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![Zhen Lei](/assets/img/avatar_default.png)
There is a special case that the size is "(N << KASAN_SHADOW_SCALE_SHIFT) Pages plus X", the value of X is [1, KASAN_SHADOW_SCALE_SIZE-1]. The operation "size >> KASAN_SHADOW_SCALE_SHIFT" will drop X, and the roundup operation can not retrieve the missed one page. For example: size=0x28006, PAGE_SIZE=0x1000, KASAN_SHADOW_SCALE_SHIFT=3, we will get shadow_size=0x5000, but actually we need 6 pages. shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT, PAGE_SIZE); This can lead to a kernel crash when kasan is enabled and the value of mod->core_layout.size or mod->init_layout.size is like above. Because the shadow memory of X has not been allocated and mapped. move_module: ptr = module_alloc(mod->core_layout.size); ... memset(ptr, 0, mod->core_layout.size); //crashed Unable to handle kernel paging request at virtual address ffff0fffff97b000 ...... Call trace: __asan_storeN+0x174/0x1a8 memset+0x24/0x48 layout_and_allocate+0xcd8/0x1800 load_module+0x190/0x23e8 SyS_finit_module+0x148/0x180 Link: http://lkml.kernel.org/r/1529659626-12660-1-git-send-email-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Dmitriy Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Libin <huawei.libin@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
903 lines
23 KiB
C
903 lines
23 KiB
C
/*
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* This file contains shadow memory manipulation code.
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*
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* Copyright (c) 2014 Samsung Electronics Co., Ltd.
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* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
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*
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* Some code borrowed from https://github.com/xairy/kasan-prototype by
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* Andrey Konovalov <andreyknvl@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#define DISABLE_BRANCH_PROFILING
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#include <linux/export.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <linux/kasan.h>
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#include <linux/kernel.h>
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#include <linux/kmemleak.h>
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#include <linux/linkage.h>
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#include <linux/memblock.h>
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#include <linux/memory.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/printk.h>
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <linux/slab.h>
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#include <linux/stacktrace.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/vmalloc.h>
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#include <linux/bug.h>
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#include "kasan.h"
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#include "../slab.h"
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void kasan_enable_current(void)
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{
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current->kasan_depth++;
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}
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void kasan_disable_current(void)
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{
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current->kasan_depth--;
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}
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/*
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* Poisons the shadow memory for 'size' bytes starting from 'addr'.
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* Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE.
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*/
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static void kasan_poison_shadow(const void *address, size_t size, u8 value)
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{
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void *shadow_start, *shadow_end;
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shadow_start = kasan_mem_to_shadow(address);
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shadow_end = kasan_mem_to_shadow(address + size);
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memset(shadow_start, value, shadow_end - shadow_start);
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}
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void kasan_unpoison_shadow(const void *address, size_t size)
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{
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kasan_poison_shadow(address, size, 0);
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if (size & KASAN_SHADOW_MASK) {
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u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
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*shadow = size & KASAN_SHADOW_MASK;
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}
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}
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static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
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{
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void *base = task_stack_page(task);
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size_t size = sp - base;
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kasan_unpoison_shadow(base, size);
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}
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/* Unpoison the entire stack for a task. */
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void kasan_unpoison_task_stack(struct task_struct *task)
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{
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__kasan_unpoison_stack(task, task_stack_page(task) + THREAD_SIZE);
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}
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/* Unpoison the stack for the current task beyond a watermark sp value. */
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asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
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{
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/*
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* Calculate the task stack base address. Avoid using 'current'
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* because this function is called by early resume code which hasn't
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* yet set up the percpu register (%gs).
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*/
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void *base = (void *)((unsigned long)watermark & ~(THREAD_SIZE - 1));
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kasan_unpoison_shadow(base, watermark - base);
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}
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/*
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* Clear all poison for the region between the current SP and a provided
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* watermark value, as is sometimes required prior to hand-crafted asm function
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* returns in the middle of functions.
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*/
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void kasan_unpoison_stack_above_sp_to(const void *watermark)
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{
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const void *sp = __builtin_frame_address(0);
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size_t size = watermark - sp;
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if (WARN_ON(sp > watermark))
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return;
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kasan_unpoison_shadow(sp, size);
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}
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/*
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* All functions below always inlined so compiler could
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* perform better optimizations in each of __asan_loadX/__assn_storeX
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* depending on memory access size X.
