forked from Minki/linux
59a2ceeef6
Merge more updates from Andrew Morton: "87 patches. Subsystems affected by this patch series: mm (pagecache and hugetlb), procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs, init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork, sysvfs, kcov, gdb, resource, selftests, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits) ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL ipc: check checkpoint_restore_ns_capable() to modify C/R proc files selftests/kselftest/runner/run_one(): allow running non-executable files virtio-mem: disallow mapping virtio-mem memory via /dev/mem kernel/resource: disallow access to exclusive system RAM regions kernel/resource: clean up and optimize iomem_is_exclusive() scripts/gdb: handle split debug for vmlinux kcov: replace local_irq_save() with a local_lock_t kcov: avoid enable+disable interrupts if !in_task() kcov: allocate per-CPU memory on the relevant node Documentation/kcov: define `ip' in the example Documentation/kcov: include types.h in the example sysv: use BUILD_BUG_ON instead of runtime check kernel/fork.c: unshare(): use swap() to make code cleaner seq_file: fix passing wrong private data seq_file: move seq_escape() to a header signal: remove duplicate include in signal.h crash_dump: remove duplicate include in crash_dump.h crash_dump: fix boolreturn.cocci warning hfs/hfsplus: use WARN_ON for sanity check ...
498 lines
13 KiB
C
498 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* 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>
|
|
*/
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/stackdepot.h>
|
|
#include <linux/stacktrace.h>
|
|
#include <linux/string.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kasan.h>
|
|
#include <linux/module.h>
|
|
#include <linux/sched/task_stack.h>
|
|
#include <linux/uaccess.h>
|
|
#include <trace/events/error_report.h>
|
|
|
|
#include <asm/sections.h>
|
|
|
|
#include <kunit/test.h>
|
|
|
|
#include "kasan.h"
|
|
#include "../slab.h"
|
|
|
|
static unsigned long kasan_flags;
|
|
|
|
#define KASAN_BIT_REPORTED 0
|
|
#define KASAN_BIT_MULTI_SHOT 1
|
|
|
|
enum kasan_arg_fault {
|
|
KASAN_ARG_FAULT_DEFAULT,
|
|
KASAN_ARG_FAULT_REPORT,
|
|
KASAN_ARG_FAULT_PANIC,
|
|
};
|
|
|
|
static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
|
|
|
|
/* kasan.fault=report/panic */
|
|
static int __init early_kasan_fault(char *arg)
|
|
{
|
|
if (!arg)
|
|
return -EINVAL;
|
|
|
|
if (!strcmp(arg, "report"))
|
|
kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
|
|
else if (!strcmp(arg, "panic"))
|
|
kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
|
|
else
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
early_param("kasan.fault", early_kasan_fault);
|
|
|
|
bool kasan_save_enable_multi_shot(void)
|
|
{
|
|
return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot);
|
|
|
|
void kasan_restore_multi_shot(bool enabled)
|
|
{
|
|
if (!enabled)
|
|
clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
|
|
|
|
static int __init kasan_set_multi_shot(char *str)
|
|
{
|
|
set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
|
|
return 1;
|
|
}
|
|
__setup("kasan_multi_shot", kasan_set_multi_shot);
|
|
|
|
static void print_error_description(struct kasan_access_info *info)
|
|
{
|
|
pr_err("BUG: KASAN: %s in %pS\n",
|
|
kasan_get_bug_type(info), (void *)info->ip);
|
|
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);
|
|
|
|
static void start_report(unsigned long *flags)
|
|
{
|
|
/*
|
|
* Make sure we don't end up in loop.
|
|
*/
|
|
kasan_disable_current();
|
|
spin_lock_irqsave(&report_lock, *flags);
|
|
pr_err("==================================================================\n");
|
|
}
|
|
|
|
static void end_report(unsigned long *flags, unsigned long addr)
|
|
{
|
|
if (!kasan_async_fault_possible())
|
|
trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
|
|
pr_err("==================================================================\n");
|
|
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
|
|
spin_unlock_irqrestore(&report_lock, *flags);
|
|
if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) {
|
|
/*
|
|
* This thread may hit another WARN() in the panic path.
