From: Waiman Long <longman@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>,
David Howells <dhowells@redhat.com>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Joe Perches <joe@perches.com>,
Matthew Wilcox <willy@infradead.org>,
David Rientjes <rientjes@google.com>,
Corentin Labbe <clabbe.montjoie@gmail.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
Chen-Yu Tsai <wens@csie.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
keyrings@vger.kernel.org, linux-crypto@vger.kernel.org,
Waiman Long <longman@redhat.com>,
linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 2/3] crypto: Remove unnecessary memzero_explicit()
Date: Tue, 14 Apr 2020 16:02:14 -0400 [thread overview]
Message-ID: <20200414200214.1873-1-longman@redhat.com> (raw)
In-Reply-To: <20200413211550.8307-1-longman@redhat.com>
Since kfree_sensitive() will do an implicit memzero_explicit(),
there is no need to call memzero_explicit() before it. Eliminate those
memzero_explicit() and simplify the call sites. For better correctness,
keylen is cleared if key memory allocation fails.
Signed-off-by: Waiman Long <longman@redhat.com>
---
.../allwinner/sun8i-ce/sun8i-ce-cipher.c | 23 +++++++-----------
.../allwinner/sun8i-ss/sun8i-ss-cipher.c | 24 +++++++------------
drivers/crypto/amlogic/amlogic-gxl-cipher.c | 14 ++++-------
drivers/crypto/inside-secure/safexcel_hash.c | 3 +--
4 files changed, 24 insertions(+), 40 deletions(-)
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
index aa4e8fdc2b32..a2bac10d2876 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
@@ -366,10 +366,7 @@ void sun8i_ce_cipher_exit(struct crypto_tfm *tfm)
{
struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
crypto_free_sync_skcipher(op->fallback_tfm);
pm_runtime_put_sync_suspend(op->ce->dev);
}
@@ -391,14 +388,13 @@ int sun8i_ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
dev_dbg(ce->dev, "ERROR: Invalid keylen %u\n", keylen);
return -EINVAL;
}
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
op->keylen = keylen;
op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
- if (!op->key)
+ if (unlikely(!op->key)) {
+ op->keylen = 0;
return -ENOMEM;
+ }
crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
@@ -416,14 +412,13 @@ int sun8i_ce_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
if (err)
return err;
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
op->keylen = keylen;
op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
- if (!op->key)
+ if (unlikely(!op->key)) {
+ op->keylen = 0;
return -ENOMEM;
+ }
crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
index 5246ef4f5430..a24d567a6c36 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
@@ -249,7 +249,6 @@ static int sun8i_ss_cipher(struct skcipher_request *areq)
offset = areq->cryptlen - ivsize;
if (rctx->op_dir & SS_DECRYPTION) {
memcpy(areq->iv, backup_iv, ivsize);
- memzero_explicit(backup_iv, ivsize);
kfree_sensitive(backup_iv);
} else {
scatterwalk_map_and_copy(areq->iv, areq->dst, offset,
@@ -367,10 +366,7 @@ void sun8i_ss_cipher_exit(struct crypto_tfm *tfm)
{
struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
crypto_free_sync_skcipher(op->fallback_tfm);
pm_runtime_put_sync(op->ss->dev);
}
@@ -392,14 +388,13 @@ int sun8i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
dev_dbg(ss->dev, "ERROR: Invalid keylen %u\n", keylen);
return -EINVAL;
}
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
op->keylen = keylen;
op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
- if (!op->key)
+ if (unlikely(!op->key))
+ op->keylen = 0;
return -ENOMEM;
+ }
crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
@@ -418,14 +413,13 @@ int sun8i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
return -EINVAL;
}
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
op->keylen = keylen;
op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
- if (!op->key)
+ if (unlikely(!op->key))
+ op->keylen = 0;
return -ENOMEM;
+ }
crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
diff --git a/drivers/crypto/amlogic/amlogic-gxl-cipher.c b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
index fd1269900d67..5312bad7534e 100644
--- a/drivers/crypto/amlogic/amlogic-gxl-cipher.c
+++ b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
@@ -341,10 +341,7 @@ void meson_cipher_exit(struct crypto_tfm *tfm)
{
struct meson_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
crypto_free_sync_skcipher(op->fallback_tfm);
}
@@ -368,14 +365,13 @@ int meson_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
dev_dbg(mc->dev, "ERROR: Invalid keylen %u\n", keylen);
return -EINVAL;
}
- if (op->key) {
- memzero_explicit(op->key, op->keylen);
- kfree(op->key);
- }
+ kfree_sensitive(op->key);
op->keylen = keylen;
op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
- if (!op->key)
+ if (unlikely(!op->key))
+ op->keylen = 0;
return -ENOMEM;
+ }
return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);
}
diff --git a/drivers/crypto/inside-secure/safexcel_hash.c b/drivers/crypto/inside-secure/safexcel_hash.c
index 43962bc709c6..4a2d162914de 100644
--- a/drivers/crypto/inside-secure/safexcel_hash.c
+++ b/drivers/crypto/inside-secure/safexcel_hash.c
@@ -1081,8 +1081,7 @@ static int safexcel_hmac_init_pad(struct ahash_request *areq,
}
/* Avoid leaking */
- memzero_explicit(keydup, keylen);
- kfree(keydup);
+ kfree_sensitive(keydup);
if (ret)
return ret;
--
2.18.1
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next prev parent reply other threads:[~2020-04-14 20:03 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-13 21:15 [PATCH 0/2] mm, treewide: Rename kzfree() to kfree_sensitive() Waiman Long
2020-04-13 21:15 ` [PATCH 1/2] " Waiman Long
2020-04-14 0:29 ` David Rientjes
2020-04-14 8:32 ` Jason A. Donenfeld
2020-04-14 9:01 ` Michal Hocko
2020-04-14 12:48 ` David Sterba
2020-04-14 18:26 ` Waiman Long
2020-04-15 5:01 ` Johannes Weiner
2020-06-15 18:07 ` Dan Carpenter
2020-06-15 18:39 ` Waiman Long
2020-04-13 21:15 ` [PATCH 2/2] crypto: Remove unnecessary memzero_explicit() Waiman Long
2020-04-13 21:31 ` Joe Perches
2020-04-13 21:52 ` Waiman Long
2020-04-13 22:28 ` [PATCH v2 " Waiman Long
2020-04-14 6:08 ` Christophe Leroy
2020-04-14 16:24 ` Waiman Long
2020-04-14 19:16 ` Michal Suchánek
2020-04-14 19:37 ` Waiman Long
2020-04-14 19:44 ` Joe Perches
2020-04-14 13:06 ` [PATCH 1/2] mm, treewide: Rename kzfree() to kfree_sensitive() David Howells
2020-04-14 20:02 ` Waiman Long [this message]
2020-04-16 9:06 ` [PATCH v3 2/3] crypto: Remove unnecessary memzero_explicit() Corentin Labbe
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