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*/
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static __always_inline bool memory_is_poisoned_1(unsigned long addr)
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{
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s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr);
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if (unlikely(shadow_value)) {
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s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
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return unlikely(last_accessible_byte >= shadow_value);
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}
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return false;
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}
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static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr,
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unsigned long size)
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{
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u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr);
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/*
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* Access crosses 8(shadow size)-byte boundary. Such access maps
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* into 2 shadow bytes, so we need to check them both.
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*/
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if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1))
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return *shadow_addr || memory_is_poisoned_1(addr + size - 1);
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return memory_is_poisoned_1(addr + size - 1);
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}
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static __always_inline bool memory_is_poisoned_16(unsigned long addr)
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{
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u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
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/* Unaligned 16-bytes access maps into 3 shadow bytes. */
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if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
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return *shadow_addr || memory_is_poisoned_1(addr + 15);
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return *shadow_addr;
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}
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static __always_inline unsigned long bytes_is_nonzero(const u8 *start,
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size_t size)
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{
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while (size) {
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if (unlikely(*start))
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return (unsigned long)start;
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start++;
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size--;
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}
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return 0;
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}
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static __always_inline unsigned long memory_is_nonzero(const void *start,
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const void *end)
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{
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unsigned int words;
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unsigned long ret;
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unsigned int prefix = (unsigned long)start % 8;
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if (end - start <= 16)
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return bytes_is_nonzero(start, end - start);
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if (prefix) {
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prefix = 8 - prefix;
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ret = bytes_is_nonzero(start, prefix);
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if (unlikely(ret))
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return ret;
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start += prefix;
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}
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words = (end - start) / 8;
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while (words) {
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if (unlikely(*(u64 *)start))
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return bytes_is_nonzero(start, 8);
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start += 8;
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words--;
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}
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return bytes_is_nonzero(start, (end - start) % 8);
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}
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static __always_inline bool memory_is_poisoned_n(unsigned long addr,
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size_t size)
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{
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unsigned long ret;
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ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr),
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kasan_mem_to_shadow((void *)addr + size - 1) + 1);
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if (unlikely(ret)) {
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unsigned long last_byte = addr + size - 1;
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s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte);
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if (unlikely(ret != (unsigned long)last_shadow ||
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((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
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return true;
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}
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return false;
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}
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static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
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{
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if (__builtin_constant_p(size)) {
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switch (size) {
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case 1:
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return memory_is_poisoned_1(addr);
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case 2:
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case 4:
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case 8:
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return memory_is_poisoned_2_4_8(addr, size);
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case 16:
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return memory_is_poisoned_16(addr);
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default:
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BUILD_BUG();
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}
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}
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return memory_is_poisoned_n(addr, size);
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}
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static __always_inline void check_memory_region_inline(unsigned long addr,
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size_t size, bool write,
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unsigned long ret_ip)
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{
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if (unlikely(size == 0))
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return;
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if (unlikely((void *)addr <
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kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
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kasan_report(addr, size, write, ret_ip);
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return;
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}
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if (likely(!memory_is_poisoned(addr, size)))
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return;
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kasan_report(addr, size, write, ret_ip);
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}
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static void check_memory_region(unsigned long addr,
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size_t size, bool write,
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unsigned long ret_ip)
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{
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check_memory_region_inline(addr, size, write, ret_ip);
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}
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void kasan_check_read(const volatile void *p, unsigned int size)
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{
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check_memory_region((unsigned long)p, size, false, _RET_IP_);
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}
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EXPORT_SYMBOL(kasan_check_read);
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void kasan_check_write(const volatile void *p, unsigned int size)
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{
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check_memory_region((unsigned long)p, size, true, _RET_IP_);
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}
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EXPORT_SYMBOL(kasan_check_write);
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#undef memset
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void *memset(void *addr, int c, size_t len)
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{
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check_memory_region((unsigned long)addr, len, true, _RET_IP_);
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return __memset(addr, c, len);
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}
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#undef memmove
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void *memmove(void *dest, const void *src, size_t len)
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{
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check_memory_region((unsigned long)src, len, false, _RET_IP_);
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check_memory_region((unsigned long)dest, len, true, _RET_IP_);
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return __memmove(dest, src, len);
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}
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#undef memcpy
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void *memcpy(void *dest, const void *src, size_t len)
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{
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check_memory_region((unsigned long)src, len, false, _RET_IP_);
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check_memory_region((unsigned long)dest, len, true, _RET_IP_);
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return __memcpy(dest, src, len);
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}
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void kasan_alloc_pages(struct page *page, unsigned int order)
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{
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if (likely(!PageHighMem(page)))
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kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
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}
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void kasan_free_pages(struct page *page, unsigned int order)
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{
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if (likely(!PageHighMem(page)))
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kasan_poison_shadow(page_address(page),
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PAGE_SIZE << order,
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KASAN_FREE_PAGE);
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}
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/*
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* Adaptive redzone policy taken from the userspace AddressSanitizer runtime.
