android-mainline/FROMLIST-fscrypt-zeroize-fscrypt_info-before-freeing.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Wed, 9 Oct 2019 16:34:17 -0700
Subject: FROMLIST: fscrypt: zeroize fscrypt_info before freeing

memset the struct fscrypt_info to zero before freeing.  This isn't
really needed currently, since there's no secret key directly in the
fscrypt_info.  But there's a decent chance that someone will add such a
field in the future, e.g. in order to use an API that takes a raw key
such as siphash().  So it's good to do this as a hardening measure.

Change-Id: I0fadabcf72d36a0aa786fd5bcc5153c5dbfec8ba
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
Link: https://patchwork.kernel.org/patch/11182405/
---
 fs/crypto/keysetup.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 8eb5a0e762ec..b03b33643e4b 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -327,6 +327,7 @@ static void put_crypt_info(struct fscrypt_info *ci)
 			key_invalidate(key);
 		key_put(key);
 	}
+	memzero_explicit(ci, sizeof(*ci));
 	kmem_cache_free(fscrypt_info_cachep, ci);
 }