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authorAndrey Konovalov <andreyknvl@google.com>2022-09-05 23:05:49 +0200
committerAndrew Morton <akpm@linux-foundation.org>2022-10-03 14:03:02 -0700
commit34b592ce5cc2dbd7d94812bff12ec32d3ec6f65c (patch)
tree7ddda5c1cab89e3a27393a5009965ee5f17b18cc /lib
parent1f538e1f2d294cf8a9486fb1a7d4d4f0d16e2b01 (diff)
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kasan: add another use-after-free test
Add a new use-after-free test that checks that KASAN detects use-after-free when another object was allocated in the same slot. This test is mainly relevant for the tag-based modes, which do not use quarantine. Once [1] is resolved, this test can be extended to check that the stack traces in the report point to the proper kmalloc/kfree calls. [1] https://bugzilla.kernel.org/show_bug.cgi?id=212203 Link: https://lkml.kernel.org/r/0659cfa15809dd38faa02bc0a59d0b5dbbd81211.1662411800.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/test_kasan.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 58c1b01ccfe2..505f77ffad27 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -612,6 +612,29 @@ again:
kfree(ptr2);
}
+/*
+ * Check that KASAN detects use-after-free when another object was allocated in
+ * the same slot. Relevant for the tag-based modes, which do not use quarantine.
+ */
+static void kmalloc_uaf3(struct kunit *test)
+{
+ char *ptr1, *ptr2;
+ size_t size = 100;
+
+ /* This test is specifically crafted for tag-based modes. */
+ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
+
+ ptr1 = kmalloc(size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
+ kfree(ptr1);
+
+ ptr2 = kmalloc(size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
+ kfree(ptr2);
+
+ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[8]);
+}
+
static void kfree_via_page(struct kunit *test)
{
char *ptr;
@@ -1382,6 +1405,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(kmalloc_uaf),
KUNIT_CASE(kmalloc_uaf_memset),
KUNIT_CASE(kmalloc_uaf2),
+ KUNIT_CASE(kmalloc_uaf3),
KUNIT_CASE(kfree_via_page),
KUNIT_CASE(kfree_via_phys),
KUNIT_CASE(kmem_cache_oob),