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* For larger allocations larger redzones are used.
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*/
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static unsigned int optimal_redzone(unsigned int object_size)
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{
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return
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object_size <= 64 - 16 ? 16 :
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object_size <= 128 - 32 ? 32 :
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object_size <= 512 - 64 ? 64 :
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object_size <= 4096 - 128 ? 128 :
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object_size <= (1 << 14) - 256 ? 256 :
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object_size <= (1 << 15) - 512 ? 512 :
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object_size <= (1 << 16) - 1024 ? 1024 : 2048;
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}
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void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
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slab_flags_t *flags)
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{
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unsigned int orig_size = *size;
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int redzone_adjust;
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/* Add alloc meta. */
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cache->kasan_info.alloc_meta_offset = *size;
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*size += sizeof(struct kasan_alloc_meta);
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/* Add free meta. */
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if (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor ||
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cache->object_size < sizeof(struct kasan_free_meta)) {
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cache->kasan_info.free_meta_offset = *size;
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*size += sizeof(struct kasan_free_meta);
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}
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redzone_adjust = optimal_redzone(cache->object_size) -
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(*size - cache->object_size);
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if (redzone_adjust > 0)
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*size += redzone_adjust;
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*size = min_t(unsigned int, KMALLOC_MAX_SIZE,
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max(*size, cache->object_size +
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optimal_redzone(cache->object_size)));
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/*
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* If the metadata doesn't fit, don't enable KASAN at all.
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*/
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if (*size <= cache->kasan_info.alloc_meta_offset ||
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*size <= cache->kasan_info.free_meta_offset) {
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cache->kasan_info.alloc_meta_offset = 0;
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cache->kasan_info.free_meta_offset = 0;
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*size = orig_size;
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return;
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}
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*flags |= SLAB_KASAN;
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}
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void kasan_cache_shrink(struct kmem_cache *cache)
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{
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quarantine_remove_cache(cache);
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}
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void kasan_cache_shutdown(struct kmem_cache *cache)
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{
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if (!__kmem_cache_empty(cache))
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quarantine_remove_cache(cache);
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}
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size_t kasan_metadata_size(struct kmem_cache *cache)
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{
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return (cache->kasan_info.alloc_meta_offset ?
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sizeof(struct kasan_alloc_meta) : 0) +
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(cache->kasan_info.free_meta_offset ?
