linux-kernel - [PATCH 4/8] cifs: replace memset by memzero

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1417366774-32412-5-git-send-email-Julia.Lawall@lip6.fr>
Date:	Sun, 30 Nov 2014 17:59:30 +0100
From:	Julia Lawall <Julia.Lawall@...6.fr>
To:	Steve French <sfrench@...ba.org>
Cc:	dborkman@...hat.com, herbert@...dor.apana.org.au,
	kernel-janitors@...r.kernel.org, linux-cifs@...r.kernel.org,
	samba-technical@...ts.samba.org, linux-kernel@...r.kernel.org,
	Julia Lawall <julia@...u.dk>
Subject: [PATCH 4/8] cifs: replace memset by memzero_explicit

From: Julia Lawall <julia@...u.dk>

Memset on a local variable may be removed when it is called just before the
variable goes out of scope.  Using memzero_explicit defeats this
optimization.  A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
type T;
@@

{
... when any
T x[...];
... when any
    when exists
- memset
+ memzero_explicit
  (x,
-0,
  ...)
... when != x
    when strict
}
// </smpl>

This change was suggested by Daniel Borkmann <dborkman@...hat.com>

Signed-off-by: Julia Lawall <julia@...u.dk>

---
Daniel Borkmann suggested that these patches could go through Herbert Xu's
cryptodev tree.

 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..6512c19 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, 129 * sizeof(__le16));
 
 	return rc;
 }

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/