[PATCH v7 1/2] security/keys: properly zero out sensitive key material in big_key

[Jason A. Donenfeld]

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

Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com>
Reviewed-by: Eric Biggers <ebigge...@gmail.com>
Cc: David Howells <dhowe...@redhat.com>
Cc: Herbert Xu <herb...@gondor.apana.org.au>
Cc: Kirill Marinushkin <k.marinush...@gmail.com>
Cc: secur...@kernel.org
Cc: sta...@vger.kernel.org
---
 security/keys/big_key.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/security/keys/big_key.c b/security/keys/big_key.c
index 6acb00f6f22c..507d6fb86a4f 100644
--- a/security/keys/big_key.c
+++ b/security/keys/big_key.c
@@ -195,7 +195,7 @@ int big_key_preparse(struct key_preparsed_payload *prep)
                *path = file->f_path;
                path_get(path);
                fput(file);
-               kfree(data);
+               kzfree(data);
        } else {
                /* Just store the data in a buffer */
                void *data = kmalloc(datalen, GFP_KERNEL);
@@ -211,9 +211,9 @@ int big_key_preparse(struct key_preparsed_payload *prep)
 err_fput:
        fput(file);
 err_enckey:
-       kfree(enckey);
+       kzfree(enckey);
 error:
-       kfree(data);
+       kzfree(data);
        return ret;
 }
 
@@ -227,7 +227,7 @@ void big_key_free_preparse(struct key_preparsed_payload 
*prep)
 
                path_put(path);
        }
-       kfree(prep->payload.data[big_key_data]);
+       kzfree(prep->payload.data[big_key_data]);
 }
 
 /*
@@ -259,7 +259,7 @@ void big_key_destroy(struct key *key)
                path->mnt = NULL;
                path->dentry = NULL;
        }
-       kfree(key->payload.data[big_key_data]);
+       kzfree(key->payload.data[big_key_data]);
        key->payload.data[big_key_data] = NULL;
 }
 
@@ -328,7 +328,7 @@ long big_key_read(const struct key *key, char __user 
*buffer, size_t buflen)
 err_fput:
                fput(file);
 error:
-               kfree(data);
+               kzfree(data);
        } else {
                ret = datalen;
                if (copy_to_user(buffer, key->payload.data[big_key_data],
-- 
2.14.1