|
|
* Resetting this prevents additional WARN() from panicking the
|
|
* system on this thread. Other threads are blocked by the
|
|
* panic_mutex in panic().
|
|
*/
|
|
panic_on_warn = 0;
|
|
panic("panic_on_warn set ...\n");
|
|
}
|
|
if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
|
|
panic("kasan.fault=panic set ...\n");
|
|
kasan_enable_current();
|
|
}
|
|
|
|
static void print_track(struct kasan_track *track, const char *prefix)
|
|
{
|
|
pr_err("%s by task %u:\n", prefix, track->pid);
|
|
if (track->stack) {
|
|
stack_depot_print(track->stack);
|
|
} else {
|
|
pr_err("(stack is not available)\n");
|
|
}
|
|
}
|
|
|
|
struct page *kasan_addr_to_page(const void *addr)
|
|
{
|
|
if ((addr >= (void *)PAGE_OFFSET) &&
|
|
(addr < high_memory))
|
|
return virt_to_head_page(addr);
|
|
return NULL;
|
|
}
|
|
|
|
static void describe_object_addr(struct kmem_cache *cache, void *object,
|
|
const void *addr)
|
|
{
|
|
unsigned long access_addr = (unsigned long)addr;
|
|
unsigned long object_addr = (unsigned long)object;
|
|
const char *rel_type;
|
|
int rel_bytes;
|
|
|
|
pr_err("The buggy address belongs to the object at %px\n"
|
|
" which belongs to the cache %s of size %d\n",
|
|
object, cache->name, cache->object_size);
|
|
|
|
if (!addr)
|
|
return;
|
|
|
|
if (access_addr < object_addr) {
|
|
rel_type = "to the left";
|
|
rel_bytes = object_addr - access_addr;
|
|
} else if (access_addr >= object_addr + cache->object_size) {
|
|
rel_type = "to the right";
|
|
rel_bytes = access_addr - (object_addr + cache->object_size);
|
|
} else {
|
|
rel_type = "inside";
|
|
rel_bytes = access_addr - object_addr;
|
|
}
|
|
|
|
pr_err("The buggy address is located %d bytes %s of\n"
|
|
" %d-byte region [%px, %px)\n",
|
|
rel_bytes, rel_type, cache->object_size, (void *)object_addr,
|
|
(void *)(object_addr + cache->object_size));
|
|
}
|
|
|
|
static void describe_object_stacks(struct kmem_cache *cache, void *object,
|
|
const void *addr, u8 tag)
|
|
{
|
|
struct kasan_alloc_meta *alloc_meta;
|
|
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");
|
|
}
|
|
|
|
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_meta)
|
|
return;
|
|
if (alloc_meta->aux_stack[0]) {
|
|
pr_err("Last potentially related work creation:\n");
|
|
stack_depot_print(alloc_meta->aux_stack[0]);
|
|
pr_err("\n");
|
|
}
|
|
if (alloc_meta->aux_stack[1]) {
|
|
pr_err("Second to last potentially related work creation:\n");
|
|
stack_depot_print(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);
|
|
}
|
|
|
|
static inline bool kernel_or_module_addr(const void *addr)
|
|
{
|
|
if (is_kernel((unsigned long)addr))
|
|
return true;
|
|
if (is_module_address((unsigned long)addr))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
static inline bool init_task_stack_addr(const void *addr)
|
|
{
|
|
return addr >= (void *)&init_thread_union.stack &&
|
|
(addr <= (void *)&init_thread_union.stack +
|
|
sizeof(init_thread_union.stack));
|
|
}
|
|
|
|
static void print_address_description(void *addr, u8 tag)
|
|
{
|
|
struct page *page = kasan_addr_to_page(addr);
|
|
|
|
dump_stack_lvl(KERN_ERR);
|
|
pr_err("\n");
|
|
|
|
if (page && PageSlab(page)) {
|
|
struct kmem_cache *cache = page->slab_cache;
