From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933259AbbAFVhT (ORCPT ); Tue, 6 Jan 2015 16:37:19 -0500 Received: from khitomer.mortis.eu ([185.27.175.75]:29899 "EHLO khitomer.mortis.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932931AbbAFVhQ (ORCPT ); Tue, 6 Jan 2015 16:37:16 -0500 From: Giel van Schijndel To: linux-kernel@vger.kernel.org Cc: Herbert Xu , Giel van Schijndel , Steve French , linux-cifs@vger.kernel.org (open list:COMMON INTERNET F...), samba-technical@lists.samba.org (moderated list:COMMON INTERNET F...) Subject: [PATCH RESEND] cifs: use memzero_explicit to clear stack buffer Date: Tue, 6 Jan 2015 22:37:00 +0100 Message-Id: <1420580220-6276-1-git-send-email-me@mortis.eu> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1420394744-20268-1-git-send-email-me@mortis.eu> References: <1420394744-20268-1-git-send-email-me@mortis.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When leaving a function use memzero_explicit instead of memset(0) to clear stack allocated buffers. memset(0) may be optimized away. This particular buffer is highly likely to contain sensitive data which we shouldn't leak (it's named 'passwd' after all). Signed-off-by: Giel van Schijndel Reported-at: http://www.viva64.com/en/b/0299/ Reported-by: Andrey Karpov Reported-by: Svyatoslav Razmyslov --- fs/cifs/smbencrypt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/cifs/smbencrypt.c b/fs/cifs/smbencrypt.c index 6c15663..a4232ec 100644 --- a/fs/cifs/smbencrypt.c +++ b/fs/cifs/smbencrypt.c @@ -221,7 +221,7 @@ E_md4hash(const unsigned char *passwd, unsigned char *p16, } rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16)); - memset(wpwd, 0, 129 * sizeof(__le16)); + memzero_explicit(wpwd, sizeof(wpwd)); return rc; } -- 2.1.4