+ kasan-add-test-for-invalid-size-in-memmove.patch added to -mm tree

+ kasan-add-test-for-invalid-size-in-memmove.patch added to -mm tree

[akpm]

The patch titled
     Subject: kasan: add test for invalid size in memmove
has been added to the -mm tree.  Its filename is
     kasan-add-test-for-invalid-size-in-memmove.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/kasan-add-test-for-invalid-size-in-memmove.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/kasan-add-test-for-invalid-size-in-memmove.patch

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------------------------------------------------------
From: Walter Wu <walter-zh.wu@mediatek.com>
Subject: kasan: add test for invalid size in memmove

Test negative size in memmove in order to verify whether it correctly get
KASAN report.

Casting negative numbers to size_t would indeed turn up as a large size_t,
so it will have out-of-bounds bug and be detected by KASAN.

Link: http://lkml.kernel.org/r/20191112065313.7060-1-walter-zh.wu@mediatek.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/test_kasan.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

--- a/lib/test_kasan.c~kasan-add-test-for-invalid-size-in-memmove
+++ a/lib/test_kasan.c
@@ -285,6 +285,23 @@ static noinline void __init kmalloc_oob_
 	kfree(ptr);
 }
 
+static noinline void __init kmalloc_memmove_invalid_size(void)
+{
+	char *ptr;
+	size_t size = 64;
+
+	pr_info("invalid size in memmove\n");
+	ptr = kmalloc(size, GFP_KERNEL);
+	if (!ptr) {
+		pr_err("Allocation failed\n");
+		return;
+	}
+
+	memset((char *)ptr, 0, 64);
+	memmove((char *)ptr, (char *)ptr + 4, -2);
+	kfree(ptr);
+}
+
 static noinline void __init kmalloc_uaf(void)
 {
 	char *ptr;
@@ -799,6 +816,7 @@ static int __init kmalloc_tests_init(voi
 	kmalloc_oob_memset_4();
 	kmalloc_oob_memset_8();
 	kmalloc_oob_memset_16();
+	kmalloc_memmove_invalid_size();
 	kmalloc_uaf();
 	kmalloc_uaf_memset();
 	kmalloc_uaf2();
_

Patches currently in -mm which might be from walter-zh.wu@mediatek.com are

kasan-detect-negative-size-in-memory-operation-function.patch
kasan-add-test-for-invalid-size-in-memmove.patch