From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 4FF013DCD95 for ; Thu, 10 Sep 2026 12:42:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789044123; cv=none; b=iS9QkFlpN6wQwZvT1C/5spLp9hBbPTw4Ci/F5SxADscEEvwYn0On5SyxS9+F1A0dQBEUbiIW5hDyeZHe3YJvb+CrkvRMPbdM4EckcmANFV6VY0qxyfErR7x/jd2jFUiEwlNSZFMXWxRwPlYJMzGdC1RpBIgLM9Vs/XAEa+5+kv4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789044123; c=relaxed/simple; bh=Pu553ZQkM91B4VrsGc9weFb5s0yBfWGWM2iMrF015hs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mpniaJTwQo/Pix7SsB9kUEBdox27ee+1m5WxicLfIAT6oMOkMuByzGS9C6WXYjTG1SWL0dUDOFpnT6Y1O4W7C0lrLFbWka+S7OU74uEtIdzd/itKDgbDs3IsnzJ1eqzuPH3Ae87muT+Xi3fFlmRKEvGDuQPWb4dvbsI8qC/hH+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=NVPxIY1G; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NVPxIY1G" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1789044118; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iKydTuaKi3XtSbexoPJB1tXNpcTYcsS4RpRAKal/7tc=; b=NVPxIY1GcuvUI/CuIkort2MXj5Lik1Nqx/inUT00xvrs9+FIE1P+K5ORYn9DRFoSdBat3X IpIDQXFe4X6vAMMemhmIBM/Ql9yfmTdEps9jrqmlz8B91yz6QhX+vRLO1l3QWeJfrAGuzk 8DBsLsFENIt8muUVioivOCmis2Wm0eE= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-657-UKNCLXBSPXql7KfXoqJSQw-1; Thu, 10 Sep 2026 08:41:55 -0400 X-MC-Unique: UKNCLXBSPXql7KfXoqJSQw-1 X-Mimecast-MFC-AGG-ID: UKNCLXBSPXql7KfXoqJSQw_1789044113 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 458771954214; Thu, 10 Sep 2026 12:41:53 +0000 (UTC) Received: from thuth-p1g4.redhat.corp (headnet03.pony-001.prod.iad2.dc.redhat.com [10.2.32.114]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 594D230001A2; Thu, 10 Sep 2026 12:41:49 +0000 (UTC) From: Thomas Huth To: Eric Biggers , Herbert Xu , "David S. Miller" , "Jason A. Donenfeld" , Ard Biesheuvel Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen Subject: [PATCH v3 02/13] lib/crypto: aes-xts: Provide function for zeroizing aes_xts_key Date: Thu, 10 Sep 2026 14:41:21 +0200 Message-ID: <20260910124138.417439-3-thuth@redhat.com> In-Reply-To: <20260910124138.417439-1-thuth@redhat.com> References: <20260910124138.417439-1-thuth@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 In certain cases crypto code functions need to zeroize their local aes_xts_key structures after use to avoid leaking sensitive material. Provide an aes_xts_zeroize_key() helper function that e.g. can be used with __cleanup() to automatically zeroize the struct when it goes out of scope. While we're at it, replace the related memzero_explicit() call in lib/crypto/aes.c with a call to the new helper function. Signed-off-by: Thomas Huth --- include/crypto/aes-xts.h | 13 +++++++++++-- lib/crypto/aes.c | 2 +- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/include/crypto/aes-xts.h b/include/crypto/aes-xts.h index b9e828265e58a..3a52e1cf40b57 100644 --- a/include/crypto/aes-xts.h +++ b/include/crypto/aes-xts.h @@ -22,6 +22,15 @@ struct aes_xts_key { struct aes_enckey tweak_key; }; +/** + * aes_xts_zeroize_key() - Zeroize an aes_xts_key structure + * @key: The aes_xts_key to zeroize + */ +static inline void aes_xts_zeroize_key(struct aes_xts_key *key) +{ + memzero_explicit(key, sizeof(*key)); +} + /** * aes_xts_preparekey() - Prepare a key for AES-XTS encryption and decryption * @key: (output) The key structure to initialize @@ -30,8 +39,8 @@ struct aes_xts_key { * @flags: Optional flag XTS_FORBID_WEAK_KEYS to forbid keys whose two halves * are the same. * - * Users should use memzero_explicit() to zeroize the key struct at the end of - * its lifetime. (But if this function fails, zeroization is unnecessary.) + * Users should use aes_xts_zeroize_key() to zeroize the key struct at the end + * of its lifetime. (But if this function fails, zeroization is unnecessary.) * * Context: Any context. * Return: diff --git a/lib/crypto/aes.c b/lib/crypto/aes.c index 07c1d912ac365..34ef5deca0a79 100644 --- a/lib/crypto/aes.c +++ b/lib/crypto/aes.c @@ -1223,7 +1223,7 @@ int aes_xts_preparekey(struct aes_xts_key *key, const u8 *in_key, return 0; out_zeroize: - memzero_explicit(key, sizeof(*key)); + aes_xts_zeroize_key(key); return err; } EXPORT_SYMBOL_GPL(aes_xts_preparekey); -- 2.55.0