1 files changed, 84 insertions, 233 deletions

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 5a0102f37171..c0fb21797550 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -1,17 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * This file contains common generic and tag-based KASAN error reporting code.
+ * This file contains common KASAN error reporting code.
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
  * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
  *
  * Some code borrowed from https://github.com/xairy/kasan-prototype by
  *        Andrey Konovalov <andreyknvl@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 
 #include <linux/bitops.h>
@@ -38,12 +33,6 @@
 #include "kasan.h"
 #include "../slab.h"
 
-/* Shadow layout customization. */
-#define SHADOW_BYTES_PER_BLOCK 1
-#define SHADOW_BLOCKS_PER_ROW 16
-#define SHADOW_BYTES_PER_ROW (SHADOW_BLOCKS_PER_ROW * SHADOW_BYTES_PER_BLOCK)
-#define SHADOW_ROWS_AROUND_ADDR 2
-
 static unsigned long kasan_flags;
 
 #define KASAN_BIT_REPORTED	0
@@ -73,9 +62,14 @@ static void print_error_description(struct kasan_access_info *info)
 {
 	pr_err("BUG: KASAN: %s in %pS\n",
 		get_bug_type(info), (void *)info->ip);
-	pr_err("%s of size %zu at addr %px by task %s/%d\n",
-		info->is_write ? "Write" : "Read", info->access_size,
-		info->access_addr, current->comm, task_pid_nr(current));
+	if (info->access_size)
+		pr_err("%s of size %zu at addr %px by task %s/%d\n",
+			info->is_write ? "Write" : "Read", info->access_size,
+			info->access_addr, current->comm, task_pid_nr(current));
+	else
+		pr_err("%s at addr %px by task %s/%d\n",
+			info->is_write ? "Write" : "Read",
+			info->access_addr, current->comm, task_pid_nr(current));
 }
 
 static DEFINE_SPINLOCK(report_lock);
@@ -105,6 +99,10 @@ static void end_report(unsigned long *flags)
 		panic_on_warn = 0;
 		panic("panic_on_warn set ...\n");
 	}
+#ifdef CONFIG_KASAN_HW_TAGS
+	if (kasan_flag_panic)
+		panic("kasan.fault=panic set ...\n");
+#endif
 	kasan_enable_current();
 }
 
@@ -167,36 +165,45 @@ static void describe_object_addr(struct kmem_cache *cache, void *object,
 		(void *)(object_addr + cache->object_size));
 }
 
-static void describe_object(struct kmem_cache *cache, void *object,
-				const void *addr, u8 tag)
+static void describe_object_stacks(struct kmem_cache *cache, void *object,
+					const void *addr, u8 tag)
 {
-	struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object);
+	struct kasan_alloc_meta *alloc_meta;
+	struct kasan_track *free_track;
 
-	if (cache->flags & SLAB_KASAN) {
-		struct kasan_track *free_track;
+	alloc_meta = kasan_get_alloc_meta(cache, object);
+	if (alloc_meta) {
+		print_track(&alloc_meta->alloc_track, "Allocated");
+		pr_err("\n");
+	}
 
-		print_track(&alloc_info->alloc_track, "Allocated");
+	free_track = kasan_get_free_track(cache, object, tag);
+	if (free_track) {
+		print_track(free_track, "Freed");
 		pr_err("\n");
-		free_track = kasan_get_free_track(cache, object, tag);
-		if (free_track) {
-			print_track(free_track, "Freed");
-			pr_err("\n");
-		}
+	}
 
 #ifdef CONFIG_KASAN_GENERIC
-		if (alloc_info->aux_stack[0]) {
-			pr_err("Last potentially related work creation:\n");
-			print_stack(alloc_info->aux_stack[0]);
-			pr_err("\n");
-		}
-		if (alloc_info->aux_stack[1]) {
-			pr_err("Second to last potentially related work creation:\n");
-			print_stack(alloc_info->aux_stack[1]);
-			pr_err("\n");
-		}
-#endif
+	if (!alloc_meta)
+		return;
+	if (alloc_meta->aux_stack[0]) {
+		pr_err("Last potentially related work creation:\n");
+		print_stack(alloc_meta->aux_stack[0]);
+		pr_err("\n");
 	}
+	if (alloc_meta->aux_stack[1]) {
+		pr_err("Second to last potentially related work creation:\n");
+		print_stack(alloc_meta->aux_stack[1]);
+		pr_err("\n");
+	}
+#endif
+}
 
