From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162695AbdEWVXJ (ORCPT ); Tue, 23 May 2017 17:23:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49420 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033183AbdEWUd7 (ORCPT ); Tue, 23 May 2017 16:33:59 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jani Tuovila , Ari Kauppi , Dan Carpenter , Christoph Hellwig , "J. Bruce Fields" Subject: [PATCH 4.9 161/164] nfsd: fix undefined behavior in nfsd4_layout_verify Date: Tue, 23 May 2017 22:09:38 +0200 Message-Id: <20170523200913.972524789@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200907.297534241@linuxfoundation.org> References: <20170523200907.297534241@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ari Kauppi commit b550a32e60a4941994b437a8d662432a486235a5 upstream. UBSAN: Undefined behaviour in fs/nfsd/nfs4proc.c:1262:34 shift exponent 128 is too large for 32-bit type 'int' Depending on compiler+architecture, this may cause the check for layout_type to succeed for overly large values (which seems to be the case with amd64). The large value will be later used in de-referencing nfsd4_layout_ops for function pointers. Reported-by: Jani Tuovila Signed-off-by: Ari Kauppi [colin.king@canonical.com: use LAYOUT_TYPE_MAX instead of 32] Reviewed-by: Dan Carpenter Reviewed-by: Christoph Hellwig Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4proc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1273,7 +1273,8 @@ nfsd4_layout_verify(struct svc_export *e return NULL; } - if (!(exp->ex_layout_types & (1 << layout_type))) { + if (layout_type >= LAYOUT_TYPE_MAX || + !(exp->ex_layout_types & (1 << layout_type))) { dprintk("%s: layout type %d not supported\n", __func__, layout_type); return NULL;