From: Stefan Rompf <stefan@loplof.de>
Date: Fri, 6 Jan 2006 17:21:39 +0000 (-0800)
Subject: [PATCH] dm-crypt: zero key before freeing it
X-Git-Tag: v2.6.15.4~23
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9532d48ec7403bcab71518f1116eb9c7746053c;p=thirdparty%2Fkernel%2Fstable.git

[PATCH] dm-crypt: zero key before freeing it

Zap the memory before freeing it so we don't leave crypto information
around in memory.

Signed-off-by: Stefan Rompf <stefan@loplof.de>
Acked-by: Clemens Fruhwirth <clemens@endorphin.org>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index cf6631056683b..a601a427885cb 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -690,6 +690,8 @@ bad3:
 bad2:
 	crypto_free_tfm(tfm);
 bad1:
+	/* Must zero key material before freeing */
+	memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
 	kfree(cc);
 	return -EINVAL;
 }
@@ -706,6 +708,9 @@ static void crypt_dtr(struct dm_target *ti)
 		cc->iv_gen_ops->dtr(cc);
 	crypto_free_tfm(cc->tfm);
 	dm_put_device(ti, cc->dev);
+
+	/* Must zero key material before freeing */
+	memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
 	kfree(cc);
 }