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 --- fs/ecryptfs/keystore.c | 4 ++-- fs/ecryptfs/messaging.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index af3eb02bbca1..f6a17d259db7 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -838,7 +838,7 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, out_release_free_unlock: crypto_free_shash(s->hash_tfm); out_free_unlock: - kzfree(s->block_aligned_filename); + kfree_sensitive(s->block_aligned_filename); out_unlock: mutex_unlock(s->tfm_mutex); out: @@ -847,7 +847,7 @@ out: key_put(auth_tok_key); } skcipher_request_free(s->skcipher_req); - kzfree(s->hash_desc); + kfree_sensitive(s->hash_desc); kfree(s); return rc; } diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c index 8646ba76def3..c0dfd9647627 100644 --- a/fs/ecryptfs/messaging.c +++ b/fs/ecryptfs/messaging.c @@ -175,7 +175,7 @@ int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon) } hlist_del(&daemon->euid_chain); mutex_unlock(&daemon->mux); - kzfree(daemon); + kfree_sensitive(daemon); out: return rc; } -- cgit v1.2.3