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/dh.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'security/keys/dh.c') diff --git a/security/keys/dh.c b/security/keys/dh.c index c4c629bb1c03..1abfa70ed6e1 100644 --- a/security/keys/dh.c +++ b/security/keys/dh.c @@ -58,9 +58,9 @@ error: static void dh_free_data(struct dh *dh) { - kzfree(dh->key); - kzfree(dh->p); - kzfree(dh->g); + kfree_sensitive(dh->key); + kfree_sensitive(dh->p); + kfree_sensitive(dh->g); } struct dh_completion { @@ -126,7 +126,7 @@ static void kdf_dealloc(struct kdf_sdesc *sdesc) if (sdesc->shash.tfm) crypto_free_shash(sdesc->shash.tfm); - kzfree(sdesc); + kfree_sensitive(sdesc); } /* @@ -220,7 +220,7 @@ static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc, ret = -EFAULT; err: - kzfree(outbuf); + kfree_sensitive(outbuf); return ret; } @@ -395,11 +395,11 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params, out6: kpp_request_free(req); out5: - kzfree(outbuf); + kfree_sensitive(outbuf); out4: crypto_free_kpp(tfm); out3: - kzfree(secret); + kfree_sensitive(secret); out2: dh_free_data(&dh_inputs); out1: -- cgit v1.2.3-59-g8ed1b