From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 16 Apr 2020 11:06:18 +0200 From: Corentin Labbe Subject: Re: [PATCH v3 2/3] crypto: Remove unnecessary memzero_explicit() Message-ID: <20200416090618.GB29148@Red> References: <20200413211550.8307-1-longman@redhat.com> <20200414200214.1873-1-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200414200214.1873-1-longman@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Waiman Long Cc: Andrew Morton , David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Linus Torvalds , Joe Perches , Matthew Wilcox , David Rientjes , Herbert Xu , "David S. Miller" , Chen-Yu Tsai , linux-mm@kvack.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org 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 > --- > .../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 For amlogic Acked-by: Corentin Labbe Thanks