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 C99B056D2BD; Mon, 31 Aug 2026 13:48:27 +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=1788184109; cv=none; b=UOWcJ9fBVISmV2sO3tu8Bk0j85g9K01qUesZDp8bnIk6XYl1VIcOO0ftvsDs21L12Hw0ob0fccoUx6RI7bb9+nI9QZYRpdGNWfvHgTMxOdpmX7N50KgT7+qwkyIxmNMpuEsJRGADkbK6cqjiRTTQ7eFeMR20hwOT5xs9DZNmpgQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788184109; c=relaxed/simple; bh=Nm7IQUmay48BoT5xJ+ZYEmKa8bZ6PrImhiodZayVonM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AUEEN8i3iBDAPnb6r0xXu0H2fqEXZ6dA6GGWnQX3m+aNdZnpEqceuInXSlOJCGVV7Fh1tDCbxxHrbtfQu7O+N6r62xIo6MmxNGG9fM+bE42T6q85BAGmmOr8WkuGRGj3HUW9RRGZ+3oY2KMi+Wpm25a5XsO33YPHDif2AYYbteU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HNxN/7Vy; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HNxN/7Vy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 326091F00ACA; Mon, 31 Aug 2026 13:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788184107; bh=4sqOakWCCOTEyaHLWiKtxI8CNowvRJC19JFc9IzSlMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HNxN/7VyLV/tyi0NyCKHllEErNXcLh9dlkcLhH8vgDKaHrYKmO/et5CckPgpvK9ur Xh4D5gS6BjraiMo4WX9yzcwzdsZVKhazI6aWWl25Rf6uRLRYOc5V2ZPbQ+8oO0oTBA Q5hriLo9LSac3gMCtgrDG+9RN+ccyBv3E4bhLMzY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Borntraeger , Claudio Imbrenda Subject: [PATCH 6.18 74/83] KVM: s390: vsie: zero stale crypto bits Date: Mon, 31 Aug 2026 15:34:50 +0200 Message-ID: <20260831133403.211514063@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133359.207714926@linuxfoundation.org> References: <20260831133359.207714926@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Borntraeger commit 34d5b5b646c91cfb9338d7a12c955a70ffb8c66b upstream. When shadowing crypto access bits from a format0 apcb (crycb 0 or 1), the bits 64..255 are unchanged from whatever is in the vsie page in the crycb and thus in the apcb. This gives a nested guest potential access to a device no longer available. Zero out the remaining bits. Fixes: 6b79de4b056e ("KVM: s390: vsie: allow guest FORMAT-1 CRYCB on host FORMAT-2") Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger Reviewed-by: Claudio Imbrenda Signed-off-by: Claudio Imbrenda Message-ID: <20260811153738.206885-3-borntraeger@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/vsie.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -184,6 +184,7 @@ static int setup_apcb10(struct kvm_vcpu sizeof(struct kvm_s390_apcb0))) return -EFAULT; + memset(apcb_s, 0, sizeof(*apcb_s)); apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0]; apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL; apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL;