From: Andrey Konovalov andreyknvl@gmail.com
[ Upstream commit 756e5a47a5ddf0caa3708f922385a92af9d330b5 ]
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/19bf3a5112ee65b7db88dc731643b657b816c5e8.162877980... Signed-off-by: Andrey Konovalov andreyknvl@gmail.com Reviewed-by: Marco Elver elver@google.com Cc: Alexander Potapenko glider@google.com Cc: Andrey Ryabinin aryabinin@virtuozzo.com Cc: Dmitry Vyukov dvyukov@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- lib/test_kasan_module.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c index f1017f345d6c..fa73b9df0be4 100644 --- a/lib/test_kasan_module.c +++ b/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_test(void) }
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);