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sizeof(struct kasan_free_meta) : 0);
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}
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void kasan_poison_slab(struct page *page)
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{
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kasan_poison_shadow(page_address(page),
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PAGE_SIZE << compound_order(page),
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KASAN_KMALLOC_REDZONE);
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}
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void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
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{
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kasan_unpoison_shadow(object, cache->object_size);
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}
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void kasan_poison_object_data(struct kmem_cache *cache, void *object)
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{
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kasan_poison_shadow(object,
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round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
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KASAN_KMALLOC_REDZONE);
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}
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static inline int in_irqentry_text(unsigned long ptr)
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{
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return (ptr >= (unsigned long)&__irqentry_text_start &&
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ptr < (unsigned long)&__irqentry_text_end) ||
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(ptr >= (unsigned long)&__softirqentry_text_start &&
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ptr < (unsigned long)&__softirqentry_text_end);
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}
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static inline void filter_irq_stacks(struct stack_trace *trace)
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{
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int i;
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if (!trace->nr_entries)
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return;
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for (i = 0; i < trace->nr_entries; i++)
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if (in_irqentry_text(trace->entries[i])) {
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/* Include the irqentry function into the stack. */
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trace->nr_entries = i + 1;
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break;
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}
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}
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static inline depot_stack_handle_t save_stack(gfp_t flags)
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{
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unsigned long entries[KASAN_STACK_DEPTH];
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struct stack_trace trace = {
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.nr_entries = 0,
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.entries = entries,
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.max_entries = KASAN_STACK_DEPTH,
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.skip = 0
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};
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save_stack_trace(&trace);
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filter_irq_stacks(&trace);
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if (trace.nr_entries != 0 &&
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trace.entries[trace.nr_entries-1] == ULONG_MAX)
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trace.nr_entries--;
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return depot_save_stack(&trace, flags);
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}
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static inline void set_track(struct kasan_track *track, gfp_t flags)
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{
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track->pid = current->pid;
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track->stack = save_stack(flags);
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}
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struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
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const void *object)
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{
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BUILD_BUG_ON(sizeof(struct kasan_alloc_meta) > 32);
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return (void *)object + cache->kasan_info.alloc_meta_offset;
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}
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struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
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const void *object)
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{
