From: Corentin Labbe <clabbe.montjoie@gmail.com>
To: Waiman Long <longman@redhat.com>
Cc: linux-crypto@vger.kernel.org,
Herbert Xu <herbert@gondor.apana.org.au>,
James Morris <jmorris@namei.org>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
linux-mm@kvack.org, Chen-Yu Tsai <wens@csie.org>,
keyrings@vger.kernel.org, Matthew Wilcox <willy@infradead.org>,
David Rientjes <rientjes@google.com>,
Joe Perches <joe@perches.com>,
linux-amlogic@lists.infradead.org,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
"David S. Miller" <davem@davemloft.net>,
linux-arm-kernel@lists.infradead.org,
"Serge E. Hallyn" <serge@hallyn.com>
Subject: Re: [PATCH v3 2/3] crypto: Remove unnecessary memzero_explicit()
Date: Thu, 16 Apr 2020 11:06:18 +0200 [thread overview]
Message-ID: <20200416090618.GB29148@Red> (raw)
In-Reply-To: <20200414200214.1873-1-longman@redhat.com>
On Tue, Apr 14, 2020 at 04:02:14PM -0400, Waiman Long wrote:
> 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);
> }
For sun8i-ss/sun8i-ce
Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com>
For amlogic
Acked-by: Corentin Labbe <clabbe@baylibre.com>
Thanks
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linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
prev parent reply other threads:[~2020-04-16 9:06 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 ` [PATCH v3 2/3] crypto: Remove unnecessary memzero_explicit() Waiman Long
2020-04-16 9:06 ` Corentin Labbe [this message]
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