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kasan: move common generic and tag-based code to common.c
Tag-based KASAN reuses a significant part of the generic KASAN code, so move the common parts to common.c without any functional changes. Link: http://lkml.kernel.org/r/114064d002356e03bb8cc91f7835e20dc61b51d9.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrey Konovalov
Linus Torvalds
parent
12b2238699
commit
bffa986c6f
@ -1,11 +1,14 @@
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# SPDX-License-Identifier: GPL-2.0
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KASAN_SANITIZE := n
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UBSAN_SANITIZE_common.o := n
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UBSAN_SANITIZE_kasan.o := n
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KCOV_INSTRUMENT := n
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CFLAGS_REMOVE_kasan.o = -pg
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# Function splitter causes unnecessary splits in __asan_load1/__asan_store1
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# see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
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CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
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CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
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obj-y := kasan.o report.o kasan_init.o quarantine.o
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obj-y := common.o kasan.o report.o kasan_init.o quarantine.o
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603
mm/kasan/common.c
Normal file
603
mm/kasan/common.c
Normal file
@ -0,0 +1,603 @@
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/*
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* This file contains common generic and tag-based KASAN 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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#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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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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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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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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/*
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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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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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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 inline 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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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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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_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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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 (void *)object;
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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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return (void *)object;
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}
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void *kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags)
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{
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return kasan_kmalloc(cache, object, cache->object_size, flags);
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}
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static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
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unsigned long ip, bool quarantine)
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{
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s8 shadow_byte;
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unsigned long rounded_up_size;
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if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
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object)) {
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kasan_report_invalid_free(object, ip);
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return true;
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}
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/* RCU slabs could be legally used after free within the RCU period */
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if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
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return false;
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shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object));
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if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) {
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kasan_report_invalid_free(object, ip);
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return true;
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}
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rounded_up_size = round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE);
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kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
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if (!quarantine || unlikely(!(cache->flags & SLAB_KASAN)))
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return false;
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set_track(&get_alloc_info(cache, object)->free_track, GFP_NOWAIT);
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quarantine_put(get_free_info(cache, object), cache);
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return true;
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}
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bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
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{
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return __kasan_slab_free(cache, object, ip, true);
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}
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void *kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size,
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gfp_t flags)
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{
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unsigned long redzone_start;
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unsigned long redzone_end;
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if (gfpflags_allow_blocking(flags))
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quarantine_reduce();
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if (unlikely(object == NULL))
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return NULL;
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redzone_start = round_up((unsigned long)(object + size),
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KASAN_SHADOW_SCALE_SIZE);
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redzone_end = round_up((unsigned long)object + cache->object_size,
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KASAN_SHADOW_SCALE_SIZE);
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kasan_unpoison_shadow(object, size);
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kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
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KASAN_KMALLOC_REDZONE);
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if (cache->flags & SLAB_KASAN)
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set_track(&get_alloc_info(cache, object)->alloc_track, flags);
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return (void *)object;
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}
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EXPORT_SYMBOL(kasan_kmalloc);
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void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
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{
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struct page *page;
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unsigned long redzone_start;
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unsigned long redzone_end;
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if (gfpflags_allow_blocking(flags))
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quarantine_reduce();
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if (unlikely(ptr == NULL))
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return NULL;
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page = virt_to_page(ptr);
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redzone_start = round_up((unsigned long)(ptr + size),
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KASAN_SHADOW_SCALE_SIZE);
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redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page));
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kasan_unpoison_shadow(ptr, size);
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kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
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KASAN_PAGE_REDZONE);
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return (void *)ptr;
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}
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void *kasan_krealloc(const void *object, size_t size, gfp_t flags)
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{
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struct page *page;
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if (unlikely(object == ZERO_SIZE_PTR))
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return (void *)object;
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page = virt_to_head_page(object);
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if (unlikely(!PageSlab(page)))
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return kasan_kmalloc_large(object, size, flags);
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else
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return kasan_kmalloc(page->slab_cache, object, size, flags);
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}
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void kasan_poison_kfree(void *ptr, unsigned long ip)
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{
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struct page *page;
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||||
|
||||
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));
|
||||
}
|
||||
|
||||
#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
|
||||
570
mm/kasan/kasan.c
570
mm/kasan/kasan.c
@ -1,5 +1,5 @@
|
||||
/*
|
||||
* This file contains shadow memory manipulation code.
|
||||
* This file contains core KASAN code.
