From 5277fc4d0393ffe2e415ad26610b36d2986c62d7 Mon Sep 17 00:00:00 2001 From: Andreas Schneider Date: Thu, 20 Mar 2014 14:45:01 +0100 Subject: [PATCH] s3-rpc_server: Fix handling of fragmented rpc requests. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We need to call pipe_init_outgoing_data() as the first thing in process_complete_pdu(). Otherwise the caller may use uninitialized memory and tries to write a response into the socket. The problem happens only if a real socket is used, which means in all cases for master and only with external rpc daemons in v4-0 and v4-1. The problem looks like this in the logs. [2014/03/20 14:49:35.531663, 10, pid=7309, effective(0, 0), real(0, 0), class=rpc_srv] ../source3/rpc_server/srv_pipe.c:1627(process_complete_pdu) Processing packet type 0 [2014/03/20 14:49:35.531695, 10, pid=7309, effective(0, 0), real(0, 0), class=rpc_srv] ../source3/rpc_server/srv_pipe.c:1472(dcesrv_auth_request) Checking request auth. [2014/03/20 14:49:35.531738, 10, pid=7309, effective(0, 0), real(0, 0)] ../source3/rpc_server/rpc_server.c:521(named_pipe_packet_process) Sending 1 fragments in a total of 0 bytes [2014/03/20 14:49:35.531769, 10, pid=7309, effective(0, 0), real(0, 0)] ../source3/rpc_server/rpc_server.c:526(named_pipe_packet_process) Sending PDU number: 0, PDU Length: 4294967228 [2014/03/20 14:49:35.531801, 2, pid=7309, effective(0, 0), real(0, 0)] ../source3/rpc_server/rpc_server.c:565(named_pipe_packet_done) Writev failed! [2014/03/20 14:49:35.531845, 2, pid=7309, effective(0, 0), real(0, 0)] ../source3/rpc_server/rpc_server.c:595(named_pipe_packet_done) Fatal error(Message too long). Terminating client(127.0.0.1) connection! BUG: https://bugzilla.samba.org/show_bug.cgi?id=10481 Pair-Programmed-With: Stefan Metzmacher Signed-off-by: Andreas Schneider Reviewed-by: Guenther Deschner Autobuild-Date(master): Thu Mar 20 18:30:17 CET 2014 on sn-devel-104 --- source3/rpc_server/srv_pipe.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/source3/rpc_server/srv_pipe.c b/source3/rpc_server/srv_pipe.c index 36864d26045..67c9a68b984 100644 --- a/source3/rpc_server/srv_pipe.c +++ b/source3/rpc_server/srv_pipe.c @@ -1547,9 +1547,6 @@ static bool process_request_pdu(struct pipes_struct *p, struct ncacn_packet *pkt * Ok - we finally have a complete RPC stream. * Call the rpc command to process it. */ - if (!pipe_init_outgoing_data(p)) { - return false; - } return api_pipe_request(p, pkt); } @@ -1563,6 +1560,10 @@ void process_complete_pdu(struct pipes_struct *p, struct ncacn_packet *pkt) DEBUG(10, ("Processing packet type %u\n", (unsigned int)pkt->ptype)); + if (!pipe_init_outgoing_data(p)) { + goto done; + } + switch (pkt->ptype) { case DCERPC_PKT_REQUEST: reply = process_request_pdu(p, pkt); @@ -1595,9 +1596,7 @@ void process_complete_pdu(struct pipes_struct *p, struct ncacn_packet *pkt) /* * We assume that a pipe bind is only in one pdu. */ - if (pipe_init_outgoing_data(p)) { - reply = api_pipe_bind_req(p, pkt); - } + reply = api_pipe_bind_req(p, pkt); break; case DCERPC_PKT_BIND_ACK: @@ -1612,9 +1611,7 @@ void process_complete_pdu(struct pipes_struct *p, struct ncacn_packet *pkt) /* * We assume that a pipe bind is only in one pdu. */ - if (pipe_init_outgoing_data(p)) { - reply = api_pipe_alter_context(p, pkt); - } + reply = api_pipe_alter_context(p, pkt); break; case DCERPC_PKT_ALTER_RESP: @@ -1626,9 +1623,7 @@ void process_complete_pdu(struct pipes_struct *p, struct ncacn_packet *pkt) /* * The third packet in an auth exchange. */ - if (pipe_init_outgoing_data(p)) { - reply = api_pipe_bind_auth3(p, pkt); - } + reply = api_pipe_bind_auth3(p, pkt); break; case DCERPC_PKT_SHUTDOWN: @@ -1676,6 +1671,7 @@ void process_complete_pdu(struct pipes_struct *p, struct ncacn_packet *pkt) break; } +done: if (!reply) { DEBUG(3,("DCE/RPC fault sent!")); set_incoming_fault(p); -- 2.11.4.GIT