[PATCH 3.16 054/204] security/keys: properly zero out sensitive key material in big_key

[Ben Hutchings]

3.16.52-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: "Jason A. Donenfeld" <Jason@xxxxxxxxx>

commit 910801809b2e40a4baedd080ef5d80b4a180e70e upstream.

Error paths forgot to zero out sensitive material, so this patch changes
some kfrees into a kzfrees.

Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Reviewed-by: Eric Biggers <ebiggers3@xxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Kirill Marinushkin <k.marinushkin@xxxxxxxxx>
Cc: security@xxxxxxxxxx
[bwh: Backported to 3.16: there's only one kfree() to change]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 security/keys/big_key.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/security/keys/big_key.c
+++ b/security/keys/big_key.c
@@ -135,7 +135,7 @@ void big_key_destroy(struct key *key)
 		path->mnt = NULL;
 		path->dentry = NULL;
 	} else {
-		kfree(key->payload.data);
+		kzfree(key->payload.data);
 		key->payload.data = NULL;
 	}
 }