^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * This file contains common KASAN error reporting code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2014 Samsung Electronics Co., Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Some code borrowed from https://github.com/xairy/kasan-prototype by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Andrey Konovalov <andreyknvl@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/ftrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/printk.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/stackdepot.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/kasan.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/sched/task_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <trace/events/error_report.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <asm/sections.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <kunit/test.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include "kasan.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include "../slab.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static unsigned long kasan_flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #define KASAN_BIT_REPORTED 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #define KASAN_BIT_MULTI_SHOT 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) bool kasan_save_enable_multi_shot(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) void kasan_restore_multi_shot(bool enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if (!enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) static int __init kasan_set_multi_shot(char *str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) __setup("kasan_multi_shot", kasan_set_multi_shot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) static void print_error_description(struct kasan_access_info *info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) pr_err("BUG: KASAN: %s in %pS\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) kasan_get_bug_type(info), (void *)info->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) if (info->access_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) pr_err("%s of size %zu at addr %px by task %s/%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) info->is_write ? "Write" : "Read", info->access_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) info->access_addr, current->comm, task_pid_nr(current));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) pr_err("%s at addr %px by task %s/%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) info->is_write ? "Write" : "Read",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) info->access_addr, current->comm, task_pid_nr(current));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) static DEFINE_SPINLOCK(report_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) static void start_report(unsigned long *flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * Make sure we don't end up in loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) kasan_disable_current();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) spin_lock_irqsave(&report_lock, *flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) pr_err("==================================================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) static void end_report(unsigned long *flags, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (!kasan_async_mode_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) pr_err("==================================================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) spin_unlock_irqrestore(&report_lock, *flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * This thread may hit another WARN() in the panic path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * Resetting this prevents additional WARN() from panicking the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * system on this thread. Other threads are blocked by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * panic_mutex in panic().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) panic_on_warn = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) panic("panic_on_warn set ...\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) #ifdef CONFIG_KASAN_HW_TAGS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) if (kasan_flag_panic)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) panic("kasan.fault=panic set ...\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) kasan_enable_current();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) static void print_stack(depot_stack_handle_t stack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) unsigned long *entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) unsigned int nr_entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) nr_entries = stack_depot_fetch(stack, &entries);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) stack_trace_print(entries, nr_entries, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) static void print_track(struct kasan_track *track, const char *prefix)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) pr_err("%s by task %u:\n", prefix, track->pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) if (track->stack) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) print_stack(track->stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) pr_err("(stack is not available)\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) struct page *kasan_addr_to_page(const void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if ((addr >= (void *)PAGE_OFFSET) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) (addr < high_memory))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) return virt_to_head_page(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) static void describe_object_addr(struct kmem_cache *cache, void *object,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) const void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) unsigned long access_addr = (unsigned long)addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) unsigned long object_addr = (unsigned long)object;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) const char *rel_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) int rel_bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) pr_err("The buggy address belongs to the object at %px\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) " which belongs to the cache %s of size %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) object, cache->name, cache->object_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) if (!addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if (access_addr < object_addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) rel_type = "to the left";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) rel_bytes = object_addr - access_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) } else if (access_addr >= object_addr + cache->object_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) rel_type = "to the right";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) rel_bytes = access_addr - (object_addr + cache->object_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) rel_type = "inside";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) rel_bytes = access_addr - object_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) pr_err("The buggy address is located %d bytes %s of\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) " %d-byte region [%px, %px)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) rel_bytes, rel_type, cache->object_size, (void *)object_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) (void *)(object_addr + cache->object_size));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) static void describe_object_stacks(struct kmem_cache *cache, void *object,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) const void *addr, u8 tag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) struct