[Patch 2.6] dm-crypt: Zero key material before free to avoid information leak

[Stefan Rompf <stefan@loplof.de>]

Am Mittwoch 04 Januar 2006 22:15 schrieb Greg KH:

> Yes, Stefan, care to redo this with an updated changelog command?


dm-crypt should clear struct crypt_config before freeing it to
avoid information leak f.e. to a swsusp image.

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

--- linux-2.6.15/drivers/md/dm-crypt.c.orig	2006-01-04 01:01:16.000000000 +0100
+++ linux-2.6.15/drivers/md/dm-crypt.c	2006-01-04 22:35:13.000000000 +0100
@@ -690,6 +690,8 @@
 bad2:
 	crypto_free_tfm(tfm);
 bad1:
+	/* Zero key material before free to avoid information leak */
+	memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
 	kfree(cc);
 	return -EINVAL;
 }
@@ -706,6 +708,9 @@
 		cc->iv_gen_ops->dtr(cc);
 	crypto_free_tfm(cc->tfm);
 	dm_put_device(ti, cc->dev);
+
+	/* Zero key material before free to avoid information leak */
+	memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
 	kfree(cc);
 }