From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18DA9C83008 for ; Tue, 28 Apr 2020 18:39:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF89320575 for ; Tue, 28 Apr 2020 18:38:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099140; bh=2yWQ2COUuuTnHoBxyQRtu+KP95CUyMOunznIYckENiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uHJ7TmxZpPpSCKMeb9eyPjqw0KHYNYdSZQ3YE85vLfakYFQY5D7kvpMmaluBvd2+s JjboRx6xIn7acXeFegc+mmv/9f3fYOcSlJETr4rCQEh2scMrm9q2Yl5TOGFEAMqg8J r0krthEUx6E9fBKQ5+22xNZgwKmW3LTdUfJwLyKo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730144AbgD1Si7 (ORCPT ); Tue, 28 Apr 2020 14:38:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:57616 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729821AbgD1Si4 (ORCPT ); Tue, 28 Apr 2020 14:38:56 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E690320575; Tue, 28 Apr 2020 18:38:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099136; bh=2yWQ2COUuuTnHoBxyQRtu+KP95CUyMOunznIYckENiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zdG4mYu8CyB401s0vYezQLp1XgNfWxsRT0lSsl4tScnayPZ5GFP96L/Fw8C/dP4E4 H4yY5YbT3ezJ5wHGQpV61AozvZRnW/FDKqrHpvfl0Eu5MYrp63xe4tXvLCCEqbqA1I Rmd9+bJ/ZOhzCwKXmTYeajNbf3rcAXwbLp+yYh8o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Cornelia Huck , Paolo Bonzini Subject: [PATCH 4.19 101/131] KVM: s390: Return last valid slot if approx index is out-of-bounds Date: Tue, 28 Apr 2020 20:25:13 +0200 Message-Id: <20200428182237.821244600@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182224.822179290@linuxfoundation.org> References: <20200428182224.822179290@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Christopherson commit 97daa028f3f621adff2c4f7b15fe0874e5b5bd6c upstream. Return the index of the last valid slot from gfn_to_memslot_approx() if its binary search loop yielded an out-of-bounds index. The index can be out-of-bounds if the specified gfn is less than the base of the lowest memslot (which is also the last valid memslot). Note, the sole caller, kvm_s390_get_cmma(), ensures used_slots is non-zero. Fixes: afdad61615cc3 ("KVM: s390: Fix storage attributes migration with memory slots") Cc: stable@vger.kernel.org # 4.19.x: 0774a964ef56: KVM: Fix out of range accesses to memslots Cc: stable@vger.kernel.org # 4.19.x Signed-off-by: Sean Christopherson Message-Id: <20200408064059.8957-3-sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/kvm-s390.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1666,6 +1666,9 @@ static int gfn_to_memslot_approx(struct start = slot + 1; } + if (start >= slots->used_slots) + return slots->used_slots - 1; + if (gfn >= memslots[start].base_gfn && gfn < memslots[start].base_gfn + memslots[start].npages) { atomic_set(&slots->lru_slot, start);