From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 12A60606A32D for ; Mon, 26 Oct 2026 11:52:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=FB9R7QKD Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xLJEU-0003ge-D7; Mon, 26 Oct 2026 07:51:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xLJES-0003gK-JY for qemu-devel@nongnu.org; Mon, 26 Oct 2026 07:51:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xLJEQ-000334-Rh for qemu-devel@nongnu.org; Mon, 26 Oct 2026 07:51:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1793015473; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=x7JbnTc+Gviorm5yeoE+Jc3DK41YdYSAUR5tB7B2yrw=; b=FB9R7QKDX+v3svr+JWMNonXQotUmnsUyCG4KrUu04KIxJ/p5GzE0JpGV+PlXx+EzE8K3nm +ym53OKjxBQBRVOR7e2oxLlRmP9R3l6G3cWzjGIUdbyEyzqfsDuF2vhUR30bTIovrDnicf uitpT9y9e1vQzAAUdYLPRGN7yQo67W8= 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-573-G816QjYyOsqyM5VMEyytBQ-1; Mon, 26 Oct 2026 07:51:05 -0400 X-MC-Unique: G816QjYyOsqyM5VMEyytBQ-1 X-Mimecast-MFC-AGG-ID: G816QjYyOsqyM5VMEyytBQ_1793015464 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 D06151954B13 for ; Mon, 26 Oct 2026 11:51:04 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.44.22.2]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8FE511800345 for ; Mon, 26 Oct 2026 11:51:04 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 3697321E6A04; Mon, 26 Oct 2026 12:51:02 +0100 (CET) From: Markus Armbruster To: Daniel P. =?utf-8?Q?Berrang=C3=A9?= Cc: qemu-devel@nongnu.org, marcandre.lureau@redhat.com Subject: Re: [PATCH v2 1/2] crypto: avoid overwriting Error object erasing keyslot In-Reply-To: <20261026111237.660633-2-berrange@redhat.com> ("Daniel P. =?utf-8?Q?Berrang=C3=A9=22's?= message of "Mon, 26 Oct 2026 11:12:36 +0000") References: <20261026111237.660633-1-berrange@redhat.com> <20261026111237.660633-2-berrange@redhat.com> Date: Mon, 26 Oct 2026 12:51:02 +0100 Message-ID: <878q3k3ck9.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 2 X-Spam_score: 0.2 X-Spam_bar: / X-Spam_report: (0.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.339, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-22.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Daniel P. Berrang=C3=A9 writes: > When erasing a keyslot we deliberately ignore some errors and > carry on trying to erase as much as possible. This results in > overwriting Error objects and triggering an assertion. Don't > pass in the &local_err, if errp is already set. > > Fixes: https://gitlab.com/qemu-project/qemu/-/work_items/4697 > Signed-off-by: Daniel P. Berrang=C3=A9 > --- > crypto/block-luks.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > index 0926ad28f0c..277a5110607 100644 > --- a/crypto/block-luks.c > +++ b/crypto/block-luks.c > @@ -1152,6 +1152,7 @@ qcrypto_block_luks_erase_key(QCryptoBlock *block, { QCryptoBlockLUKS *luks =3D block->opaque; QCryptoBlockLUKSKeySlot *slot; g_autofree uint8_t *garbagesplitkey =3D NULL; size_t splitkeylen; size_t i; Error *local_err =3D NULL; int ret; assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); slot =3D &luks->header.key_slots[slot_idx]; splitkeylen =3D luks->header.master_key_len * slot->stripes; assert(splitkeylen > 0); garbagesplitkey =3D g_new0(uint8_t, splitkeylen); /* Reset the key slot header */ memset(slot->salt, 0, QCRYPTO_BLOCK_LUKS_SALT_LEN); slot->iterations =3D 0; slot->active =3D QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; ret =3D qcrypto_block_luks_store_header(block, writefunc, opaque, &local_err); Why not pass @errp here, and ... >=20=20 > if (ret < 0) { > error_propagate(errp, local_err); ... drop this line? > + local_err =3D NULL; > } Suggest a blank line here. Note for later: @errp may be non-null now. > /* > * Now try to erase the key material, even if the header > @@ -1169,6 +1170,7 @@ qcrypto_block_luks_erase_key(QCryptoBlock *block, * update failed */ for (i =3D 0; i < QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS; i++) { if (qcrypto_random_bytes(garbagesplitkey, splitkeylen, &local_err) < 0) { /* * If we failed to get the random data, still write * at least zeros to the key slot at least once */ error_propagate(errp, local_err); If @errp is still null, store this error, else ignore it. > if (i > 0) { > return -1; Stop when erasing non-first key slot failed. > } > + local_err =3D NULL; > } > if (writefunc(block, > slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTO= R_SIZE, garbagesplitkey, splitkeylen, opaque, &local_err) < 0) { error_propagate(errp, local_err); We do need error_propagate() here, because @errp can be non-null. return -1; } } return ret; } Nothing is wrong, so Reviewed-by: Markus Armbruster