From: Stefan Rompf <stefan@loplof.de>

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>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/md/dm-crypt.c |    5 +++++
 1 files changed, 5 insertions(+)

diff -puN drivers/md/dm-crypt.c~dm-crypt-zero-key-before-freeing-it drivers/md/dm-crypt.c
--- 25/drivers/md/dm-crypt.c~dm-crypt-zero-key-before-freeing-it	Wed Jan  4 15:03:01 2006
+++ 25-akpm/drivers/md/dm-crypt.c	Wed Jan  4 15:03:01 2006
@@ -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 *
 		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);
 }
 
_