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 <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Waiman Long
2020-08-06 23:18:13 -07:00
committed by Linus Torvalds
parent 57c720d414
commit 453431a549
114 changed files with 323 additions and 320 deletions

View File

@@ -167,7 +167,7 @@ static int virtio_crypto_alg_skcipher_init_session(
num_in, vcrypto, GFP_ATOMIC);
if (err < 0) {
spin_unlock(&vcrypto->ctrl_lock);
kzfree(cipher_key);
kfree_sensitive(cipher_key);
return err;
}
virtqueue_kick(vcrypto->ctrl_vq);
@@ -184,7 +184,7 @@ static int virtio_crypto_alg_skcipher_init_session(
spin_unlock(&vcrypto->ctrl_lock);
pr_err("virtio_crypto: Create session failed status: %u\n",
le32_to_cpu(vcrypto->input.status));
kzfree(cipher_key);
kfree_sensitive(cipher_key);
return -EINVAL;
}
@@ -197,7 +197,7 @@ static int virtio_crypto_alg_skcipher_init_session(
spin_unlock(&vcrypto->ctrl_lock);
kzfree(cipher_key);
kfree_sensitive(cipher_key);
return 0;
}
@@ -472,9 +472,9 @@ __virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
return 0;
free_iv:
kzfree(iv);
kfree_sensitive(iv);
free:
kzfree(req_data);
kfree_sensitive(req_data);
kfree(sgs);
return err;
}
@@ -583,7 +583,7 @@ static void virtio_crypto_skcipher_finalize_req(
scatterwalk_map_and_copy(req->iv, req->dst,
req->cryptlen - AES_BLOCK_SIZE,
AES_BLOCK_SIZE, 0);
kzfree(vc_sym_req->iv);
kfree_sensitive(vc_sym_req->iv);
virtcrypto_clear_request(&vc_sym_req->base);
crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,