|
||||
*
|
||||
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
|
||||
* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
|
||||
@ -40,82 +40,6 @@
|
||||
#include "kasan.h"
|
||||
#include "../slab.h"
|
||||
|
||||
void kasan_enable_current(void)
|
||||
{
|
||||
current->kasan_depth++;
|
||||
}
|
||||
|
||||
void kasan_disable_current(void)
|
||||
{
|
||||
current->kasan_depth--;
|
||||
}
|
||||
|
||||
/*
|
||||
* Poisons the shadow memory for 'size' bytes starting from 'addr'.
|
||||
* Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE.
|
||||
*/
|
||||
static void kasan_poison_shadow(const void *address, size_t size, u8 value)
|
||||
{
|
||||
void *shadow_start, *shadow_end;
|
||||
|
||||
shadow_start = kasan_mem_to_shadow(address);
|
||||
shadow_end = kasan_mem_to_shadow(address + size);
|
||||
|
||||
memset(shadow_start, value, shadow_end - shadow_start);
|
||||
}
|
||||
|
||||
void kasan_unpoison_shadow(const void *address, size_t size)
|
||||
{
|
||||
kasan_poison_shadow(address, size, 0);
|
||||
|
||||
if (size & KASAN_SHADOW_MASK) {
|
||||
u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
|
||||
*shadow = size & KASAN_SHADOW_MASK;
|
||||
}
|
||||
}
|
||||
|
||||
static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
|
||||
{
|
||||
void *base = task_stack_page(task);
|
||||
size_t size = sp - base;
|
||||
|
||||
kasan_unpoison_shadow(base, size);
|
||||
}
|
||||
|
||||
/* Unpoison the entire stack for a task. */
|
||||
void kasan_unpoison_task_stack(struct task_struct *task)
|
||||
{
|
||||
__kasan_unpoison_stack(task, task_stack_page(task) + THREAD_SIZE);
|
||||
}
|
||||
|
||||
/* Unpoison the stack for the current task beyond a watermark sp value. */
|
||||
asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
|
||||
{
|
||||
/*
|
||||
* Calculate the task stack base address. Avoid using 'current'
|
||||
* because this function is called by early resume code which hasn't
|
||||
* yet set up the percpu register (%gs).
|
||||
*/
|
||||
void *base = (void *)((unsigned long)watermark & ~(THREAD_SIZE - 1));
|
||||
|
||||
kasan_unpoison_shadow(base, watermark - base);
|
||||
}
|
||||
|
||||
/*
|
||||
* Clear all poison for the region between the current SP and a provided
|
||||
* watermark value, as is sometimes required prior to hand-crafted asm function
|
||||
* returns in the middle of functions.
|
||||
*/
|
||||
void kasan_unpoison_stack_above_sp_to(const void *watermark)
|
||||
{
|
||||
const void *sp = __builtin_frame_address(0);
|
||||
size_t size = watermark - sp;
|
||||
|
||||
if (WARN_ON(sp > watermark))
|
||||
return;
|
||||
kasan_unpoison_shadow(sp, size);
|
||||
}
|
||||
|
||||
/*
|
||||
* All functions below always inlined so compiler could
|
||||
* perform better optimizations in each of __asan_loadX/__assn_storeX
|
||||
@ -260,121 +184,12 @@ static __always_inline void check_memory_region_inline(unsigned long addr,
|
||||
kasan_report(addr, size, write, ret_ip);
|
||||
}
|
||||
|
||||
static void check_memory_region(unsigned long addr,
|
||||
size_t size, bool write,
|
||||
void check_memory_region(unsigned long addr, size_t size, bool write,
|
||||
unsigned long ret_ip)
|
||||
{
|
||||
check_memory_region_inline(addr, size, write, ret_ip);
|
||||
}
|
||||
|
||||
void kasan_check_read(const volatile void *p, unsigned int size)
|
||||
{
|
||||
check_memory_region((unsigned long)p, size, false, _RET_IP_);
|
||||
}
|
||||
EXPORT_SYMBOL(kasan_check_read);
|
||||
|
||||
void kasan_check_write(const volatile void *p, unsigned int size)
|
||||
{
|
||||
check_memory_region((unsigned long)p, size, true, _RET_IP_);
|
||||
}
|
||||
EXPORT_SYMBOL(kasan_check_write);
|
||||
|
||||
#undef memset
|
||||
void *memset(void *addr, int c, size_t len)
|
||||
{
|
||||
check_memory_region((unsigned long)addr, len, true, _RET_IP_);
|
||||
|
||||
return __memset(addr, c, len);
|
||||
}
|
||||
|
||||
#undef memmove
|
||||
void *memmove(void *dest, const void *src, size_t len)
|
||||
{
|
||||
check_memory_region((unsigned long)src, len, false, _RET_IP_);
|
||||
check_memory_region((unsigned long)dest, len, true, _RET_IP_);
|
||||
|
||||
return __memmove(dest, src, len);
|
||||
}
|
||||
|
||||
#undef memcpy
|
||||
void *memcpy(void *dest, const void *src, size_t len)
|
||||
{
|
||||
check_memory_region((unsigned long)src, len, false, _RET_IP_);
|
||||
check_memory_region((unsigned long)dest, len, true, _RET_IP_);
|
||||
|
||||
return __memcpy(dest, src, len);
|
||||
}
|
||||
|
||||
void kasan_alloc_pages(struct page *page, unsigned int order)
|
||||
{
|
||||
if (likely(!PageHighMem(page)))
|
||||
kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
|
||||
}
|
||||
|
||||
void kasan_free_pages(struct page *page, unsigned int order)
|
||||
{
|
||||
if (likely(!PageHighMem(page)))
|
||||
kasan_poison_shadow(page_address(page),
|
||||
PAGE_SIZE << order,
|
||||
KASAN_FREE_PAGE);
|
||||
}
|
||||
|
||||
/*
|
||||
* Adaptive redzone policy taken from the userspace AddressSanitizer runtime.
