From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:53270 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725440AbfAIGM5 (ORCPT ); Wed, 9 Jan 2019 01:12:57 -0500 From: Eric Biggers To: linux-crypto@vger.kernel.org, Herbert Xu Cc: Gilad Ben-Yossef Subject: [PATCH] crypto: sm3 - fix undefined shift by >= width of value Date: Tue, 8 Jan 2019 22:12:41 -0800 Message-Id: <20190109061241.6943-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-crypto-owner@vger.kernel.org List-ID: From: Eric Biggers sm3_compress() calls rol32() with shift >= 32, which causes undefined behavior. This is easily detected by enabling CONFIG_UBSAN. Explicitly AND with 31 to make the behavior well defined. Fixes: 4f0fc1600edb ("crypto: sm3 - add OSCCA SM3 secure hash") Cc: # v4.15+ Cc: Gilad Ben-Yossef Signed-off-by: Eric Biggers --- crypto/sm3_generic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crypto/sm3_generic.c b/crypto/sm3_generic.c index 9a5c60f08aad8..c0cf87ae7ef6d 100644 --- a/crypto/sm3_generic.c +++ b/crypto/sm3_generic.c @@ -100,7 +100,7 @@ static void sm3_compress(u32 *w, u32 *wt, u32 *m) for (i = 0; i <= 63; i++) { - ss1 = rol32((rol32(a, 12) + e + rol32(t(i), i)), 7); + ss1 = rol32((rol32(a, 12) + e + rol32(t(i), i & 31)), 7); ss2 = ss1 ^ rol32(a, 12); -- 2.20.1