The patch titled
Subject: kasan: test: consolidate workarounds for unwanted __alloc_size() protection
has been added to the -mm tree. Its filename is
kasan-test-consolidate-workarounds-for-unwanted-__alloc_size-protection.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-test-consolidate-workarounds-for-unwanted-__alloc_size-protection.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-test-consolidate-workarounds-for-unwanted-__alloc_size-protection.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: kasan: test: consolidate workarounds for unwanted __alloc_size() protection
This fixes "lib/test_kasan.c: use underlying string helpers" to avoid
needing new helpers. As done in "kasan: test: bypass __alloc_size
checks", just use OPTIMIZER_HIDE_VAR(). Additionally converts a use of
"volatile", which was trying to work around similar detection.
Link: https://lkml.kernel.org/r/20211020193807.40684-1-keescook@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_kasan.c | 24 ++++++------------------
1 file changed, 6 insertions(+), 18 deletions(-)
--- a/lib/test_kasan.c~kasan-test-consolidate-workarounds-for-unwanted-__alloc_size-protection
+++ a/lib/test_kasan.c
@@ -525,12 +525,13 @@ static void kmalloc_memmove_invalid_size
{
char *ptr;
size_t size = 64;
- volatile size_t invalid_size = size;
+ size_t invalid_size = size;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
memset((char *)ptr, 0, 64);
+ OPTIMIZER_HIDE_VAR(invalid_size);
KUNIT_EXPECT_KASAN_FAIL(test,
memmove((char *)ptr, (char *)ptr + 4, invalid_size));
kfree(ptr);
@@ -852,21 +853,6 @@ static void kmem_cache_invalid_free(stru
kmem_cache_destroy(cache);
}
-/*
- * noinline wrappers to prevent the compiler from noticing the overflow
- * at compile time rather than having kasan catch it.
- */
-static noinline void *__kasan_memchr(const void *s, int c, size_t n)
-{
- return memchr(s, c, n);
-}
-
-static noinline int __kasan_memcmp(const void *s1, const void *s2, size_t n)
-{
- return memcmp(s1, s2, n);
-}
-
-
static void kasan_memchr(struct kunit *test)
{
char *ptr;
@@ -884,8 +870,9 @@ static void kasan_memchr(struct kunit *t
ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+ OPTIMIZER_HIDE_VAR(size);
KUNIT_EXPECT_KASAN_FAIL(test,
- kasan_ptr_result = __kasan_memchr(ptr, '1', size + 1));
+ kasan_ptr_result = memchr(ptr, '1', size + 1));
kfree(ptr);
}
@@ -909,8 +896,9 @@ static void kasan_memcmp(struct kunit *t
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
memset(arr, 0, sizeof(arr));
+ OPTIMIZER_HIDE_VAR(size);
KUNIT_EXPECT_KASAN_FAIL(test,
- kasan_int_result = __kasan_memcmp(ptr, arr, size+1));
+ kasan_int_result = memcmp(ptr, arr, size+1));
kfree(ptr);
}
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
kasan-test-bypass-__alloc_size-checks.patch
rapidio-avoid-bogus-__alloc_size-warning.patch
compiler-attributes-add-__alloc_size-for-better-bounds-checking.patch
slab-clean-up-function-prototypes.patch
slab-add-__alloc_size-attributes-for-better-bounds-checking.patch
mm-kvmalloc-add-__alloc_size-attributes-for-better-bounds-checking.patch
mm-vmalloc-add-__alloc_size-attributes-for-better-bounds-checking.patch
mm-page_alloc-add-__alloc_size-attributes-for-better-bounds-checking.patch
percpu-add-__alloc_size-attributes-for-better-bounds-checking.patch
kasan-test-consolidate-workarounds-for-unwanted-__alloc_size-protection.patch
maintainers-add-exec-binfmt-section-with-myself-and-eric.patch
binfmt_elf-reintroduce-using-map_fixed_noreplace.patch
