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 --- security/keys/big_key.c | 6 +++--- security/keys/dh.c | 14 ++++++------- security/keys/encrypted-keys/encrypted.c | 14 ++++++------- security/keys/trusted-keys/trusted_tpm1.c | 34 +++++++++++++++---------------- security/keys/user_defined.c | 6 +++--- 5 files changed, 37 insertions(+), 37 deletions(-) (limited to 'security/keys') diff --git a/security/keys/big_key.c b/security/keys/big_key.c index dd708e8f13c0..691347dea3c1 100644 --- a/security/keys/big_key.c +++ b/security/keys/big_key.c @@ -138,7 +138,7 @@ int big_key_preparse(struct key_preparsed_payload *prep) err_fput: fput(file); err_enckey: - kzfree(enckey); + kfree_sensitive(enckey); error: memzero_explicit(buf, enclen); kvfree(buf); @@ -155,7 +155,7 @@ void big_key_free_preparse(struct key_preparsed_payload *prep) path_put(path); } - kzfree(prep->payload.data[big_key_data]); + kfree_sensitive(prep->payload.data[big_key_data]); } /* @@ -187,7 +187,7 @@ void big_key_destroy(struct key *key) path->mnt = NULL; path->dentry = NULL; } - kzfree(key->payload.data[big_key_data]); + kfree_sensitive(key->payload.data[big_key_data]); key->payload.data[big_key_data] = NULL; } diff --git a/security/keys/dh.c b/security/keys/dh.c index c4c629bb1c03..1abfa70ed6e1 100644 --- a/security/keys/dh.c +++ b/security/keys/dh.c @@ -58,9 +58,9 @@ error: static void dh_free_data(struct dh *dh) { - kzfree(dh->key); - kzfree(dh->p); - kzfree(dh->g); + kfree_sensitive(dh->key); + kfree_sensitive(dh->p); + kfree_sensitive(dh->g); } struct dh_completion { @@ -126,7 +126,7 @@ static void kdf_dealloc(struct kdf_sdesc *sdesc) if (sdesc->shash.tfm) crypto_free_shash(sdesc->shash.tfm); - kzfree(sdesc); + kfree_sensitive(sdesc); } /* @@ -220,7 +220,7 @@ static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc, ret = -EFAULT; err: - kzfree(outbuf); + kfree_sensitive(outbuf); return ret; } @@ -395,11 +395,11 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params, out6: kpp_request_free(req); out5: - kzfree(outbuf); + kfree_sensitive(outbuf); out4: crypto_free_kpp(tfm); out3: - kzfree(secret); + kfree_sensitive(secret); out2: dh_free_data(&dh_inputs); out1: diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 14cf81d1a30b..deebbf14eeca 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -370,7 +370,7 @@ static int get_derived_key(u8 *derived_key, enum derived_key_type key_type, master_keylen); ret = crypto_shash_tfm_digest(hash_tfm, derived_buf, derived_buf_len, derived_key); - kzfree(derived_buf); + kfree_sensitive(derived_buf); return ret; } @@ -812,13 +812,13 @@ static int encrypted_instantiate(struct key *key, ret = encrypted_init(epayload, key->description, format, master_desc, decrypted_datalen, hex_encoded_iv); if (ret < 0) { - kzfree(epayload); + kfree_sensitive(epayload); goto out; } rcu_assign_keypointer(key, epayload); out: - kzfree(datablob); + kfree_sensitive(datablob); return ret; } @@ -827,7 +827,7 @@ static void encrypted_rcu_free(struct rcu_head *rcu) struct encrypted_key_payload *epayload; epayload = container_of(rcu, struct encrypted_key_payload, rcu); - kzfree(epayload); + kfree_sensitive(epayload); } /* @@ -885,7 +885,7 @@ static int encrypted_update(struct key *key, struct key_preparsed_payload *prep) rcu_assign_keypointer(key, new_epayload); call_rcu(&epayload->rcu, encrypted_rcu_free); out: - kzfree(buf); + kfree_sensitive(buf); return ret; } @@ -946,7 +946,7 @@ static long encrypted_read(const struct key *key, char *buffer, memzero_explicit(derived_key, sizeof(derived_key)); memcpy(buffer, ascii_buf, asciiblob_len); - kzfree(ascii_buf); + kfree_sensitive(ascii_buf); return asciiblob_len; out: @@ -961,7 +961,7 @@ out: */ static void encrypted_destroy(struct key *key) { - kzfree(key->payload.data[0]); + kfree_sensitive(key->payload.data[0]); } struct key_type key_type_encrypted = { diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 8001ab07e63b..b9fe02e5f84f 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -68,7 +68,7 @@ static int TSS_sha1(const unsigned char *data, unsigned int datalen, } ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest); - kzfree(sdesc); + kfree_sensitive(sdesc); return ret; } @@ -112,7 +112,7 @@ static int TSS_rawhmac(unsigned char *digest, const unsigned char *key, if (!ret) ret = crypto_shash_final(&sdesc->shash, digest); out: - kzfree(sdesc); + kfree_sensitive(sdesc); return ret; } @@ -166,7 +166,7 @@ int TSS_authhmac(unsigned char *digest, const unsigned char *key, paramdigest, TPM_NONCE_SIZE, h1, TPM_NONCE_SIZE, h2, 1, &c, 0, 0); out: - kzfree(sdesc); + kfree_sensitive(sdesc); return ret; } EXPORT_SYMBOL_GPL(TSS_authhmac); @@ -251,7 +251,7 @@ int TSS_checkhmac1(unsigned char *buffer, if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) ret = -EINVAL; out: - kzfree(sdesc); + kfree_sensitive(sdesc); return ret; } EXPORT_SYMBOL_GPL(TSS_checkhmac1); @@ -353,7 +353,7 @@ static int TSS_checkhmac2(unsigned char *buffer, if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) ret = -EINVAL; out: - kzfree(sdesc); + kfree_sensitive(sdesc); return ret; } @@ -563,7 +563,7 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, *bloblen = storedsize; } out: - kzfree(td); + kfree_sensitive(td); return ret; } @@ -1031,12 +1031,12 @@ static int trusted_instantiate(struct key *key, if (!ret && options->pcrlock) ret = pcrlock(options->pcrlock); out: - kzfree(datablob); - kzfree(options); + kfree_sensitive(datablob); + kfree_sensitive(options); if (!ret) rcu_assign_keypointer(key, payload); else - kzfree(payload); + kfree_sensitive(payload); return ret; } @@ -1045,7 +1045,7 @@ static void trusted_rcu_free(struct rcu_head *rcu) struct trusted_key_payload *p; p = container_of(rcu, struct trusted_key_payload, rcu); - kzfree(p); + kfree_sensitive(p); } /* @@ -1087,13 +1087,13 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep) ret = datablob_parse(datablob, new_p, new_o); if (ret != Opt_update) { ret = -EINVAL; - kzfree(new_p); + kfree_sensitive(new_p); goto out; } if (!new_o->keyhandle) { ret = -EINVAL; - kzfree(new_p); + kfree_sensitive(new_p); goto out; } @@ -1107,22 +1107,22 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep) ret = key_seal(new_p, new_o); if (ret < 0) { pr_info("trusted_key: key_seal failed (%d)\n", ret); - kzfree(new_p); + kfree_sensitive(new_p); goto out; } if (new_o->pcrlock) { ret = pcrlock(new_o->pcrlock); if (ret < 0) { pr_info("trusted_key: pcrlock failed (%d)\n", ret); - kzfree(new_p); + kfree_sensitive(new_p); goto out; } } rcu_assign_keypointer(key, new_p); call_rcu(&p->rcu, trusted_rcu_free); out: - kzfree(datablob); - kzfree(new_o); + kfree_sensitive(datablob); + kfree_sensitive(new_o); return ret; } @@ -1154,7 +1154,7 @@ static long trusted_read(const struct key *key, char *buffer, */ static void trusted_destroy(struct key *key) { - kzfree(key->payload.data[0]); + kfree_sensitive(key->payload.data[0]); } struct key_type key_type_trusted = { diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 07d4287e9084..749e2a4dcb13 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -82,7 +82,7 @@ EXPORT_SYMBOL_GPL(user_preparse); */ void user_free_preparse(struct key_preparsed_payload *prep) { - kzfree(prep->payload.data[0]); + kfree_sensitive(prep->payload.data[0]); } EXPORT_SYMBOL_GPL(user_free_preparse); @@ -91,7 +91,7 @@ static void user_free_payload_rcu(struct rcu_head *head) struct user_key_payload *payload; payload = container_of(head, struct user_key_payload, rcu); - kzfree(payload); + kfree_sensitive(payload); } /* @@ -147,7 +147,7 @@ void user_destroy(struct key *key) { struct user_key_payload *upayload = key->payload.data[0]; - kzfree(upayload); + kfree_sensitive(upayload); } EXPORT_SYMBOL_GPL(user_destroy); -- cgit