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/user_defined.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'security/keys/user_defined.c') diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 07d4287e9084..749e2a4dcb13 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -82,7 +82,7 @@ EXPORT_SYMBOL_GPL(user_preparse); */ void user_free_preparse(struct key_preparsed_payload *prep) { - kzfree(prep->payload.data[0]); + kfree_sensitive(prep->payload.data[0]); } EXPORT_SYMBOL_GPL(user_free_preparse); @@ -91,7 +91,7 @@ static void user_free_payload_rcu(struct rcu_head *head) struct user_key_payload *payload; payload = container_of(head, struct user_key_payload, rcu); - kzfree(payload); + kfree_sensitive(payload); } /* @@ -147,7 +147,7 @@ void user_destroy(struct key *key) { struct user_key_payload *upayload = key->payload.data[0]; - kzfree(upayload); + kfree_sensitive(upayload); } EXPORT_SYMBOL_GPL(user_destroy); -- cgit v1.2.3