From: Milan Broz <gmazyland@gmail.com>
Date: Sat, 22 Nov 2014 08:36:04 +0000 (+0100)
Subject: dm crypt: use memzero_explicit for on-stack buffer
X-Git-Tag: v3.17.8~54
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=64ce4fff66322b496bbcffa9505a49056cd84150;p=thirdparty%2Fkernel%2Fstable.git

dm crypt: use memzero_explicit for on-stack buffer

commit 1a71d6ffe18c0d0f03fc8531949cc8ed41d702ee upstream.

Use memzero_explicit to cleanup sensitive data allocated on stack
to prevent the compiler from optimizing and removing memset() calls.

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index cd15e08012284..ce11a90a33c3e 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -711,7 +711,7 @@ static int crypt_iv_tcw_whitening(struct crypt_config *cc,
 	for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
 		crypto_xor(data + i * 8, buf, 8);
 out:
-	memset(buf, 0, sizeof(buf));
+	memzero_explicit(buf, sizeof(buf));
 	return r;
 }