|
|
void *object = nearest_obj(cache, page, addr);
|
|
|
|
describe_object(cache, object, addr, tag);
|
|
}
|
|
|
|
if (kernel_or_module_addr(addr) && !init_task_stack_addr(addr)) {
|
|
pr_err("The buggy address belongs to the variable:\n");
|
|
pr_err(" %pS\n", addr);
|
|
}
|
|
|
|
if (page) {
|
|
pr_err("The buggy address belongs to the page:\n");
|
|
dump_page(page, "kasan: bad access detected");
|
|
}
|
|
|
|
kasan_print_address_stack_frame(addr);
|
|
}
|
|
|
|
static bool meta_row_is_guilty(const void *row, const void *addr)
|
|
{
|
|
return (row <= addr) && (addr < row + META_MEM_BYTES_PER_ROW);
|
|
}
|
|
|
|
static int meta_pointer_offset(const void *row, const void *addr)
|
|
{
|
|
/*
|
|
* 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 +
|
|
(addr - row) / KASAN_GRANULE_SIZE * 3 + 1;
|
|
}
|
|
|
|
static void print_memory_metadata(const void *addr)
|
|
{
|
|
int i;
|
|
void *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 = -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: ", row);
|
|
|
|
/*
|
|
* We should not pass a shadow pointer to generic
|
|
* function, because generic functions may try to
|
|
* access kasan mapping for the passed address.
|
|
*/
|
|
kasan_metadata_fetch_row(&metadata[0], row);
|
|
|
|
print_hex_dump(KERN_ERR, buffer,
|
|
DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1,
|
|
metadata, META_BYTES_PER_ROW, 0);
|
|
|
|
if (meta_row_is_guilty(row, addr))
|
|
pr_err("%*c\n", meta_pointer_offset(row, addr), '^');
|
|
|
|
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);
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_KUNIT)
|
|
static void kasan_update_kunit_status(struct kunit *cur_test)
|
|
{
|
|
struct kunit_resource *resource;
|
|
struct kunit_kasan_expectation *kasan_data;
|
|
|
|
resource = kunit_find_named_resource(cur_test, "kasan_data");
|
|
|
|
if (!resource) {
|
|
kunit_set_failure(cur_test);
|
|
return;
|
|
}
|
|
|
|
kasan_data = (struct kunit_kasan_expectation *)resource->data;
|
|
WRITE_ONCE(kasan_data->report_found, true);
|
|
kunit_put_resource(resource);
|
|
}
|
|
#endif /* IS_ENABLED(CONFIG_KUNIT) */
|
|
|
|
void kasan_report_invalid_free(void *object, unsigned long ip)
|
|
{
|
|
unsigned long flags;
|
|
u8 tag = get_tag(object);
|
|
|
|
object = kasan_reset_tag(object);
|
|
|
|
#if IS_ENABLED(CONFIG_KUNIT)
|
|
if (current->kunit_test)
|
|
kasan_update_kunit_status(current->kunit_test);
|
|
#endif /* IS_ENABLED(CONFIG_KUNIT) */
|
|
|
|
start_report(&flags);
|
|
pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
|
|
kasan_print_tags(tag, object);
|
|
pr_err("\n");
|
|
print_address_description(object, tag);
|
|
pr_err("\n");
|
|
print_memory_metadata(object);
|
|
end_report(&flags, (unsigned long)object);
|
|
}
|
|
|
|
#ifdef CONFIG_KASAN_HW_TAGS
|
|
void kasan_report_async(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
#if IS_ENABLED(CONFIG_KUNIT)
|
|
if (current->kunit_test)
|
|
kasan_update_kunit_status(current->kunit_test);
|
|
#endif /* IS_ENABLED(CONFIG_KUNIT) */
|
|
|
|
start_report(&flags);
|
|
pr_err("BUG: KASAN: invalid-access\n");
|
|
pr_err("Asynchronous mode enabled: no access details available\n");
|
|
pr_err("\n");
|
|
dump_stack_lvl(KERN_ERR);
|
|
