The patch titled
Subject: kasan: test: avoid corrupting memory in copy_user_test
has been added to the -mm tree. Its filename is
kasan-test-avoid-corrupting-memory-in-copy_user_test.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-test-avoid-corrupting-memory-in-copy_user_test.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-test-avoid-corrupting-memory-in-copy_user_test.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Subject: kasan: test: avoid corrupting memory in copy_user_test
copy_user_test() does writes past the allocated object. As the result, it
corrupts kernel memory, which might lead to crashes with the HW_TAGS mode,
as it neither uses quarantine nor redzones.
(Technically, this test can't yet be enabled with the HW_TAGS mode, but
this will be implemented in the future.)
Adjust the test to only write memory within the aligned kmalloc object.
Link: https://lkml.kernel.org/r/19bf3a5112ee65b7db88dc731643b657b816c5e8.1628779805.git.andreyknvl@xxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_kasan_module.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
--- a/lib/test_kasan_module.c~kasan-test-avoid-corrupting-memory-in-copy_user_test
+++ a/lib/test_kasan_module.c
@@ -15,13 +15,11 @@
#include "../mm/kasan/kasan.h"
-#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
-
static noinline void __init copy_user_test(void)
{
char *kmem;
char __user *usermem;
- size_t size = 10;
+ size_t size = 128 - KASAN_GRANULE_SIZE;
int __maybe_unused unused;
kmem = kmalloc(size, GFP_KERNEL);
@@ -38,25 +36,25 @@ static noinline void __init copy_user_te
}
pr_info("out-of-bounds in copy_from_user()\n");
- unused = copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
+ unused = copy_from_user(kmem, usermem, size + 1);
pr_info("out-of-bounds in copy_to_user()\n");
- unused = copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
+ unused = copy_to_user(usermem, kmem, size + 1);
pr_info("out-of-bounds in __copy_from_user()\n");
- unused = __copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
+ unused = __copy_from_user(kmem, usermem, size + 1);
pr_info("out-of-bounds in __copy_to_user()\n");
- unused = __copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
+ unused = __copy_to_user(usermem, kmem, size + 1);
pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
- unused = __copy_from_user_inatomic(kmem, usermem, size + 1 + OOB_TAG_OFF);
+ unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
- unused = __copy_to_user_inatomic(usermem, kmem, size + 1 + OOB_TAG_OFF);
+ unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
pr_info("out-of-bounds in strncpy_from_user()\n");
- unused = strncpy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
+ unused = strncpy_from_user(kmem, usermem, size + 1);
vm_munmap((unsigned long)usermem, PAGE_SIZE);
kfree(kmem);
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxx are
kasan-test-rework-kmalloc_oob_right.patch
kasan-test-avoid-writing-invalid-memory.patch
kasan-test-avoid-corrupting-memory-via-memset.patch
kasan-test-disable-kmalloc_memmove_invalid_size-for-hw_tags.patch
kasan-test-only-do-kmalloc_uaf_memset-for-generic-mode.patch
kasan-test-clean-up-ksize_uaf.patch
kasan-test-avoid-corrupting-memory-in-copy_user_test.patch
kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf.patch
