Return-Path: Received: from fieldses.org ([173.255.197.46]:43591 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753698AbbD2Pif (ORCPT ); Wed, 29 Apr 2015 11:38:35 -0400 Date: Wed, 29 Apr 2015 11:38:34 -0400 From: "J. Bruce Fields" To: Simo Sorce Cc: Scott Mayhew , linux-nfs@vger.kernel.org Subject: Re: [PATCH] svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures Message-ID: <20150429153834.GB18344@fieldses.org> References: <1430252993-20091-1-git-send-email-smayhew@redhat.com> <1430255365.13607.165.camel@willson.usersys.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1430255365.13607.165.camel@willson.usersys.redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Apr 28, 2015 at 05:09:25PM -0400, Simo Sorce wrote: > Thanks Scott, > I think this will help with older GSS-Proxy versions, in the newer > versions we are simply suppressing the exported composite name as the > kernel has no use for it. Thanks. (Also adding a Reviewed-by: Simo Sorce .) --b. > > Simo. > > On Tue, 2015-04-28 at 16:29 -0400, Scott Mayhew wrote: > > In an environment where the KDC is running Active Directory, the > > exported composite name field returned in the context could be large > > enough to span a page boundary. Attaching a scratch buffer to the > > decoding xdr_stream helps deal with those cases. > > > > Signed-off-by: Scott Mayhew > > --- > > net/sunrpc/auth_gss/gss_rpc_xdr.c | 23 ++++++++++++++++------- > > 1 file changed, 16 insertions(+), 7 deletions(-) > > > > diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c > > index 1ec19f6..eeeba5a 100644 > > --- a/net/sunrpc/auth_gss/gss_rpc_xdr.c > > +++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c > > @@ -793,20 +793,26 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp, > > { > > u32 value_follows; > > int err; > > + struct page *scratch; > > + > > + scratch = alloc_page(GFP_KERNEL); > > + if (!scratch) > > + return -ENOMEM; > > + xdr_set_scratch_buffer(xdr, page_address(scratch), PAGE_SIZE); > > > > /* res->status */ > > err = gssx_dec_status(xdr, &res->status); > > if (err) > > - return err; > > + goto out_free; > > > > /* res->context_handle */ > > err = gssx_dec_bool(xdr, &value_follows); > > if (err) > > - return err; > > + goto out_free; > > if (value_follows) { > > err = gssx_dec_ctx(xdr, res->context_handle); > > if (err) > > - return err; > > + goto out_free; > > } else { > > res->context_handle = NULL; > > } > > @@ -814,11 +820,11 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp, > > /* res->output_token */ > > err = gssx_dec_bool(xdr, &value_follows); > > if (err) > > - return err; > > + goto out_free; > > if (value_follows) { > > err = gssx_dec_buffer(xdr, res->output_token); > > if (err) > > - return err; > > + goto out_free; > > } else { > > res->output_token = NULL; > > } > > @@ -826,14 +832,17 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp, > > /* res->delegated_cred_handle */ > > err = gssx_dec_bool(xdr, &value_follows); > > if (err) > > - return err; > > + goto out_free; > > if (value_follows) { > > /* we do not support upcall servers sending this data. */ > > - return -EINVAL; > > + err = -EINVAL; > > + goto out_free; > > } > > > > /* res->options */ > > err = gssx_dec_option_array(xdr, &res->options); > > > > +out_free: > > + __free_page(scratch); > > return err; > > } > > > -- > Simo Sorce * Red Hat, Inc * New York