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BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
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return (void *)object + cache->kasan_info.free_meta_offset;
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}
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void kasan_init_slab_obj(struct kmem_cache *cache, const void *object)
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{
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struct kasan_alloc_meta *alloc_info;
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if (!(cache->flags & SLAB_KASAN))
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return;
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alloc_info = get_alloc_info(cache, object);
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__memset(alloc_info, 0, sizeof(*alloc_info));
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}
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void kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags)
|
|
{
|
|
kasan_kmalloc(cache, object, cache->object_size, flags);
|
|
}
|
|
|
|
static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
|
|
unsigned long ip, bool quarantine)
|
|
{
|
|
s8 shadow_byte;
|
|
unsigned long rounded_up_size;
|
|
|
|
if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
|
|
object)) {
|
|
kasan_report_invalid_free(object, ip);
|
|
return true;
|
|
}
|
|
|
|
/* RCU slabs could be legally used after free within the RCU period */
|
|
if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
|
|
return false;
|
|
|
|
shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object));
|
|
if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) {
|
|
kasan_report_invalid_free(object, ip);
|
|
return true;
|
|
}
|
|
|
|
rounded_up_size = round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE);
|
|
kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
|
|
|
|
if (!quarantine || unlikely(!(cache->flags & SLAB_KASAN)))
|
|
return false;
|
|
|
|
set_track(&get_alloc_info(cache, object)->free_track, GFP_NOWAIT);
|
|
quarantine_put(get_free_info(cache, object), cache);
|
|
return true;
|
|
}
|
|
|
|
bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
|
|
{
|
|
return __kasan_slab_free(cache, object, ip, true);
|
|
}
|
|
|
|
void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size,
|
|
gfp_t flags)
|
|
{
|
|
unsigned long redzone_start;
|
|
unsigned long redzone_end;
|
|
|
|
if (gfpflags_allow_blocking(flags))
|
|
quarantine_reduce();
|
|
|
|
if (unlikely(object == NULL))
|
|
return;
|
|
|
|
redzone_start = round_up((unsigned long)(object + size),
|
|
KASAN_SHADOW_SCALE_SIZE);
|
|
redzone_end = round_up((unsigned long)object + cache->object_size,
|
|
KASAN_SHADOW_SCALE_SIZE);
|
|
|
|
kasan_unpoison_shadow(object, size);
|
|
kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
|
|
KASAN_KMALLOC_REDZONE);
|
|
|
|
if (cache->flags & SLAB_KASAN)
|
|
set_track(&get_alloc_info(cache, object)->alloc_track, flags);
|
|
}
|
|
EXPORT_SYMBOL(kasan_kmalloc);
|
|
|
|
void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
|
|
{
|
|
struct page *page;
|
|
unsigned long redzone_start;
|
|
unsigned long redzone_end;
|
|
|
|
if (gfpflags_allow_blocking(flags))
|
|
quarantine_reduce();
|
|
|
|
if (unlikely(ptr == NULL))
|
|
return;
|
|
|
|
page = virt_to_page(ptr);
|
|
redzone_start = round_up((unsigned long)(ptr + size),
|
|
KASAN_SHADOW_SCALE_SIZE);
|
|
redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page));
|
|
|
|
kasan_unpoison_shadow(ptr, size);
|
|
kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
|
|
KASAN_PAGE_REDZONE);
|
|
}
|
|
|
|
void kasan_krealloc(const void *object, size_t size, gfp_t flags)
|
|
{
|
|
struct page *page;
|
|
|
|
if (unlikely(object == ZERO_SIZE_PTR))
|
|
return;
|
|
|
|
page = virt_to_head_page(object);
|
|
|
|
if (unlikely(!PageSlab(page)))
|
|
kasan_kmalloc_large(object, size, flags);
|
|
else
|
|
kasan_kmalloc(page->slab_cache, object, size, flags);
|
|
}
|
|
|
|
void kasan_poison_kfree(void *ptr, unsigned long ip)
|
|
{
|
|
struct page *page;
|
|
|
|
page = virt_to_head_page(ptr);
|
|
|
|
if (unlikely(!PageSlab(page))) {
|
|
if (ptr != page_address(page)) {
|
|
kasan_report_invalid_free(ptr, ip);
|
|
return;
|
|
}
|
|
kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
|
|
KASAN_FREE_PAGE);
|
|
} else {
|
|
__kasan_slab_free(page->slab_cache, ptr, ip, false);
|
|
}
|
|
}
|
|
|
|
void kasan_kfree_large(void *ptr, unsigned long ip)
|
|
{
|
|
if (ptr != page_address(virt_to_head_page(ptr)))
|
|
kasan_report_invalid_free(ptr, ip);
|
|
/* The object will be poisoned by page_alloc. */
|
|
}
|
|
|
|
int kasan_module_alloc(void *addr, size_t size)
|
|
{
|
|
void *ret;
|
|
size_t scaled_size;
|
|
size_t shadow_size;
|
|
unsigned long shadow_start;
|
|
|
|
shadow_start = (unsigned long)kasan_mem_to_shadow(addr);
|
|
scaled_size = (size + KASAN_SHADOW_MASK) >> KASAN_SHADOW_SCALE_SHIFT;
|
|
shadow_size = round_up(scaled_size, PAGE_SIZE);
|
|
|
|
if (WARN_ON(!PAGE_ALIGNED(shadow_start)))
|
|
return -EINVAL;
|
|
|
|
ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
|
|
shadow_start + shadow_size,
|
|
GFP_KERNEL | __GFP_ZERO,
|
|
PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
|
|
__builtin_return_address(0));
|
|
|
|
if (ret) {
|
|
find_vm_area(addr)->flags |= VM_KASAN;
|
|
kmemleak_ignore(ret);
|
|
return 0;
|
|
}
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
