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 --- crypto/drbg.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'crypto/drbg.c') diff --git a/crypto/drbg.c b/crypto/drbg.c index 8d80d93cab97..e99fe34cfa00 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; -- cgit v1.2.3