@@ -738,7 +738,8 @@ __FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp
if (__compiletime_lessthan(p_size, size))
__read_overflow();
if (p_size < size)
- fortify_panic(FORTIFY_FUNC_kmemdup, FORTIFY_READ, p_size, size, NULL);
+ fortify_panic(FORTIFY_FUNC_kmemdup, FORTIFY_READ, p_size, size,
+ __real_kmemdup(p, 0, gfp));
return __real_kmemdup(p, size, gfp);
}
@@ -1002,19 +1002,19 @@ static void fortify_test_kmemdup(struct kunit *test)
/* Out of bounds by 1 byte. */
copy = kmemdup(src, len + 1, GFP_KERNEL);
- KUNIT_EXPECT_NULL(test, copy);
+ KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
kfree(copy);
/* Way out of bounds. */
copy = kmemdup(src, len * 2, GFP_KERNEL);
- KUNIT_EXPECT_NULL(test, copy);
+ KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
kfree(copy);
/* Starting offset causing out of bounds. */
copy = kmemdup(src + 1, len, GFP_KERNEL);
- KUNIT_EXPECT_NULL(test, copy);
+ KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3);
kfree(copy);
}
The __alloc_size annotation for kmemdup() was getting disabled under KUnit testing because the replaced fortify_panic macro implementation was using "return NULL" as a way to survive the sanity checking. But having the chance to return NULL invalidated __alloc_size, so kmemdup was not passing the __builtin_dynamic_object_size() tests any more: [23:26:18] [PASSED] fortify_test_alloc_size_kmalloc_const [23:26:19] # fortify_test_alloc_size_kmalloc_dynamic: EXPECTATION FAILED at lib/fortify_kunit.c:265 [23:26:19] Expected __builtin_dynamic_object_size(p, 1) == expected, but [23:26:19] __builtin_dynamic_object_size(p, 1) == -1 (0xffffffffffffffff) [23:26:19] expected == 11 (0xb) [23:26:19] __alloc_size() not working with __bdos on kmemdup("hello there", len, gfp) [23:26:19] [FAILED] fortify_test_alloc_size_kmalloc_dynamic Normal builds were not affected: __alloc_size continued to work there. Use a zero-sized allocation instead, which allows __alloc_size to behave. Fixes: 4ce615e798a7 ("fortify: Provide KUnit counters for failure testing") Fixes: fa4a3f86d498 ("fortify: Add KUnit tests for runtime overflows") Signed-off-by: Kees Cook <keescook@chromium.org> --- Cc: linux-hardening@vger.kernel.org --- include/linux/fortify-string.h | 3 ++- lib/fortify_kunit.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-)