From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49434 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033210AbdEWUeI (ORCPT ); Tue, 23 May 2017 16:34:08 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ari Kauppi , Christoph Hellwig , "J. Bruce Fields" Subject: [PATCH 4.9 162/164] nfsd: encoders mustnt use unitialized values in error cases Date: Tue, 23 May 2017 22:09:39 +0200 Message-Id: <20170523200914.016363356@linuxfoundation.org> In-Reply-To: <20170523200907.297534241@linuxfoundation.org> References: <20170523200907.297534241@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: J. Bruce Fields commit f961e3f2acae94b727380c0b74e2d3954d0edf79 upstream. In error cases, lgp->lg_layout_type may be out of bounds; so we shouldn't be using it until after the check of nfserr. This was seen to crash nfsd threads when the server receives a LAYOUTGET request with a large layout type. GETDEVICEINFO has the same problem. Reported-by: Ari Kauppi Reviewed-by: Christoph Hellwig Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4xdr.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -4081,8 +4081,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_ struct nfsd4_getdeviceinfo *gdev) { struct xdr_stream *xdr = &resp->xdr; - const struct nfsd4_layout_ops *ops = - nfsd4_layout_ops[gdev->gd_layout_type]; + const struct nfsd4_layout_ops *ops; u32 starting_len = xdr->buf->len, needed_len; __be32 *p; @@ -4099,6 +4098,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_ /* If maxcount is 0 then just update notifications */ if (gdev->gd_maxcount != 0) { + ops = nfsd4_layout_ops[gdev->gd_layout_type]; nfserr = ops->encode_getdeviceinfo(xdr, gdev); if (nfserr) { /* @@ -4151,8 +4151,7 @@ nfsd4_encode_layoutget(struct nfsd4_comp struct nfsd4_layoutget *lgp) { struct xdr_stream *xdr = &resp->xdr; - const struct nfsd4_layout_ops *ops = - nfsd4_layout_ops[lgp->lg_layout_type]; + const struct nfsd4_layout_ops *ops; __be32 *p; dprintk("%s: err %d\n", __func__, nfserr); @@ -4175,6 +4174,7 @@ nfsd4_encode_layoutget(struct nfsd4_comp *p++ = cpu_to_be32(lgp->lg_seg.iomode); *p++ = cpu_to_be32(lgp->lg_layout_type); + ops = nfsd4_layout_ops[lgp->lg_layout_type]; nfserr = ops->encode_layoutget(xdr, lgp); out: kfree(lgp->lg_content);