From patchwork Sun Jul 14 17:04:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13732759 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 76D131E494; Sun, 14 Jul 2024 17:09:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720976943; cv=none; b=m5w972iwdKkaoJ/UP/T/oIEWoy+O7QPMWcWlyZvm/jVdR9zsbO1xhCZuu/m4Pq3i9TfqHp8CitKBw/txL5rrgzjOcN2pZDWLGAv3hIVKF2EMl9e+wX8S/2dhGKiSTkANSYkNeHpX8nff1ac3F9G56V86fcZ1kt/9LZPH6RGmmkM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720976943; c=relaxed/simple; bh=MxRLc97aWW1jnO5G6Jndd9uzcfVljas1IZvntva/lCs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=uK06dQXb2UWPsanhdIaiWW3Nz2JWEmTmrNBsyd3yGFQf//6udvhpNWNUlSKCIPdPksPgHs0S4d0tRk4HW4Pbx6dgrToin0wqYxRHgYdqntJ0686lXF1AGiBpFk7Rdqeqga0x7fq8fUgJ8JFYYyP3pu4KZejjy0qUZsSFayW5J5c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JQoJrb9a; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JQoJrb9a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31172C116B1; Sun, 14 Jul 2024 17:09:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720976943; bh=MxRLc97aWW1jnO5G6Jndd9uzcfVljas1IZvntva/lCs=; h=From:To:Cc:Subject:Date:From; b=JQoJrb9atcNILl3gxuE/+a/h+aqRk7cRcQPuS2x294rEZXNGqaEVwMlBFoyVuc9aM OsJgdz1DgDAmaCfkjGSnxuJXdRE4H6aYI0571cWd5b4EwDDZkPAHQx9leTO0lm2Dqu n6wi4wwXAbKyxno4h52krvbuXMW94oCxaoktW4c0g29ZQ+7JYQ2Xgxf5VyuRD/vZgS Tfa0wDk62afOb5725AoLWw+/eP2tJVU0Wb95D5zkTM2hsn4qjmD6DZGxssJ5R1Tg22 obxBPvZ2DzOMkwplGxd/89KnFq4lLIJN7ekDlZenAYAzm6q56RAb4v6t6CdceTui4J fQKViagwMmGXw== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Arnd Bergmann , Kees Cook , Marco Elver , Masahiro Yamada , Andrew Morton , Kees Cook , linux-hardening@vger.kernel.org Subject: [PATCH] fortify: fix warnings in fortify tests with KASAN Date: Mon, 15 Jul 2024 02:04:32 +0900 Message-ID: <20240714170847.2029108-1-masahiroy@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 When a software KASAN mode is enabled, the fortify tests emit warnings on some architectures. For example, for ARCH=arm, the combination of CONFIG_FORTIFY_SOURCE=y and CONFIG_KASAN=y produces the following warnings: TEST lib/test_fortify/read_overflow-memchr.log warning: unsafe memchr() usage lacked '__read_overflow' warning in lib/test_fortify/read_overflow-memchr.c TEST lib/test_fortify/read_overflow-memchr_inv.log warning: unsafe memchr_inv() usage lacked '__read_overflow' symbol in lib/test_fortify/read_overflow-memchr_inv.c TEST lib/test_fortify/read_overflow-memcmp.log warning: unsafe memcmp() usage lacked '__read_overflow' warning in lib/test_fortify/read_overflow-memcmp.c TEST lib/test_fortify/read_overflow-memscan.log warning: unsafe memscan() usage lacked '__read_overflow' symbol in lib/test_fortify/read_overflow-memscan.c TEST lib/test_fortify/read_overflow2-memcmp.log warning: unsafe memcmp() usage lacked '__read_overflow2' warning in lib/test_fortify/read_overflow2-memcmp.c [ more and more similar warnings... ] Commit 9c2d1328f88a ("kbuild: provide reasonable defaults for tool coverage") removed KASAN flags from non-kernel objects by default. It was an intended behavior because lib/test_fortify/*.c are unit tests that are not linked to the kernel. As it turns out, some architectures require -fsanitize=kernel-(hw)address to define __SANITIZE_ADDRESS__ for the fortify tests. Without __SANITIZE_ADDRESS__ defined, arch/arm/include/asm/string.h defines __NO_FORTIFY, thus excluding . This issue does not occur on x86 thanks to commit 4ec4190be4cf ("kasan, x86: don't rename memintrinsics in uninstrumented files"), but there are still some architectures that define __NO_FORTIFY in such a situation. Set KASAN_SANITIZE=y explicitly to the fortify tests. Fixes: 9c2d1328f88a ("kbuild: provide reasonable defaults for tool coverage") Reported-by: Arnd Bergmann Closes: https://lore.kernel.org/all/0e8dee26-41cc-41ae-9493-10cd1a8e3268@app.fastmail.com/ Signed-off-by: Masahiro Yamada Acked-by: Kees Cook --- Kees Cook said "I'll try to figure this out", but I have not seen a patch so far, so I decided to do this myself. (https://lore.kernel.org/all/202405310908.A5733DF@keescook/) I will send a pull req with this and some other fixes. I need to fix this, as v6.10 will be released soon. lib/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/Makefile b/lib/Makefile index 3b1769045651..30337431d10e 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -426,3 +426,7 @@ $(obj)/$(TEST_FORTIFY_LOG): $(addprefix $(obj)/, $(TEST_FORTIFY_LOGS)) FORCE ifeq ($(CONFIG_FORTIFY_SOURCE),y) $(obj)/string.o: $(obj)/$(TEST_FORTIFY_LOG) endif + +# Some architectures define __NO_FORTIFY if __SANITIZE_ADDRESS__ is undefined. +# Pass CFLAGS_KASAN to avoid warnings. +$(foreach x, $(patsubst %.log,%.o,$(TEST_FORTIFY_LOGS)), $(eval KASAN_SANITIZE_$(x) := y))