[Devel] [PATCH 24/39] kasan: enable stack instrumentation
Andrey Ryabinin
aryabinin at odin.com
Mon Aug 24 03:19:14 PDT 2015
From: Andrey Ryabinin <a.ryabinin at samsung.com>
commit c420f167db8c799d69fe43a801c58a7f02e9d57c upstream.
Stack instrumentation allows to detect out of bounds memory accesses for
variables allocated on stack. Compiler adds redzones around every
variable on stack and poisons redzones in function's prologue.
Such approach significantly increases stack usage, so all in-kernel stacks
size were doubled.
Signed-off-by: Andrey Ryabinin <a.ryabinin at samsung.com>
Cc: Dmitry Vyukov <dvyukov at google.com>
Cc: Konstantin Serebryany <kcc at google.com>
Cc: Dmitry Chernenkov <dmitryc at google.com>
Signed-off-by: Andrey Konovalov <adech.fo at gmail.com>
Cc: Yuri Gribov <tetra2005 at gmail.com>
Cc: Konstantin Khlebnikov <koct9i at gmail.com>
Cc: Sasha Levin <sasha.levin at oracle.com>
Cc: Christoph Lameter <cl at linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim at lge.com>
Cc: Dave Hansen <dave.hansen at intel.com>
Cc: Andi Kleen <andi at firstfloor.org>
Cc: Ingo Molnar <mingo at elte.hu>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: "H. Peter Anvin" <hpa at zytor.com>
Cc: Christoph Lameter <cl at linux.com>
Cc: Pekka Enberg <penberg at kernel.org>
Cc: David Rientjes <rientjes at google.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Andrey Ryabinin <aryabinin at odin.com>
---
arch/x86/include/asm/page_64_types.h | 12 +++++++++---
arch/x86/kernel/Makefile | 2 ++
arch/x86/mm/kasan_init_64.c | 11 +++++++++--
include/linux/init_task.h | 8 ++++++++
mm/kasan/kasan.h | 9 +++++++++
mm/kasan/report.c | 6 ++++++
scripts/Makefile.kasan | 1 +
7 files changed, 44 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 735457b..042942c 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -1,17 +1,23 @@
#ifndef _ASM_X86_PAGE_64_DEFS_H
#define _ASM_X86_PAGE_64_DEFS_H
-#define THREAD_SIZE_ORDER 2
+#ifdef CONFIG_KASAN
+#define KASAN_STACK_ORDER 1
+#else
+#define KASAN_STACK_ORDER 0
+#endif
+
+#define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER)
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#define CURRENT_MASK (~(THREAD_SIZE - 1))
-#define EXCEPTION_STACK_ORDER 0
+#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER)
#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
#define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1)
#define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER)
-#define IRQ_STACK_ORDER 2
+#define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER)
#define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER)
#define DOUBLEFAULT_STACK 1
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 102a138..4d5df57 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -17,6 +17,8 @@ CFLAGS_REMOVE_early_printk.o = -pg
endif
KASAN_SANITIZE_head$(BITS).o := n
+KASAN_SANITIZE_dumpstack.o := n
+KASAN_SANITIZE_dumpstack_$(BITS).o := n
CFLAGS_irq.o := -I$(src)/../include/asm/trace
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index cf3190a..a0c0dcc 100644
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -189,11 +189,18 @@ void __init kasan_init(void)
if (map_range(&pfn_mapped[i]))
panic("kasan: unable to allocate shadow!");
}
-
populate_zero_shadow(kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
- (void *)KASAN_SHADOW_END);
+ kasan_mem_to_shadow((void *)__START_KERNEL_map));
+
+ vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
+ (unsigned long)kasan_mem_to_shadow(_end),
+ NUMA_NO_NODE);
+
+ populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_VADDR),
+ (void *)KASAN_SHADOW_END);
memset(kasan_zero_page, 0, PAGE_SIZE);
load_cr3(init_level4_pgt);
+ init_task.kasan_depth = 0;
}
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index b1bdeb6..d2cbad0 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -161,6 +161,13 @@ extern struct task_group root_task_group;
#define INIT_TASK_COMM "swapper"
+#ifdef CONFIG_KASAN
+# define INIT_KASAN(tsk) \
+ .kasan_depth = 1,
+#else
+# define INIT_KASAN(tsk)
+#endif
+
/*
* INIT_TASK is used to set up the first task table, touch at
* your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -231,6 +238,7 @@ extern struct task_group root_task_group;
INIT_TASK_RCU_PREEMPT(tsk) \
INIT_CPUSET_SEQ \
INIT_VTIME(tsk) \
+ INIT_KASAN(tsk) \
}
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 5b052ab..1fcc1d8 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -12,6 +12,15 @@
#define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */
#define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */
+/*
+ * Stack redzone shadow values
+ * (Those are compiler's ABI, don't change them)
+ */
+#define KASAN_STACK_LEFT 0xF1
+#define KASAN_STACK_MID 0xF2
+#define KASAN_STACK_RIGHT 0xF3
+#define KASAN_STACK_PARTIAL 0xF4
+
struct kasan_access_info {
const void *access_addr;
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 2760edb..866732e 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -64,6 +64,12 @@ static void print_error_description(struct kasan_access_info *info)
case 0 ... KASAN_SHADOW_SCALE_SIZE - 1:
bug_type = "out of bounds access";
break;
+ case KASAN_STACK_LEFT:
+ case KASAN_STACK_MID:
+ case KASAN_STACK_RIGHT:
+ case KASAN_STACK_PARTIAL:
+ bug_type = "out of bounds on stack";
+ break;
}
pr_err("BUG: KASan: %s in %pS at addr %p\n",
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 7acd6fa..2163b8c 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -9,6 +9,7 @@ CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
-fasan-shadow-offset=$(CONFIG_KASAN_SHADOW_OFFSET) \
+ --param asan-stack=1 \
--param asan-instrumentation-with-call-threshold=$(call_threshold))
ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
--
2.4.6
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