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>
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 433227f..bf4bef1 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -753,9 +753,9 @@ static void smp_chan_destroy(struct l2cap_conn *conn)
complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
mgmt_smp_complete(hcon, complete);
- kzfree(smp->csrk);
- kzfree(smp->slave_csrk);
- kzfree(smp->link_key);
+ kfree_sensitive(smp->csrk);
+ kfree_sensitive(smp->slave_csrk);
+ kfree_sensitive(smp->link_key);
crypto_free_shash(smp->tfm_cmac);
crypto_free_kpp(smp->tfm_ecdh);
@@ -789,7 +789,7 @@ static void smp_chan_destroy(struct l2cap_conn *conn)
}
chan->data = NULL;
- kzfree(smp);
+ kfree_sensitive(smp);
hci_conn_drop(hcon);
}
@@ -1156,7 +1156,7 @@ static void sc_generate_link_key(struct smp_chan *smp)
const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 };
if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) {
- kzfree(smp->link_key);
+ kfree_sensitive(smp->link_key);
smp->link_key = NULL;
return;
}
@@ -1165,14 +1165,14 @@ static void sc_generate_link_key(struct smp_chan *smp)
const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
- kzfree(smp->link_key);
+ kfree_sensitive(smp->link_key);
smp->link_key = NULL;
return;
}
}
if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
- kzfree(smp->link_key);
+ kfree_sensitive(smp->link_key);
smp->link_key = NULL;
return;
}
@@ -1407,7 +1407,7 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
free_shash:
crypto_free_shash(smp->tfm_cmac);
zfree_smp:
- kzfree(smp);
+ kfree_sensitive(smp);
return NULL;
}
@@ -3278,7 +3278,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0);
if (IS_ERR(tfm_cmac)) {
BT_ERR("Unable to create CMAC crypto context");
- kzfree(smp);
+ kfree_sensitive(smp);
return ERR_CAST(tfm_cmac);
}
@@ -3286,7 +3286,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
if (IS_ERR(tfm_ecdh)) {
BT_ERR("Unable to create ECDH crypto context");
crypto_free_shash(tfm_cmac);
- kzfree(smp);
+ kfree_sensitive(smp);
return ERR_CAST(tfm_ecdh);
}
@@ -3300,7 +3300,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid)
if (smp) {
crypto_free_shash(smp->tfm_cmac);
crypto_free_kpp(smp->tfm_ecdh);
- kzfree(smp);
+ kfree_sensitive(smp);
}
return ERR_PTR(-ENOMEM);
}
@@ -3347,7 +3347,7 @@ static void smp_del_chan(struct l2cap_chan *chan)
chan->data = NULL;
crypto_free_shash(smp->tfm_cmac);
crypto_free_kpp(smp->tfm_ecdh);
- kzfree(smp);
+ kfree_sensitive(smp);
}
l2cap_chan_put(chan);
