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 A6C3848AE35; Mon, 31 Aug 2026 14:05:24 +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=1788185126; cv=none; b=eVmE6Lt8Zl1FZIeAAqgTUWU0K+mMIZlmv1vAV5r2UxauWvazm+dbyezA+R5TWClIkgxqR45JOnrrQtYQ+2K0BfxsCR0AfQgY2kpsUByYwT2W3/tDMRwvh9UORgjASn0T+c/KrARETUApD38+ioBMP7pYQKmVS/WMieD7Krb7bVc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788185126; c=relaxed/simple; bh=LZ2u0h75qTDA1Ix1WB6R6LJi8nF3d+lnDMo+lP5fIuU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=S21pzzZ0J0IzJx+pdtHqwNCFNQCNNbY4Pm9cFhmtBejhehGgyxcSg3Vqxc1X/1/+sCcA/bV3OQUS4sM1pcpmJAvo0DyTZGG9MAXR+RqekFG/bYRLeSjXWEIMAOjlzRhp+1CUFOwf+1WjOOxmhpdzwWqigVo3kkNO28D1C1TAgGs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A4KDLtlF; 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="A4KDLtlF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03CD91F000E9; Mon, 31 Aug 2026 14:05:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788185124; bh=qYGZTe37cqiAHdKKRK+HYezfKzx6pFyCyP+AKBYDjcg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=A4KDLtlF4nUIIsHvg9/wonO+lotIsV/xcCXS33/jn/BdH8jEhIYtnh1MVeJmckMHr CD7QXhZJ/KsvJi7dJqX7oUYlKfsbA8xAEprw4uQZPhwKG5tIg3lizkM2tizOwlFm9j ytHIhC6Ms9EBV6MCduD1+DOZOvb2JhmIDR5XsNhY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Borntraeger , Claudio Imbrenda Subject: [PATCH 5.15 61/69] KVM: s390: vsie: zero stale crypto bits Date: Mon, 31 Aug 2026 15:35:34 +0200 Message-ID: <20260831133401.790070344@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133358.601894154@linuxfoundation.org> References: <20260831133358.601894154@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 5.15-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 @@ -145,6 +145,7 @@ static int setup_apcb10(struct kvm_vcpu if (read_guest_real(vcpu, apcb_o, &tmp, 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;