Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:48362 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965258AbbD1U3z (ORCPT ); Tue, 28 Apr 2015 16:29:55 -0400 From: Scott Mayhew To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH] svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures Date: Tue, 28 Apr 2015 16:29:53 -0400 Message-Id: <1430252993-20091-1-git-send-email-smayhew@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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; } -- 1.9.3