From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 49DB836AB4D; Fri, 7 Aug 2026 07:41:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786088462; cv=none; b=ufqTWoJLivMaFBB9U/9qZExhO0anXPJFuQk850+/pwmSuJ2FolrsLmr1dc38siY7eDWbj6ZABHO2/4oGBhTo+hj68FFhDQT771Dc9Qe7gsQbQ5xdBcju938VgvjJ7gCQn09UKRiF+/TNNxdXg/SZJdCSqjAxFl84AeHxkZ2GwDY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786088462; c=relaxed/simple; bh=26vAjamIDeOMJbwdF2UtqXVRqoVZaFO0wARZfvcl9cA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gBzVu6DHjGIbjyFQWN3VBF8v+r5Tfh9SXZ1ZMvNufroMsC/qClEWM37cMepeTRUwq6QU0t6XrHXPNnxedY2BZz9G7l7OXQ4l3BaTZCRPAl3g8zRWKhKx/4JRefUGbMWNho65xsn58o8Ik/6Pq65bsb6eSih1XK5bdTeWeuR3qzI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Mx/4WtJl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Mx/4WtJl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 969BE1F000E9; Fri, 7 Aug 2026 07:41:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786088460; bh=lNuaTCGlk2E7mtE6kVOMno0eYlruMIFjvJrFVQhRnU4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Mx/4WtJl2B+2V4CWOL8k1s7vOCiz7PZtLrjerWZihF1wjkSzaULf2mCYOyfU9F97j 7Mfyfw3lmUjeLoNHg7cuqjjMAhQ1gufcStzXgsy7BZBTQQ0HIMyNoyeVSQWdjVIukU lP3Z9g397X3Td6pxgvnLkS3UYU8Ib1DSN4PdBGwYcelnidZ5tGnAk6F/UMKGmS8gm+ F8ryEaMNEBPXkAl1/vwdXPa+CZkA9N/u2A55gIAuSPUsNmIFMvBty83hWNPxwZ6T77 gzSGTB1sGO6gFm7/13fB3SF16xhoBKIl/A+8YEGIZfT2kpTD1kqLoRV1aZQ9JxAoa8 1TtaO6KrbFa8A== Date: Fri, 7 Aug 2026 09:40:58 +0200 From: Antoine Tenart To: Thomas Huth Cc: Herbert Xu , "David S. Miller" , Antoine Tenart , linux-crypto@vger.kernel.org, Eric Biggers , linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 09/10] crypto: safexcel - Rework cleanup of sensitive structs in safexcel_aead_setkey Message-ID: References: <20260807070651.228713-1-thuth@redhat.com> <20260807070651.228713-10-thuth@redhat.com> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260807070651.228713-10-thuth@redhat.com> On Fri, Aug 07, 2026 at 09:06:36AM +0200, Thomas Huth wrote: > From: Thomas Huth > > The crypto_authenc_keys structure only contains pointers to keys, but not > the key data itself. So explicitly clearing the structure at the end of > safexcel_aead_setkey() is not really necessary, see Eric's recommendation > here: > > https://lore.kernel.org/linux-crypto/20260804185402.GD2904385@google.com/ > > On the other hand, the crypto_aes_ctx might contain sensitive information, > so this structure should be cleaned up at the end instead. Do this > now via the new __cleanup(aes_zeroize_ctx) marker. > > Since __cleanup() and gotos should not be mixed in the same function, > replace the gotos with early return statements, which is fine now that > we dropped the memzero_explicit(&keys, sizeof(keys)) at the end. > > Suggested-by: Eric Biggers > Signed-off-by: Thomas Huth Reviewed-by: Antoine Tenart > --- > .../crypto/inside-secure/safexcel_cipher.c | 27 ++++++++----------- > 1 file changed, 11 insertions(+), 16 deletions(-) > > diff --git a/drivers/crypto/inside-secure/safexcel_cipher.c b/drivers/crypto/inside-secure/safexcel_cipher.c > index a8349b684693e..c331d81ac8a2d 100644 > --- a/drivers/crypto/inside-secure/safexcel_cipher.c > +++ b/drivers/crypto/inside-secure/safexcel_cipher.c > @@ -407,17 +407,17 @@ static int safexcel_aead_setkey(struct crypto_aead *ctfm, const u8 *key, > struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm); > struct safexcel_crypto_priv *priv = ctx->base.priv; > struct crypto_authenc_keys keys; > - struct crypto_aes_ctx aes; > - int err = -EINVAL, i; > + struct crypto_aes_ctx aes __cleanup(aes_zeroize_ctx); > + int err, i; > const char *alg; > > if (unlikely(crypto_authenc_extractkeys(&keys, key, len))) > - goto badkey; > + return -EINVAL; > > if (ctx->mode == CONTEXT_CONTROL_CRYPTO_MODE_CTR_LOAD) { > /* Must have at least space for the nonce here */ > if (unlikely(keys.enckeylen < CTR_RFC3686_NONCE_SIZE)) > - goto badkey; > + return -EINVAL; > /* last 4 bytes of key are the nonce! */ > ctx->nonce = *(u32 *)(keys.enckey + keys.enckeylen - > CTR_RFC3686_NONCE_SIZE); > @@ -430,25 +430,25 @@ static int safexcel_aead_setkey(struct crypto_aead *ctfm, const u8 *key, > case SAFEXCEL_DES: > err = verify_aead_des_key(ctfm, keys.enckey, keys.enckeylen); > if (unlikely(err)) > - goto badkey; > + return err; > break; > case SAFEXCEL_3DES: > err = verify_aead_des3_key(ctfm, keys.enckey, keys.enckeylen); > if (unlikely(err)) > - goto badkey; > + return err; > break; > case SAFEXCEL_AES: > err = aes_expandkey(&aes, keys.enckey, keys.enckeylen); > if (unlikely(err)) > - goto badkey; > + return err; > break; > case SAFEXCEL_SM4: > if (unlikely(keys.enckeylen != SM4_KEY_SIZE)) > - goto badkey; > + return -EINVAL; > break; > default: > dev_err(priv->dev, "aead: unsupported cipher algorithm\n"); > - goto badkey; > + return -EINVAL; > } > > if (priv->flags & EIP197_TRC_CACHE && ctx->base.ctxr_dma) { > @@ -486,24 +486,19 @@ static int safexcel_aead_setkey(struct crypto_aead *ctfm, const u8 *key, > break; > default: > dev_err(priv->dev, "aead: unsupported hash algorithm\n"); > - goto badkey; > + return -EINVAL; > } > > if (safexcel_hmac_setkey(&ctx->base, keys.authkey, keys.authkeylen, > alg, ctx->state_sz)) > - goto badkey; > + return -EINVAL; > > /* Now copy the keys into the context */ > for (i = 0; i < keys.enckeylen / sizeof(u32); i++) > ctx->key[i] = cpu_to_le32(((u32 *)keys.enckey)[i]); > ctx->key_len = keys.enckeylen; > > - memzero_explicit(&keys, sizeof(keys)); > return 0; > - > -badkey: > - memzero_explicit(&keys, sizeof(keys)); > - return err; > } > > static int safexcel_context_control(struct safexcel_cipher_ctx *ctx, > -- > 2.55.0 >