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authorDmitry Vyukov <dvyukov@google.com>2016-11-30 15:54:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-11-30 16:32:52 -0800
commit828347f8f9a558cf1af2faa46387a26564f2ac3e (patch)
tree4acb63366cc89b3e87e85805530911300dd4ab19 /lib
parent045d599a286bc01daa3510d59272440a17b23c2e (diff)
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kasan: support use-after-scope detection
Gcc revision 241896 implements use-after-scope detection. Will be available in gcc 7. Support it in KASAN. Gcc emits 2 new callbacks to poison/unpoison large stack objects when they go in/out of scope. Implement the callbacks and add a test. [dvyukov@google.com: v3] Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/test_kasan.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 5e51872b3fc1..fbdf87920093 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -20,6 +20,11 @@
#include <linux/uaccess.h>
#include <linux/module.h>
+/*
+ * Note: test functions are marked noinline so that their names appear in
+ * reports.
+ */
+
static noinline void __init kmalloc_oob_right(void)
{
char *ptr;
@@ -411,6 +416,29 @@ static noinline void __init copy_user_test(void)
kfree(kmem);
}
+static noinline void __init use_after_scope_test(void)
+{
+ volatile char *volatile p;
+
+ pr_info("use-after-scope on int\n");
+ {
+ int local = 0;
+
+ p = (char *)&local;
+ }
+ p[0] = 1;
+ p[3] = 1;
+
+ pr_info("use-after-scope on array\n");
+ {
+ char local[1024] = {0};
+
+ p = local;
+ }
+ p[0] = 1;
+ p[1023] = 1;
+}
+
static int __init kmalloc_tests_init(void)
{
kmalloc_oob_right();
@@ -436,6 +464,7 @@ static int __init kmalloc_tests_init(void)
kasan_global_oob();
ksize_unpoisons_memory();
copy_user_test();
+ use_after_scope_test();
return -EAGAIN;
}