+static void describe_object(struct kmem_cache *cache, void *object,
+				const void *addr, u8 tag)
+{
+	if (kasan_stack_collection_enabled())
+		describe_object_stacks(cache, object, addr, tag);
 	describe_object_addr(cache, object, addr);
 }
 
@@ -216,168 +223,6 @@ static inline bool init_task_stack_addr(const void *addr)
 			sizeof(init_thread_union.stack));
 }
 
-static bool __must_check tokenize_frame_descr(const char **frame_descr,
-					      char *token, size_t max_tok_len,
-					      unsigned long *value)
-{
-	const char *sep = strchr(*frame_descr, ' ');
-
-	if (sep == NULL)
-		sep = *frame_descr + strlen(*frame_descr);
-
-	if (token != NULL) {
-		const size_t tok_len = sep - *frame_descr;
-
-		if (tok_len + 1 > max_tok_len) {
-			pr_err("KASAN internal error: frame description too long: %s\n",
-			       *frame_descr);
-			return false;
-		}
-
-		/* Copy token (+ 1 byte for '\0'). */
-		strlcpy(token, *frame_descr, tok_len + 1);
-	}
-
-	/* Advance frame_descr past separator. */
-	*frame_descr = sep + 1;
-
-	if (value != NULL && kstrtoul(token, 10, value)) {
-		pr_err("KASAN internal error: not a valid number: %s\n", token);
-		return false;
-	}
-
-	return true;
-}
-
-static void print_decoded_frame_descr(const char *frame_descr)
-{
-	/*
-	 * We need to parse the following string:
-	 *    "n alloc_1 alloc_2 ... alloc_n"
-	 * where alloc_i looks like
-	 *    "offset size len name"
-	 * or "offset size len name:line".
-	 */
-
-	char token[64];
-	unsigned long num_objects;
-
-	if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
-				  &num_objects))
-		return;
-
-	pr_err("\n");
-	pr_err("this frame has %lu %s:\n", num_objects,
-	       num_objects == 1 ? "object" : "objects");
-
-	while (num_objects--) {
-		unsigned long offset;
-		unsigned long size;
-
-		/* access offset */
-		if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
-					  &offset))
-			return;
-		/* access size */
-		if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
-					  &size))
-			return;
-		/* name length (unused) */
-		if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL))
-			return;
-		/* object name */
-		if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
-					  NULL))
-			return;
-
-		/* Strip line number; without filename it's not very helpful. */
-		strreplace(token, ':', '\0');
-
-		/* Finally, print object information. */
-		pr_err(" [%lu, %lu) '%s'", offset, offset + size, token);
-	}
-}
-
-static bool __must_check get_address_stack_frame_info(const void *addr,
-						      unsigned long *offset,
-						      const char **frame_descr,
-						      const void **frame_pc)
-{
-	unsigned long aligned_addr;
-	unsigned long mem_ptr;
-	const u8 *shadow_bottom;
-	const u8 *shadow_ptr;
-	const unsigned long *frame;
-
-	BUILD_BUG_ON(IS_ENABLED(CONFIG_STACK_GROWSUP));
-
-	/*
-	 * NOTE: We currently only support printing frame information for
-	 * accesses to the task's own stack.
-	 */
-	if (!object_is_on_stack(addr))
-		return false;
-
-	aligned_addr = round_down((unsigned long)addr, sizeof(long));
-	mem_ptr = round_down(aligned_addr, KASAN_SHADOW_SCALE_SIZE);
-	shadow_ptr = kasan_mem_to_shadow((void *)aligned_addr);
-	shadow_bottom = kasan_mem_to_shadow(end_of_stack(current));
-
-	while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) {
-		shadow_ptr--;
-		mem_ptr -= KASAN_SHADOW_SCALE_SIZE;
-	}
-
-	while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) {
-		shadow_ptr--;
-		mem_ptr -= KASAN_SHADOW_SCALE_SIZE;
-	}
-
-	if (shadow_ptr < shadow_bottom)
-		return false;
-
-	frame = (const unsigned long *)(mem_ptr + KASAN_SHADOW_SCALE_SIZE);
-	if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) {
-		pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n",
-		       frame[0]);
-		return false;
-	}
-
-	*offset = (unsigned long)addr - (unsigned long)frame;
-	*frame_descr = (const char *)frame[1];
-	*frame_pc = (void *)frame[2];
-
-	return true;
-}
-
-static void print_address_stack_frame(const void *addr)
-{
-	unsigned long offset;
-	const char *frame_descr;
-	const void *frame_pc;
-
-	if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
-		return;
-
-	if (!get_address_stack_frame_info(addr, &offset, &frame_descr,
-					  &frame_pc))
-		return;
-
-	/*
-	 * get_address_stack_frame_info only returns true if the given addr is
-	 * on the current task's stack.
-	 */
-	pr_err("\n");
-	pr_err("addr %px is located in stack of task %s/%d at offset %lu in frame:\n",
-	       addr, current->comm, task_pid_nr(current), offset);
-	pr_err(" %pS\n", frame_pc);
-
-	if (!frame_descr)
-		return;
-
-	print_decoded_frame_descr(frame_descr);
-}
-
 static void print_address_description(void *addr, u8 tag)
 {
 	struct page *page = kasan_addr_to_page(addr);
@@ -405,62 +250,68 @@ static void print_address_description(void *addr, u8 tag)
 	print_address_stack_frame(addr);
 }
 
-static bool row_is_guilty(const void *row, const void *guilty)
+static bool meta_row_is_guilty(const void *row, const void *addr)
 {
-	return (row <= guilty) && (guilty < row + SHADOW_BYTES_PER_ROW);
+	return (row <= addr) && (addr < row + META_MEM_BYTES_PER_ROW);
 }
 
-static int shadow_pointer_offset(const void *row, const void *shadow)
+static int meta_pointer_offset(const void *row, const void *addr)
 {
-	/* The length of ">ff00ff00ff00ff00: " is
-	 *    3 + (BITS_PER_LONG/8)*2 chars.
+	/*
+	 * Memory state around the buggy address:
+	 *  ff00ff00ff00ff00: 00 00 00 05 fe fe fe fe fe fe fe fe fe fe fe fe
+	 *  ...
+	 *
+	 * The length of ">ff00ff00ff00ff00: " is
+	 *    3 + (BITS_PER_LONG / 8) * 2 chars.
+	 * The length of each granule metadata is 2 bytes
+	 *    plus 1 byte for space.
 	 */
-	return 3 + (BITS_PER_LONG/8)*2 + (shadow - row)*2 +
-		(shadow - row) / SHADOW_BYTES_PER_BLOCK + 1;
+	return 3 + (BITS_PER_LONG / 8) * 2 +
+		(addr - row) / KASAN_GRANULE_SIZE * 3 + 1;
 }
 
-static void print_shadow_for_address(const void *addr)
+static void print_memory_metadata(const void *addr)
 {
 	int i;
-	const void *shadow = kasan_mem_to_shadow(addr);
-	const void *shadow_row;
+	void *row;
 
-	shadow_row = (void *)round_down((unsigned long)shadow,
-					SHADOW_BYTES_PER_ROW)
-		- SHADOW_ROWS_AROUND_ADDR * SHADOW_BYTES_PER_ROW;
+	row = (void *)round_down((unsigned long)addr, META_MEM_BYTES_PER_ROW)
+			- META_ROWS_AROUND_ADDR * META_MEM_BYTES_PER_ROW;
 
 	pr_err("Memory state around the buggy address:\n");
 
-	for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) {
-		const void *kaddr = kasan_shadow_to_mem(shadow_row);
-		char buffer[4 + (BITS_PER_LONG/8)*2];
-		char shadow_buf[SHADOW_BYTES_PER_ROW];
+	for (i = -META_ROWS_AROUND_ADDR; i <= META_ROWS_AROUND_ADDR; i++) {
+		char buffer[4 + (BITS_PER_LONG / 8) * 2];
+		char metadata[META_BYTES_PER_ROW];
 
 		snprintf(buffer, sizeof(buffer),
-			(i == 0) ? ">%px: " : " %px: ", kaddr);
+				(i == 0) ? ">%px: " : " %px: ", row);
+
 		/*
 		 * We should not pass a shadow pointer to generic
 		 * function, because generic functions may try to
 		 * access kasan mapping for the passed address.
 		 */
-		memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW);
+		metadata_fetch_row(&metadata[0], row);
+
 		print_hex_dump(KERN_ERR, buffer,
-			DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1,
-			shadow_buf, SHADOW_BYTES_PER_ROW, 0);
+			DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1,
+			metadata, META_BYTES_PER_ROW, 0);
 
-		if (row_is_guilty(shadow_row, shadow))
-			pr_err("%*c\n",
-				shadow_pointer_offset(shadow_row, shadow),
-				'^');
+		if (meta_row_is_guilty(row, addr))
+			pr_err("%*c\n", meta_pointer_offset(row, addr), '^');
 
-		shadow_row += SHADOW_BYTES_PER_ROW;
+		row += META_MEM_BYTES_PER_ROW;
 	}
 }
 
 static bool report_enabled(void)
 {
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 	if (current->kasan_depth)
 		return false;
+#endif
 	if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
 		return true;
 	return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
@@ -490,7 +341,7 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
 	unsigned long flags;
 	u8 tag = get_tag(object);
 
-	object = reset_tag(object);
+	object = kasan_reset_tag(object);
 
 #if IS_ENABLED(CONFIG_KUNIT)
 	if (current->kunit_test)
@@ -503,7 +354,7 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
 	pr_err("\n");
 	print_address_description(object, tag);
 	pr_err("\n");
-	print_shadow_for_address(object);
+	print_memory_metadata(object);
 	end_report(&flags);
 }
 
@@ -523,10 +374,10 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write,
 	disable_trace_on_warning();
 
 	tagged_addr = (void *)addr;
-	untagged_addr = reset_tag(tagged_addr);
+	untagged_addr = kasan_reset_tag(tagged_addr);
 
 	info.access_addr = tagged_addr;
-	if (addr_has_shadow(untagged_addr))
+	if (addr_has_metadata(untagged_addr))
 		info.first_bad_addr = find_first_bad_addr(tagged_addr, size);
 	else
 		info.first_bad_addr = untagged_addr;
@@ -537,14 +388,14 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write,
 	start_report(&flags);
 
 	print_error_description(&info);
-	if (addr_has_shadow(untagged_addr))
+	if (addr_has_metadata(untagged_addr))
 		print_tags(get_tag(tagged_addr), info.first_bad_addr);
 	pr_err("\n");
 
-	if (addr_has_shadow(untagged_addr)) {
+	if (addr_has_metadata(untagged_addr)) {
 		print_address_description(untagged_addr, get_tag(tagged_addr));
 		pr_err("\n");
-		print_shadow_for_address(info.first_bad_addr);
+		print_memory_metadata(info.first_bad_addr);
 	} else {
 		dump_stack();
 	}
@@ -604,6 +455,6 @@ void kasan_non_canonical_hook(unsigned long addr)
 	else
 		bug_type = "maybe wild-memory-access";
 	pr_alert("KASAN: %s in range [0x%016lx-0x%016lx]\n", bug_type,
-		 orig_addr, orig_addr + KASAN_SHADOW_MASK);
+		 orig_addr, orig_addr + KASAN_GRANULE_SIZE - 1);
 }
 #endif