// 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>
#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
{
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);
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();
}
(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);
}
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);
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);
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)
pr_err("\n");
print_address_description(object, tag);
pr_err("\n");
- print_shadow_for_address(object);
+ print_memory_metadata(object);
end_report(&flags);
}
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;
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();
}
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
projects / linux-2.6-microblaze.git / blobdiff