From 453431a54934d917153c65211b2dabf45562ca88 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Thu, 6 Aug 2020 23:18:13 -0700 Subject: mm, treewide: rename kzfree() to kfree_sensitive() As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches Signed-off-by: Waiman Long Signed-off-by: Andrew Morton Acked-by: David Howells Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Jarkko Sakkinen Cc: James Morris Cc: "Serge E. Hallyn" Cc: Joe Perches Cc: Matthew Wilcox Cc: David Rientjes Cc: Dan Carpenter Cc: "Jason A . Donenfeld" Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds --- security/keys/encrypted-keys/encrypted.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'security/keys/encrypted-keys/encrypted.c') diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 14cf81d1a30b..deebbf14eeca 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -370,7 +370,7 @@ static int get_derived_key(u8 *derived_key, enum derived_key_type key_type, master_keylen); ret = crypto_shash_tfm_digest(hash_tfm, derived_buf, derived_buf_len, derived_key); - kzfree(derived_buf); + kfree_sensitive(derived_buf); return ret; } @@ -812,13 +812,13 @@ static int encrypted_instantiate(struct key *key, ret = encrypted_init(epayload, key->description, format, master_desc, decrypted_datalen, hex_encoded_iv); if (ret < 0) { - kzfree(epayload); + kfree_sensitive(epayload); goto out; } rcu_assign_keypointer(key, epayload); out: - kzfree(datablob); + kfree_sensitive(datablob); return ret; } @@ -827,7 +827,7 @@ static void encrypted_rcu_free(struct rcu_head *rcu) struct encrypted_key_payload *epayload; epayload = container_of(rcu, struct encrypted_key_payload, rcu); - kzfree(epayload); + kfree_sensitive(epayload); } /* @@ -885,7 +885,7 @@ static int encrypted_update(struct key *key, struct key_preparsed_payload *prep) rcu_assign_keypointer(key, new_epayload); call_rcu(&epayload->rcu, encrypted_rcu_free); out: - kzfree(buf); + kfree_sensitive(buf); return ret; } @@ -946,7 +946,7 @@ static long encrypted_read(const struct key *key, char *buffer, memzero_explicit(derived_key, sizeof(derived_key)); memcpy(buffer, ascii_buf, asciiblob_len); - kzfree(ascii_buf); + kfree_sensitive(ascii_buf); return asciiblob_len; out: @@ -961,7 +961,7 @@ out: */ static void encrypted_destroy(struct key *key) { - kzfree(key->payload.data[0]); + kfree_sensitive(key->payload.data[0]); } struct key_type key_type_encrypted = { -- cgit v1.2.3