kasan_alloc_meta *alloc_meta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) struct kasan_track *free_track;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) alloc_meta = kasan_get_alloc_meta(cache, object);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) if (alloc_meta) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) print_track(&alloc_meta->alloc_track, "Allocated");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) free_track = kasan_get_free_track(cache, object, tag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) if (free_track) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) print_track(free_track, "Freed");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) #ifdef CONFIG_KASAN_GENERIC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) if (!alloc_meta)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) if (alloc_meta->aux_stack[0]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) pr_err("Last potentially related work creation:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) print_stack(alloc_meta->aux_stack[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) if (alloc_meta->aux_stack[1]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) pr_err("Second to last potentially related work creation:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) print_stack(alloc_meta->aux_stack[1]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) static void describe_object(struct kmem_cache *cache, void *object,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) const void *addr, u8 tag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) if (kasan_stack_collection_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) describe_object_stacks(cache, object, addr, tag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) describe_object_addr(cache, object, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) static inline bool kernel_or_module_addr(const void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) if (addr >= (void *)_stext && addr < (void *)_end)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) if (is_module_address((unsigned long)addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) static inline bool init_task_stack_addr(const void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) return addr >= (void *)&init_thread_union.stack &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) (addr <= (void *)&init_thread_union.stack +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) sizeof(init_thread_union.stack));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) static void print_address_description(void *addr, u8 tag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) struct page *page = kasan_addr_to_page(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) dump_stack_lvl(KERN_ERR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) if (page && PageSlab(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) struct kmem_cache *cache = page->slab_cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) void *object = nearest_obj(cache, page, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) describe_object(cache, object, addr, tag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) if (kernel_or_module_addr(addr) && !init_task_stack_addr(addr)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) pr_err("The buggy address belongs to the variable:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) pr_err(" %pS\n", addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) if (page) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) pr_err("The buggy address belongs to the page:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) dump_page(page, "kasan: bad access detected");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) kasan_print_address_stack_frame(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) static bool meta_row_is_guilty(const void *row, const void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) return (row <= addr) && (addr < row + META_MEM_BYTES_PER_ROW);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) static int meta_pointer_offset(const void *row, const void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) * Memory state around the buggy address:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * ff00ff00ff00ff00: 00 00 00 05 fe fe fe fe fe fe fe fe fe fe fe fe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) * ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) * The length of ">ff00ff00ff00ff00: " is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) * 3 + (BITS_PER_LONG / 8) * 2 chars.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) * The length of each granule metadata is 2 bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) * plus 1 byte for space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) return 3 + (BITS_PER_LONG / 8) * 2 +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) (addr - row) / KASAN_GRANULE_SIZE * 3 + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) static void print_memory_metadata(const void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) void *row;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) row = (void *)round_down((unsigned long)addr, META_MEM_BYTES_PER_ROW)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) - META_ROWS_AROUND_ADDR * META_MEM_BYTES_PER_ROW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) pr_err("Memory state around the buggy address:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) for (i = -META_ROWS_AROUND_ADDR; i <= META_ROWS_AROUND_ADDR; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) char buffer[4 + (BITS_PER_LONG / 8) * 2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) char metadata[META_BYTES_PER_ROW];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) snprintf(buffer, sizeof(buffer),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) (i == 0) ? ">%px: " : " %px: ", row);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) * We should not pass a shadow pointer to generic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) * function, because generic functions may try to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) * access kasan mapping for the passed address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) kasan_metadata_fetch_row(&metadata[0], row);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) print_hex_dump(KERN_ERR, buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) metadata, META_BYTES_PER_ROW, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) if (meta_row_is_guilty(row, addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) pr_err("%*c\n", meta_pointer_offset(row, addr), '^');
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) row += META_MEM_BYTES_PER_ROW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) static bool report_enabled(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) if (current->kasan_depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) #if IS_ENABLED(CONFIG_KUNIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) static void kasan_update_kunit_status(struct kunit *cur_test)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) struct kunit_resource *resource;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) struct kunit_kasan_expectation *kasan_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) resource = kunit_find_named_resource(cur_test, "kasan_data");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (!resource) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) kunit_set_failure(cur_test);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) kasan_data = (struct kunit_kasan_expectation *)resource->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) WRITE_ONCE(kasan_data->report_found, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) kunit_put_resource(resource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) #endif /* IS_ENABLED(CONFIG_KUNIT) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) void kasan_report_invalid_free(void *object, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) u8 tag = get_tag(object);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) object = kasan_reset_tag(object);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) #if IS_ENABLED(CONFIG_KUNIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) if (current->kunit_test)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) kasan_update_kunit_status(current->kunit_test);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) #endif /* IS_ENABLED(CONFIG_KUNIT) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) start_report(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) kasan_print_tags(tag, object);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) print_address_description(object, tag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) print_memory_metadata(object);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) end_report(&flags, (unsigned long)object);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) #ifdef CONFIG_KASAN_HW_TAGS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) void kasan_report_async(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) #if IS_ENABLED(CONFIG_KUNIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) if (current->kunit_test)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) kasan_update_kunit_status(current->kunit_test);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) #endif /* IS_ENABLED(CONFIG_KUNIT) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) start_report(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) pr_err("BUG: KASAN: invalid-access\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) pr_err("Asynchronous mode enabled: no access details available\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) dump_stack_lvl(KERN_ERR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) end_report(&flags, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) #endif /* CONFIG_KASAN_HW_TAGS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) static void __kasan_report(unsigned long addr, size_t size, bool is_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) struct kasan_access_info info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) void *tagged_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) void *untagged_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) #if IS_ENABLED(CONFIG_KUNIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) if (current->kunit_test)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) kasan_update_kunit_status(current->kunit_test);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) #endif /* IS_ENABLED(CONFIG_KUNIT) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) disable_trace_on_warning();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) tagged_addr = (void *)addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) untagged_addr = kasan_reset_tag(tagged_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) info.access_addr = tagged_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) if (addr_has_metadata(untagged_addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) info.first_bad_addr =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) kasan_find_first_bad_addr(tagged_addr, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) info.first_bad_addr = untagged_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) info.access_size = size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) info.is_write = is_write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) info.ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) start_report(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) print_error_description(&info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) if (addr_has_metadata(untagged_addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) kasan_print_tags(get_tag(tagged_addr), info.first_bad_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) if (addr_has_metadata(untagged_addr)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) print_address_description(untagged_addr, get_tag(tagged_addr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) pr_err("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) print_memory_metadata(info.first_bad_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) dump_stack_lvl(KERN_ERR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) end_report(&flags, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) bool kasan_report(unsigned long addr, size_t size, bool is_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) unsigned long flags = user_access_save();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) bool ret = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) if (likely(report_enabled())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) __kasan_report(addr, size, is_write, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) ret = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) user_access_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) #ifdef CONFIG_KASAN_INLINE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) * With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * canonical half of the address space) cause out-of-bounds shadow memory reads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) * before the actual access. For addresses in the low canonical half of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) * address space, as well as most non-canonical addresses, that out-of-bounds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) * shadow memory access lands in the non-canonical part of the address space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) * Help the user figure out what the original bogus pointer was.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) void kasan_non_canonical_hook(unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) unsigned long orig_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) const char *bug_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) if (addr < KASAN_SHADOW_OFFSET)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) * For faults near the shadow address for NULL, we can be fairly certain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) * that this is a KASAN shadow memory access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) * For faults that correspond to shadow for low canonical addresses, we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) * can still be pretty sure - that shadow region is a fairly narrow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) * chunk of the non-canonical address space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) * But faults that look like shadow for non-canonical addresses are a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) * really large chunk of the address space. In that case, we still
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) * print the decoded address, but make it clear that this is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) * necessarily what's actually going on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) if (orig_addr < PAGE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) bug_type = "null-ptr-deref";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) else if (orig_addr < TASK_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) bug_type = "probably user-memory-access";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) bug_type = "maybe wild-memory-access";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) pr_alert("KASAN: %s in range [0x%016lx-0x%016lx]\n", bug_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) orig_addr, orig_addr + KASAN_GRANULE_SIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) #endif
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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