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 --- drivers/md/dm-crypt.c | 32 ++++++++++++++++---------------- drivers/md/dm-integrity.c | 6 +++--- 2 files changed, 19 insertions(+), 19 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index b437a14c4942..37dcc52cf21d 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -407,7 +407,7 @@ static void crypt_iv_lmk_dtr(struct crypt_config *cc) crypto_free_shash(lmk->hash_tfm); lmk->hash_tfm = NULL; - kzfree(lmk->seed); + kfree_sensitive(lmk->seed); lmk->seed = NULL; } @@ -558,9 +558,9 @@ static void crypt_iv_tcw_dtr(struct crypt_config *cc) { struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; - kzfree(tcw->iv_seed); + kfree_sensitive(tcw->iv_seed); tcw->iv_seed = NULL; - kzfree(tcw->whitening); + kfree_sensitive(tcw->whitening); tcw->whitening = NULL; if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) @@ -994,8 +994,8 @@ static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *d kunmap_atomic(data); out: - kzfree(ks); - kzfree(es); + kfree_sensitive(ks); + kfree_sensitive(es); skcipher_request_free(req); return r; } @@ -2294,7 +2294,7 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string key = request_key(type, key_desc + 1, NULL); if (IS_ERR(key)) { - kzfree(new_key_string); + kfree_sensitive(new_key_string); return PTR_ERR(key); } @@ -2304,7 +2304,7 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string if (ret < 0) { up_read(&key->sem); key_put(key); - kzfree(new_key_string); + kfree_sensitive(new_key_string); return ret; } @@ -2318,10 +2318,10 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string if (!ret) { set_bit(DM_CRYPT_KEY_VALID, &cc->flags); - kzfree(cc->key_string); + kfree_sensitive(cc->key_string); cc->key_string = new_key_string; } else - kzfree(new_key_string); + kfree_sensitive(new_key_string); return ret; } @@ -2382,7 +2382,7 @@ static int crypt_set_key(struct crypt_config *cc, char *key) clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); /* wipe references to any kernel keyring key */ - kzfree(cc->key_string); + kfree_sensitive(cc->key_string); cc->key_string = NULL; /* Decode key from its hex representation. */ @@ -2414,7 +2414,7 @@ static int crypt_wipe_key(struct crypt_config *cc) return r; } - kzfree(cc->key_string); + kfree_sensitive(cc->key_string); cc->key_string = NULL; r = crypt_setkey(cc); memset(&cc->key, 0, cc->key_size * sizeof(u8)); @@ -2493,15 +2493,15 @@ static void crypt_dtr(struct dm_target *ti) if (cc->dev) dm_put_device(ti, cc->dev); - kzfree(cc->cipher_string); - kzfree(cc->key_string); - kzfree(cc->cipher_auth); - kzfree(cc->authenc_key); + kfree_sensitive(cc->cipher_string); + kfree_sensitive(cc->key_string); + kfree_sensitive(cc->cipher_auth); + kfree_sensitive(cc->authenc_key); mutex_destroy(&cc->bio_alloc_lock); /* Must zero key material before freeing */ - kzfree(cc); + kfree_sensitive(cc); spin_lock(&dm_crypt_clients_lock); WARN_ON(!dm_crypt_clients_n); diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 5da3eb661e50..8c8d940e532e 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -3405,8 +3405,8 @@ static struct scatterlist **dm_integrity_alloc_journal_scatterlist(struct dm_int static void free_alg(struct alg_spec *a) { - kzfree(a->alg_string); - kzfree(a->key); + kfree_sensitive(a->alg_string); + kfree_sensitive(a->key); memset(a, 0, sizeof *a); } @@ -4337,7 +4337,7 @@ static void dm_integrity_dtr(struct dm_target *ti) for (i = 0; i < ic->journal_sections; i++) { struct skcipher_request *req = ic->sk_requests[i]; if (req) { - kzfree(req->iv); + kfree_sensitive(req->iv); skcipher_request_free(req); } } -- cgit v1.2.3