void kasan_free_shadow(const struct vm_struct *vm)
|
|
{
|
|
if (vm->flags & VM_KASAN)
|
|
vfree(kasan_mem_to_shadow(vm->addr));
|
|
}
|
|
|
|
static void register_global(struct kasan_global *global)
|
|
{
|
|
size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);
|
|
|
|
kasan_unpoison_shadow(global->beg, global->size);
|
|
|
|
kasan_poison_shadow(global->beg + aligned_size,
|
|
global->size_with_redzone - aligned_size,
|
|
KASAN_GLOBAL_REDZONE);
|
|
}
|
|
|
|
void __asan_register_globals(struct kasan_global *globals, size_t size)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < size; i++)
|
|
register_global(&globals[i]);
|
|
}
|
|
EXPORT_SYMBOL(__asan_register_globals);
|
|
|
|
void __asan_unregister_globals(struct kasan_global *globals, size_t size)
|
|
{
|
|
}
|
|
EXPORT_SYMBOL(__asan_unregister_globals);
|
|
|
|
#define DEFINE_ASAN_LOAD_STORE(size) \
|
|
void __asan_load##size(unsigned long addr) \
|
|
{ \
|
|
check_memory_region_inline(addr, size, false, _RET_IP_);\
|
|
} \
|
|
EXPORT_SYMBOL(__asan_load##size); \
|
|
__alias(__asan_load##size) \
|
|
void __asan_load##size##_noabort(unsigned long); \
|
|
EXPORT_SYMBOL(__asan_load##size##_noabort); \
|
|
void __asan_store##size(unsigned long addr) \
|
|
{ \
|
|
check_memory_region_inline(addr, size, true, _RET_IP_); \
|
|
} \
|
|
EXPORT_SYMBOL(__asan_store##size); \
|
|
__alias(__asan_store##size) \
|
|
void __asan_store##size##_noabort(unsigned long); \
|
|
EXPORT_SYMBOL(__asan_store##size##_noabort)
|
|
|
|
DEFINE_ASAN_LOAD_STORE(1);
|
|
DEFINE_ASAN_LOAD_STORE(2);
|
|
DEFINE_ASAN_LOAD_STORE(4);
|
|
DEFINE_ASAN_LOAD_STORE(8);
|
|
DEFINE_ASAN_LOAD_STORE(16);
|
|
|
|
void __asan_loadN(unsigned long addr, size_t size)
|
|
{
|
|
check_memory_region(addr, size, false, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__asan_loadN);
|
|
|
|
__alias(__asan_loadN)
|
|
void __asan_loadN_noabort(unsigned long, size_t);
|
|
EXPORT_SYMBOL(__asan_loadN_noabort);
|
|
|
|
void __asan_storeN(unsigned long addr, size_t size)
|
|
{
|
|
check_memory_region(addr, size, true, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__asan_storeN);
|
|
|
|
__alias(__asan_storeN)
|
|
void __asan_storeN_noabort(unsigned long, size_t);
|
|
EXPORT_SYMBOL(__asan_storeN_noabort);
|
|
|
|
/* to shut up compiler complaints */
|
|
void __asan_handle_no_return(void) {}
|
|
EXPORT_SYMBOL(__asan_handle_no_return);
|
|
|
|
/* Emitted by compiler to poison large objects when they go out of scope. */
|
|
void __asan_poison_stack_memory(const void *addr, size_t size)
|
|
{
|
|
/*
|
|
* Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded
|
|
* by redzones, so we simply round up size to simplify logic.
|
|
*/
|
|
kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE),
|
|
KASAN_USE_AFTER_SCOPE);
|
|
}
|
|
EXPORT_SYMBOL(__asan_poison_stack_memory);
|
|
|
|
/* Emitted by compiler to unpoison large objects when they go into scope. */
|
|
void __asan_unpoison_stack_memory(const void *addr, size_t size)
|
|
{
|
|
kasan_unpoison_shadow(addr, size);
|
|
}
|
|
EXPORT_SYMBOL(__asan_unpoison_stack_memory);
|
|
|
|
/* Emitted by compiler to poison alloca()ed objects. */
|
|
void __asan_alloca_poison(unsigned long addr, size_t size)
|
|
{
|
|
size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
|
|
size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) -
|
|
rounded_up_size;
|
|
size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE);
|
|
|
|
const void *left_redzone = (const void *)(addr -
|
|
KASAN_ALLOCA_REDZONE_SIZE);
|
|
const void *right_redzone = (const void *)(addr + rounded_up_size);
|
|
|
|
WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
|
|
|
|
kasan_unpoison_shadow((const void *)(addr + rounded_down_size),
|
|
size - rounded_down_size);
|
|
kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
|
|
KASAN_ALLOCA_LEFT);
|
|
kasan_poison_shadow(right_redzone,
|
|
padding_size + KASAN_ALLOCA_REDZONE_SIZE,
|
|
KASAN_ALLOCA_RIGHT);
|
|
}
|
|
EXPORT_SYMBOL(__asan_alloca_poison);
|
|
|
|
/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */
|
|
void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
|
|
{
|
|
if (unlikely(!stack_top || stack_top > stack_bottom))
|
|
return;
|
|
|
|
kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
|
|
}
|
|
EXPORT_SYMBOL(__asan_allocas_unpoison);
|
|
|
|
/* Emitted by the compiler to [un]poison local variables. */
|
|
#define DEFINE_ASAN_SET_SHADOW(byte) \
|
|
void __asan_set_shadow_##byte(const void *addr, size_t size) \
|
|
{ \
|
|
__memset((void *)addr, 0x##byte, size); \
|
|
} \
|
|
EXPORT_SYMBOL(__asan_set_shadow_##byte)
|
|
|
|
DEFINE_ASAN_SET_SHADOW(00);
|
|
DEFINE_ASAN_SET_SHADOW(f1);
|
|
DEFINE_ASAN_SET_SHADOW(f2);
|
|
DEFINE_ASAN_SET_SHADOW(f3);
|
|
DEFINE_ASAN_SET_SHADOW(f5);
|
|
DEFINE_ASAN_SET_SHADOW(f8);
|
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG
|
|
static bool shadow_mapped(unsigned long addr)
|
|
{
|
|
pgd_t *pgd = pgd_offset_k(addr);
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
|
|
if (pgd_none(*pgd))
|
|
return false;
|
|
p4d = p4d_offset(pgd, addr);
|
|
if (p4d_none(*p4d))
|
|
return false;
|
|
pud = pud_offset(p4d, addr);
|
|
if (pud_none(*pud))
|
|
return false;
|
|
|
|
/*
|
|
* We can't use pud_large() or pud_huge(), the first one is
|
|
* arch-specific, the last one depends on HUGETLB_PAGE. So let's abuse
|
|
* pud_bad(), if pud is bad then it's bad because it's huge.
