From: Arnd Bergmann <arnd@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
Nathan Chancellor <natechancellor@gmail.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Marco Elver <elver@google.com>,
George Popescu <georgepope@android.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: [PATCH] ubsan: disable unsigned-integer-overflow sanitizer with clang
Date: Wed, 30 Dec 2020 16:47:35 +0100 [thread overview]
Message-ID: <20201230154749.746641-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
Building ubsan kernels even for compile-testing introduced these
warnings in my randconfig environment:
crypto/blake2b_generic.c:98:13: error: stack frame size of 9636 bytes in function 'blake2b_compress' [-Werror,-Wframe-larger-than=]
static void blake2b_compress(struct blake2b_state *S,
crypto/sha512_generic.c:151:13: error: stack frame size of 1292 bytes in function 'sha512_generic_block_fn' [-Werror,-Wframe-larger-than=]
static void sha512_generic_block_fn(struct sha512_state *sst, u8 const *src,
lib/crypto/curve25519-fiat32.c:312:22: error: stack frame size of 2180 bytes in function 'fe_mul_impl' [-Werror,-Wframe-larger-than=]
static noinline void fe_mul_impl(u32 out[10], const u32 in1[10], const u32 in2[10])
lib/crypto/curve25519-fiat32.c:444:22: error: stack frame size of 1588 bytes in function 'fe_sqr_impl' [-Werror,-Wframe-larger-than=]
static noinline void fe_sqr_impl(u32 out[10], const u32 in1[10])
Further testing showed that this is caused by
-fsanitize=unsigned-integer-overflow.
The one in blake2b immediately overflows the 8KB stack area on 32-bit
architectures, so better ensure this never happens by making this
option gcc-only.
Fixes: d0a3ac549f38 ("ubsan: enable for all*config builds")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
lib/Kconfig.ubsan | 2 ++
1 file changed, 2 insertions(+)
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 8b635fd75fe4..e23873282ba7 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -122,6 +122,8 @@ config UBSAN_SIGNED_OVERFLOW
config UBSAN_UNSIGNED_OVERFLOW
bool "Perform checking for unsigned arithmetic overflow"
+ # clang hugely expands stack usage with -fsanitize=object-size
+ depends on !CC_IS_CLANG
depends on $(cc-option,-fsanitize=unsigned-integer-overflow)
help
This option enables -fsanitize=unsigned-integer-overflow which checks
--
2.29.2
next reply other threads:[~2020-12-30 15:48 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-30 15:47 Arnd Bergmann [this message]
2020-12-30 16:13 ` [PATCH] ubsan: disable unsigned-integer-overflow sanitizer with clang Marco Elver
2021-01-04 22:33 ` Nathan Chancellor
2021-01-04 23:33 ` Andrew Morton
2021-01-04 23:34 ` Nathan Chancellor
2021-01-05 9:25 ` Arnd Bergmann
2021-01-06 9:12 ` Arnd Bergmann
2021-01-06 21:38 ` Nathan Chancellor
2021-01-06 22:06 ` Arnd Bergmann
2021-01-07 3:34 ` Nathan Chancellor
2021-01-06 21:57 ` Kees Cook
2021-01-06 22:12 ` Arnd Bergmann
2021-01-06 23:17 ` Kees Cook
2021-01-06 23:40 ` Arnd Bergmann
2021-01-07 16:09 ` Arnd Bergmann
2021-01-07 17:22 ` Kees Cook
2021-01-07 18:15 ` Nathan Chancellor
2021-01-07 20:41 ` Arnd Bergmann
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