[PATCH v5 3/4] kasan: add tests for call_rcu stack recording

From: Walter Wu
Date: Wed May 20 2020 - 08:38:11 EST


Test call_rcu() call stack recording and verify whether it correctly
is printed in KASAN report.

Signed-off-by: Walter Wu <walter-zh.wu@xxxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
---
lib/test_kasan.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index e3087d90e00d..6e5fb05d42d8 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -792,6 +792,35 @@ static noinline void __init vmalloc_oob(void)
static void __init vmalloc_oob(void) {}
#endif

+static struct kasan_rcu_info {
+ int i;
+ struct rcu_head rcu;
+} *global_ptr;
+
+static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp)
+{
+ struct kasan_rcu_info *fp = container_of(rp,
+ struct kasan_rcu_info, rcu);
+
+ kfree(fp);
+ fp->i = 1;
+}
+
+static noinline void __init kasan_rcu_uaf(void)
+{
+ struct kasan_rcu_info *ptr;
+
+ pr_info("use-after-free in kasan_rcu_reclaim\n");
+ ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
+ if (!ptr) {
+ pr_err("Allocation failed\n");
+ return;
+ }
+
+ global_ptr = rcu_dereference_protected(ptr, NULL);
+ call_rcu(&global_ptr->rcu, kasan_rcu_reclaim);
+}
+
static int __init kmalloc_tests_init(void)
{
/*
@@ -839,6 +868,7 @@ static int __init kmalloc_tests_init(void)
kasan_bitops();
kmalloc_double_kzfree();
vmalloc_oob();
+ kasan_rcu_uaf();

kasan_restore_multi_shot(multishot);

--
2.18.0