From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: [PATCH v2 2/2] crypto: Remove unnecessary memzero_explicit() Date: Mon, 13 Apr 2020 18:28:46 -0400 Message-ID: <20200413222846.24240-1-longman@redhat.com> References: <20200413211550.8307-1-longman@redhat.com> Return-path: In-Reply-To: <20200413211550.8307-1-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andrew Morton , David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Linus Torvalds , Joe Perches , Matthew Wilcox , David Rientjes Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, keyrings-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-crypto-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-stm32-XDFAJ8BFU24N7RejjzZ/Li2xQDfSxrLKVpNB7YpNyf8@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-amlogic-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, virtualization-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, intel-wired-lan-qjLDD68F18P21nG7glBr7A@public.gmane.org, linux-ppp-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, wireguard-/J5FBtcyxH5ZwnvJuMANYw@public.gmane.org, linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devel-gWbeCf7V1WCQmaza687I9mD2FQJk+8+b@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, target-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-btrfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org, linux-fscrypt-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ecryptfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan- List-Id: virtualization@lists.linuxfoundation.org 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, the setting of keylen is also moved down after the key pointer check. Signed-off-by: Waiman Long --- .../allwinner/sun8i-ce/sun8i-ce-cipher.c | 19 +++++------------- .../allwinner/sun8i-ss/sun8i-ss-cipher.c | 20 +++++-------------- drivers/crypto/amlogic/amlogic-gxl-cipher.c | 12 +++-------- drivers/crypto/inside-secure/safexcel_hash.c | 3 +-- 4 files changed, 14 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..8358fac98719 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 +388,11 @@ 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); - } - op->keylen = keylen; + kfree_sensitive(op->key); op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA); if (!op->key) return -ENOMEM; + op->keylen = keylen; 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 +410,11 @@ 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); - } - op->keylen = keylen; + kfree_sensitive(op->key); op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA); if (!op->key) return -ENOMEM; + op->keylen = keylen; 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..0495fbc27fcc 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 +388,11 @@ 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); - } - op->keylen = keylen; + kfree_sensitive(op->key); op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA); if (!op->key) return -ENOMEM; + op->keylen = keylen; 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 +411,11 @@ 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); - } - op->keylen = keylen; + kfree_sensitive(op->key); op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA); if (!op->key) return -ENOMEM; + op->keylen = keylen; 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..6aa9ce7bbbd4 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 +365,11 @@ 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); - } - op->keylen = keylen; + kfree_sensitive(op->key); op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA); if (!op->key) return -ENOMEM; + op->keylen = keylen; 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