end_report(&flags, 0);
|
|
}
|
|
#endif /* CONFIG_KASAN_HW_TAGS */
|
|
|
|
static void __kasan_report(unsigned long addr, size_t size, bool is_write,
|
|
unsigned long ip)
|
|
{
|
|
struct kasan_access_info info;
|
|
void *tagged_addr;
|
|
void *untagged_addr;
|
|
unsigned long flags;
|
|
|
|
#if IS_ENABLED(CONFIG_KUNIT)
|
|
if (current->kunit_test)
|
|
kasan_update_kunit_status(current->kunit_test);
|
|
#endif /* IS_ENABLED(CONFIG_KUNIT) */
|
|
|
|
disable_trace_on_warning();
|
|
|
|
tagged_addr = (void *)addr;
|
|
untagged_addr = kasan_reset_tag(tagged_addr);
|
|
|
|
info.access_addr = tagged_addr;
|
|
if (addr_has_metadata(untagged_addr))
|
|
info.first_bad_addr =
|
|
kasan_find_first_bad_addr(tagged_addr, size);
|
|
else
|
|
info.first_bad_addr = untagged_addr;
|
|
info.access_size = size;
|
|
info.is_write = is_write;
|
|
info.ip = ip;
|
|
|
|
start_report(&flags);
|
|
|
|
print_error_description(&info);
|
|
if (addr_has_metadata(untagged_addr))
|
|
kasan_print_tags(get_tag(tagged_addr), info.first_bad_addr);
|
|
pr_err("\n");
|
|
|
|
if (addr_has_metadata(untagged_addr)) {
|
|
print_address_description(untagged_addr, get_tag(tagged_addr));
|
|
pr_err("\n");
|
|
print_memory_metadata(info.first_bad_addr);
|
|
} else {
|
|
dump_stack_lvl(KERN_ERR);
|
|
}
|
|
|
|
end_report(&flags, addr);
|
|
}
|
|
|
|
bool kasan_report(unsigned long addr, size_t size, bool is_write,
|
|
unsigned long ip)
|
|
{
|
|
unsigned long flags = user_access_save();
|
|
bool ret = false;
|
|
|
|
if (likely(report_enabled())) {
|
|
__kasan_report(addr, size, is_write, ip);
|
|
ret = true;
|
|
}
|
|
|
|
user_access_restore(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_KASAN_INLINE
|
|
/*
|
|
* With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high
|
|
* canonical half of the address space) cause out-of-bounds shadow memory reads
|
|
* before the actual access. For addresses in the low canonical half of the
|
|
* address space, as well as most non-canonical addresses, that out-of-bounds
|
|
* shadow memory access lands in the non-canonical part of the address space.
|
|
* Help the user figure out what the original bogus pointer was.
|
|
*/
|
|
void kasan_non_canonical_hook(unsigned long addr)
|
|
{
|
|
unsigned long orig_addr;
|
|
const char *bug_type;
|
|
|
|
if (addr < KASAN_SHADOW_OFFSET)
|
|
return;
|
|
|
|
orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT;
|
|
/*
|
|
* For faults near the shadow address for NULL, we can be fairly certain
|
|
* that this is a KASAN shadow memory access.
|
|
* For faults that correspond to shadow for low canonical addresses, we
|
|
* can still be pretty sure - that shadow region is a fairly narrow
|
|
* chunk of the non-canonical address space.
|
|
* But faults that look like shadow for non-canonical addresses are a
|
|
* really large chunk of the address space. In that case, we still
|
|
* print the decoded address, but make it clear that this is not
|
|
* necessarily what's actually going on.
|
|
*/
|
|
if (orig_addr < PAGE_SIZE)
|
|
bug_type = "null-ptr-deref";
|
|
else if (orig_addr < TASK_SIZE)
|
|
bug_type = "probably user-memory-access";
|
|
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_GRANULE_SIZE - 1);
|
|
}
|
|
#endif
|