lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 11 Aug 2021 21:30:06 +0200 From: andrey.konovalov@...ux.dev To: Andrew Morton <akpm@...ux-foundation.org> Cc: Andrey Konovalov <andreyknvl@...il.com>, Andrey Ryabinin <aryabinin@...tuozzo.com>, Marco Elver <elver@...gle.com>, Dmitry Vyukov <dvyukov@...gle.com>, Alexander Potapenko <glider@...gle.com>, kasan-dev@...glegroups.com, linux-mm@...ck.org, linux-kernel@...r.kernel.org Subject: [PATCH 7/8] kasan: test: avoid corrupting memory in copy_user_test From: Andrey Konovalov <andreyknvl@...il.com> 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. Signed-off-by: Andrey Konovalov <andreyknvl@...il.com> --- 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); -- 2.25.1
Powered by blists - more mailing lists