|
||||
* For larger allocations larger redzones are used.
|
||||
*/
|
||||
static unsigned int optimal_redzone(unsigned int object_size)
|
||||
{
|
||||
return
|
||||
object_size <= 64 - 16 ? 16 :
|
||||
object_size <= 128 - 32 ? 32 :
|
||||
object_size <= 512 - 64 ? 64 :
|
||||
object_size <= 4096 - 128 ? 128 :
|
||||
object_size <= (1 << 14) - 256 ? 256 :
|
||||
object_size <= (1 << 15) - 512 ? 512 :
|
||||
object_size <= (1 << 16) - 1024 ? 1024 : 2048;
|
||||
}
|
||||
|
||||
void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
|
||||
slab_flags_t *flags)
|
||||
{
|
||||
unsigned int orig_size = *size;
|
||||
int redzone_adjust;
|
||||
|
||||
/* Add alloc meta. */
|
||||
cache->kasan_info.alloc_meta_offset = *size;
|
||||
*size += sizeof(struct kasan_alloc_meta);
|
||||
|
||||
/* Add free meta. */
|
||||
if (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor ||
|
||||
cache->object_size < sizeof(struct kasan_free_meta)) {
|
||||
cache->kasan_info.free_meta_offset = *size;
|
||||
*size += sizeof(struct kasan_free_meta);
|
||||
}
|
||||
redzone_adjust = optimal_redzone(cache->object_size) -
|
||||
(*size - cache->object_size);
|
||||
|
||||
if (redzone_adjust > 0)
|
||||
*size += redzone_adjust;
|
||||
|
||||
*size = min_t(unsigned int, KMALLOC_MAX_SIZE,
|
||||
max(*size, cache->object_size +
|
||||
optimal_redzone(cache->object_size)));
|
||||
|
||||
/*
|
||||
* If the metadata doesn't fit, don't enable KASAN at all.
|
||||
*/
|
||||
if (*size <= cache->kasan_info.alloc_meta_offset ||
|
||||
*size <= cache->kasan_info.free_meta_offset) {
|
||||
cache->kasan_info.alloc_meta_offset = 0;
|
||||
cache->kasan_info.free_meta_offset = 0;
|
||||
*size = orig_size;
|
||||
return;
|
||||
}
|
||||
|
||||
*flags |= SLAB_KASAN;
|
||||
}
|
||||
|
||||
void kasan_cache_shrink(struct kmem_cache *cache)
|
||||
{
|
||||
quarantine_remove_cache(cache);
|
||||
@ -386,277 +201,6 @@ void kasan_cache_shutdown(struct kmem_cache *cache)
|
||||
quarantine_remove_cache(cache);
|
||||
}
|
||||
|
||||
size_t kasan_metadata_size(struct kmem_cache *cache)
|
||||
{
|
||||
return (cache->kasan_info.alloc_meta_offset ?
|
||||
sizeof(struct kasan_alloc_meta) : 0) +
|
||||
(cache->kasan_info.free_meta_offset ?
