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From: Stefan Rompf <stefan@loplof.de>
To: Andrew Morton <akpm@osdl.org>
Cc: Clemens Fruhwirth <clemens@endorphin.org>,
	linux-kernel@vger.kernel.org, stable@kernel.org
Subject: [Patch 2.6] dm-crypt: zero key before freeing it
Date: Wed, 4 Jan 2006 21:08:04 +0100	[thread overview]
Message-ID: <200601042108.04544.stefan@loplof.de> (raw)

Hi Andrew,

dm-crypt does not clear struct crypt_config before freeing it. Thus, 
information on the key could leak f.e. to a swsusp image even after the 
encrypted device has been removed. The attached patch against 2.6.14 / 2.6.15 
fixes it.

Signed-off-by: Stefan Rompf <stefan@loplof.de>
Acked-by: Clemens Fruhwirth <clemens@endorphin.org>

--- linux-2.6.14.4/drivers/md/dm-crypt.c.old	2005-12-16 18:27:05.000000000 +0100
+++ linux-2.6.14.4/drivers/md/dm-crypt.c	2005-12-28 12:49:13.000000000 +0100
@@ -694,6 +694,7 @@ bad3:
 bad2:
 	crypto_free_tfm(tfm);
 bad1:
+	memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
 	kfree(cc);
 	return -EINVAL;
 }
@@ -710,6 +711,7 @@ static void crypt_dtr(struct dm_target *
 		cc->iv_gen_ops->dtr(cc);
 	crypto_free_tfm(cc->tfm);
 	dm_put_device(ti, cc->dev);
+	memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
 	kfree(cc);
 }
 


             reply	other threads:[~2006-01-04 20:08 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-01-04 20:08 Stefan Rompf [this message]
2006-01-04 20:09 ` [Patch 2.6] dm-crypt: zero key before freeing it Arjan van de Ven
2006-01-04 20:26   ` Stefan Rompf
2006-01-04 20:28     ` Randy.Dunlap
2006-01-04 20:41       ` Jörn Engel
2006-01-04 20:43         ` Randy.Dunlap
2006-01-04 21:15           ` [stable] " Greg KH
2006-01-04 21:44             ` [Patch 2.6] dm-crypt: Zero key material before free to avoid information leak Stefan Rompf
2006-01-24  4:49 ` [Patch 2.6] dm-crypt: zero key before freeing it Neil Brown
2006-01-24 21:29   ` Stefan Rompf
2006-01-24 21:44     ` Neil Brown
2006-01-24 23:03 ` Phillip Susi

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