Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:36315 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030931AbbD1VJ1 (ORCPT ); Tue, 28 Apr 2015 17:09:27 -0400 Message-ID: <1430255365.13607.165.camel@willson.usersys.redhat.com> Subject: Re: [PATCH] svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures From: Simo Sorce To: Scott Mayhew Cc: bfields@fieldses.org, linux-nfs@vger.kernel.org Date: Tue, 28 Apr 2015 17:09:25 -0400 In-Reply-To: <1430252993-20091-1-git-send-email-smayhew@redhat.com> References: <1430252993-20091-1-git-send-email-smayhew@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org List-ID: 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. 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