From: Kees Cook <keescook@xxxxxxxxxxxx>
Upstream commit: 69d0db01e210 ("ubsan: remove CONFIG_UBSAN_OBJECT_SIZE")
The object-size sanitizer is redundant to -Warray-bounds, and
inappropriately performs its checks at run-time when all information
needed for the evaluation is available at compile-time, making it quite
difficult to use:
https://bugzilla.kernel.org/show_bug.cgi?id=214861
This run-time object-size checks also trigger false-positive errors,
like the below, that make it quite difficult to test stable kernels in
test automations like syzkaller:
https://syzkaller.appspot.com/text?tag=Error&x=12b3aac3700000
With -Warray-bounds almost enabled globally, it doesn't make sense to
keep this around.
Link: https://lkml.kernel.org/r/20211203235346.110809-1-keescook@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Michal Marek <michal.lkml@xxxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxxx>
---
lib/test_ubsan.c | 11 -----------
scripts/Makefile.ubsan | 1 -
2 files changed, 12 deletions(-)
diff --git a/lib/test_ubsan.c b/lib/test_ubsan.c
index 9ea10adf7a66..b1d0a6ecfe1b 100644
--- a/lib/test_ubsan.c
+++ b/lib/test_ubsan.c
@@ -89,16 +89,6 @@ static void test_ubsan_misaligned_access(void)
*ptr = val;
}
-static void test_ubsan_object_size_mismatch(void)
-{
- /* "((aligned(8)))" helps this not into be misaligned for ptr-access. */
- volatile int val __aligned(8) = 4;
- volatile long long *ptr, val2;
-
- ptr = (long long *)&val;
- val2 = *ptr;
-}
-
static const test_ubsan_fp test_ubsan_array[] = {
test_ubsan_add_overflow,
test_ubsan_sub_overflow,
@@ -110,7 +100,6 @@ static const test_ubsan_fp test_ubsan_array[] = {
test_ubsan_load_invalid_value,
//test_ubsan_null_ptr_deref, /* exclude it because there is a crash */
test_ubsan_misaligned_access,
- test_ubsan_object_size_mismatch,
};
static int __init test_ubsan_init(void)
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 9716dab06bc7..2156e18391a3 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -23,7 +23,6 @@ ifdef CONFIG_UBSAN_MISC
CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum)
endif
--
2.35.1