|
||||
sizeof(struct kasan_free_meta) : 0);
|
||||
}
|
||||
|
||||
void kasan_poison_slab(struct page *page)
|
||||
{
|
||||
kasan_poison_shadow(page_address(page),
|
||||
PAGE_SIZE << compound_order(page),
|
||||
KASAN_KMALLOC_REDZONE);
|
||||
}
|
||||
|
||||
void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
|
||||
{
|
||||
kasan_unpoison_shadow(object, cache->object_size);
|
||||
}
|
||||
|
||||
void kasan_poison_object_data(struct kmem_cache *cache, void *object)
|
||||
{
|
||||
kasan_poison_shadow(object,
|
||||
round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
|
||||
KASAN_KMALLOC_REDZONE);
|
||||
}
|
||||
|
||||
static inline int in_irqentry_text(unsigned long ptr)
|
||||
{
|
||||
return (ptr >= (unsigned long)&__irqentry_text_start &&
|
||||
ptr < (unsigned long)&__irqentry_text_end) ||
|
||||
(ptr >= (unsigned long)&__softirqentry_text_start &&
|
||||
ptr < (unsigned long)&__softirqentry_text_end);
|
||||
}
|
||||
|
||||
static inline void filter_irq_stacks(struct stack_trace *trace)
|
||||
{
|
||||
int i;
|
||||
|
||||
if (!trace->nr_entries)
|
||||
return;
|
||||
for (i = 0; i < trace->nr_entries; i++)
|
||||
if (in_irqentry_text(trace->entries[i])) {
|
||||
/* Include the irqentry function into the stack. */
|
||||
trace->nr_entries = i + 1;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
static inline depot_stack_handle_t save_stack(gfp_t flags)
|
||||
{
|
||||
unsigned long entries[KASAN_STACK_DEPTH];
|
||||
struct stack_trace trace = {
|
||||
.nr_entries = 0,
|
||||
.entries = entries,
|
||||
.max_entries = KASAN_STACK_DEPTH,
|
||||
.skip = 0
|
||||
};
|
||||
|
||||
save_stack_trace(&trace);
|
||||
filter_irq_stacks(&trace);
|
||||
if (trace.nr_entries != 0 &&
|
||||
trace.entries[trace.nr_entries-1] == ULONG_MAX)
|
||||
trace.nr_entries--;
|
||||
|
||||
return depot_save_stack(&trace, flags);
|
||||
}
|
||||
|
||||
static inline void set_track(struct kasan_track *track, gfp_t flags)
|
||||
{
|
||||
track->pid = current->pid;
|
||||
track->stack = save_stack(flags);
|
||||
}
|
||||
|
||||
struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
|
||||
const void *object)
|
||||
{
|
||||
BUILD_BUG_ON(sizeof(struct kasan_alloc_meta) > 32);
|
||||
return (void *)object + cache->kasan_info.alloc_meta_offset;
|
||||
}
|
||||
|
||||
struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
|
||||
const void *object)
|
||||
{
|
||||
BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
|
||||
return (void *)object + cache->kasan_info.free_meta_offset;
|
||||
}
|
||||
|
||||
void *kasan_init_slab_obj(struct kmem_cache *cache, const void *object)
|
||||
{
|
||||
struct kasan_alloc_meta *alloc_info;
|
||||
|
||||
if (!(cache->flags & SLAB_KASAN))
|
||||
return (void *)object;
|
||||
|
||||
alloc_info = get_alloc_info(cache, object);
|
||||
__memset(alloc_info, 0, sizeof(*alloc_info));
|
||||
|
||||
return (void *)object;
|
||||
}
|
||||
|
||||
void *kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags)
|
||||
{
|
||||
return 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 NULL;
|
||||
|
||||
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);
|
||||
|
||||
return (void *)object;
|
||||
}
|
||||
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 NULL;
|
||||
|
||||
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);
|
||||
|
||||
return (void *)ptr;
|
||||
}
|
||||
|
||||
void *kasan_krealloc(const void *object, size_t size, gfp_t flags)
|
||||
{
|
||||
struct page *page;
|
||||
|
||||
if (unlikely(object == ZERO_SIZE_PTR))
|
||||
return ZERO_SIZE_PTR;
|
||||
|
||||
page = virt_to_head_page(object);
|
||||
|
||||
if (unlikely(!PageSlab(page)))
|
||||
return kasan_kmalloc_large(object, size, flags);
|
||||
else
|
||||
return 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);
|
||||
@ -797,113 +341,3 @@ 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
|
||||
|
||||
@ -105,6 +105,11 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
|
||||
<< KASAN_SHADOW_SCALE_SHIFT);
|
||||
}
|
||||
|
||||
void kasan_poison_shadow(const void *address, size_t size, u8 value);
|
||||
|
||||
void check_memory_region(unsigned long addr, size_t size, bool write,
|
||||
unsigned long ret_ip);
|
||||
|
||||
void kasan_report(unsigned long addr, size_t size,
|
||||
bool is_write, unsigned long ip);
|
||||
void kasan_report_invalid_free(void *object, unsigned long ip);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user