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.
[[email protected]: fs/crypto/inline_crypt.c needs linux/slab.h]
[[email protected]: fix fs/crypto/inline_crypt.c some more]
Suggested-by: Joe Perches <[email protected]>
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Acked-by: David Howells <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Jarkko Sakkinen <[email protected]>
Cc: James Morris <[email protected]>
Cc: "Serge E. Hallyn" <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: "Jason A . Donenfeld" <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/crypto/drbg.c b/crypto/drbg.c
index 8d80d93..e99fe34 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1218,19 +1218,19 @@ static inline void drbg_dealloc_state(struct drbg_state *drbg)
{
if (!drbg)
return;
- kzfree(drbg->Vbuf);
+ kfree_sensitive(drbg->Vbuf);
drbg->Vbuf = NULL;
drbg->V = NULL;
- kzfree(drbg->Cbuf);
+ kfree_sensitive(drbg->Cbuf);
drbg->Cbuf = NULL;
drbg->C = NULL;
- kzfree(drbg->scratchpadbuf);
+ kfree_sensitive(drbg->scratchpadbuf);
drbg->scratchpadbuf = NULL;
drbg->reseed_ctr = 0;
drbg->d_ops = NULL;
drbg->core = NULL;
if (IS_ENABLED(CONFIG_CRYPTO_FIPS)) {
- kzfree(drbg->prev);
+ kfree_sensitive(drbg->prev);
drbg->prev = NULL;
drbg->fips_primed = false;
}
@@ -1701,7 +1701,7 @@ static int drbg_fini_hash_kernel(struct drbg_state *drbg)
struct sdesc *sdesc = (struct sdesc *)drbg->priv_data;
if (sdesc) {
crypto_free_shash(sdesc->shash.tfm);
- kzfree(sdesc);
+ kfree_sensitive(sdesc);
}
drbg->priv_data = NULL;
return 0;
