look like shadow for non-canonical addresses are a
470
+	 * really large chunk of the address space. In that case, we still
471
+	 * print the decoded address, but make it clear that this is not
472
+	 * necessarily what's actually going on.
473
+	 */
474
+	if (orig_addr < PAGE_SIZE)
475
+		bug_type = "null-ptr-deref";
476
+	else if (orig_addr < TASK_SIZE)
477
+		bug_type = "probably user-memory-access";
478
+	else
479
+		bug_type = "maybe wild-memory-access";
480
+	pr_alert("KASAN: %s in range [0x%016lx-0x%016lx]\n", bug_type,
481
+		 orig_addr, orig_addr + KASAN_GRANULE_SIZE - 1);
482
+}
483
+#endif