|
|
*/
|
|
if (pud_bad(*pud))
|
|
return true;
|
|
pmd = pmd_offset(pud, addr);
|
|
if (pmd_none(*pmd))
|
|
return false;
|
|
|
|
if (pmd_bad(*pmd))
|
|
return true;
|
|
pte = pte_offset_kernel(pmd, addr);
|
|
return !pte_none(*pte);
|
|
}
|
|
|
|
static int __meminit kasan_mem_notifier(struct notifier_block *nb,
|
|
unsigned long action, void *data)
|
|
{
|
|
struct memory_notify *mem_data = data;
|
|
unsigned long nr_shadow_pages, start_kaddr, shadow_start;
|
|
unsigned long shadow_end, shadow_size;
|
|
|
|
nr_shadow_pages = mem_data->nr_pages >> KASAN_SHADOW_SCALE_SHIFT;
|
|
start_kaddr = (unsigned long)pfn_to_kaddr(mem_data->start_pfn);
|
|
shadow_start = (unsigned long)kasan_mem_to_shadow((void *)start_kaddr);
|
|
shadow_size = nr_shadow_pages << PAGE_SHIFT;
|
|
shadow_end = shadow_start + shadow_size;
|
|
|
|
if (WARN_ON(mem_data->nr_pages % KASAN_SHADOW_SCALE_SIZE) ||
|
|
WARN_ON(start_kaddr % (KASAN_SHADOW_SCALE_SIZE << PAGE_SHIFT)))
|
|
return NOTIFY_BAD;
|
|
|
|
switch (action) {
|
|
case MEM_GOING_ONLINE: {
|
|
void *ret;
|
|
|
|
/*
|
|
* If shadow is mapped already than it must have been mapped
|
|
* during the boot. This could happen if we onlining previously
|
|
* offlined memory.
|
|
*/
|
|
if (shadow_mapped(shadow_start))
|
|
return NOTIFY_OK;
|
|
|
|
ret = __vmalloc_node_range(shadow_size, PAGE_SIZE, shadow_start,
|
|
shadow_end, GFP_KERNEL,
|
|
PAGE_KERNEL, VM_NO_GUARD,
|
|
pfn_to_nid(mem_data->start_pfn),
|
|
__builtin_return_address(0));
|
|
if (!ret)
|
|
return NOTIFY_BAD;
|
|
|
|
kmemleak_ignore(ret);
|
|
return NOTIFY_OK;
|
|
}
|
|
case MEM_CANCEL_ONLINE:
|
|
case MEM_OFFLINE: {
|
|
struct vm_struct *vm;
|
|
|
|
/*
|
|
* shadow_start was either mapped during boot by kasan_init()
|
|
* or during memory online by __vmalloc_node_range().
|
|
* In the latter case we can use vfree() to free shadow.
|
|
* Non-NULL result of the find_vm_area() will tell us if
|
|
* that was the second case.
|
|
*
|
|
* Currently it's not possible to free shadow mapped
|
|
* during boot by kasan_init(). It's because the code
|
|
* to do that hasn't been written yet. So we'll just
|
|
* leak the memory.
|
|
*/
|
|
vm = find_vm_area((void *)shadow_start);
|
|
if (vm)
|
|
vfree((void *)shadow_start);
|
|
}
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static int __init kasan_memhotplug_init(void)
|
|
{
|
|
hotplug_memory_notifier(kasan_mem_notifier, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
core_initcall(kasan_memhotplug_init);
|
|
#endif
|