Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964942AbbFJPam (ORCPT ); Wed, 10 Jun 2015 11:30:42 -0400 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:36095 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754260AbbFJP1o (ORCPT ); Wed, 10 Jun 2015 11:27:44 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Scott Mayhew , "J. Bruce Fields" , Jiri Slaby Subject: [PATCH 3.12 075/111] svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures Date: Wed, 10 Jun 2015 17:27:04 +0200 Message-Id: X-Mailer: git-send-email 2.4.2 In-Reply-To: <93091169a673f49c2574cddf1ef858cf0704f646.1433943052.git.jslaby@suse.cz> References: <93091169a673f49c2574cddf1ef858cf0704f646.1433943052.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2840 Lines: 100 From: Scott Mayhew 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 9507271d960a1911a51683888837d75c171cd91f upstream. 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. The case where we saw this was actually due to behavior that's been fixed in newer gss-proxy versions, but we're fixing it here too. Signed-off-by: Scott Mayhew Reviewed-by: Simo Sorce Signed-off-by: J. Bruce Fields Signed-off-by: Jiri Slaby --- 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 f0f78c5f1c7d..e0062c544ac8 100644 --- a/net/sunrpc/auth_gss/gss_rpc_xdr.c +++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c @@ -794,20 +794,26 @@ 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; } @@ -815,11 +821,11 @@ 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; } @@ -827,14 +833,17 @@ 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; } -- 2.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/