CVE-2022-38023 s3:rpc_server/netlogon: make sure all _netr_LogonSamLogon*() calls go through dcesrv_netr_check_schannel()

Some checks are also required for _netr_LogonSamLogonEx().

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15240

Signed-off-by: Samuel Cabrero <scabrero@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

1 files changed, 28 insertions, 17 deletions

diff --git a/source3/rpc_server/netlogon/srv_netlog_nt.c b/source3/rpc_server/netlogon/srv_netlog_nt.c
index c00cdce8ffb..42e0eb2cea2 100644
--- a/source3/rpc_server/netlogon/srv_netlog_nt.c
+++ b/source3/rpc_server/netlogon/srv_netlog_nt.c
@@ -1630,6 +1630,11 @@ static NTSTATUS _netr_LogonSamLogon_base(struct pipes_struct *p,
 	struct auth_serversupplied_info *server_info = NULL;
 	struct auth_context *auth_context = NULL;
 	const char *fn;
+	enum dcerpc_AuthType auth_type = DCERPC_AUTH_TYPE_NONE;
+	enum dcerpc_AuthLevel auth_level = DCERPC_AUTH_LEVEL_NONE;
+	uint16_t opnum = dce_call->pkt.u.request.opnum;
+
+	dcesrv_call_auth_info(dce_call, &auth_type, &auth_level);
 
 #ifdef DEBUG_PASSWORD
 	logon = netlogon_creds_shallow_copy_logon(p->mem_ctx,
@@ -1640,15 +1645,37 @@ static NTSTATUS _netr_LogonSamLogon_base(struct pipes_struct *p,
 	}
 #endif
 
-	switch (dce_call->pkt.u.request.opnum) {
+	switch (opnum) {
 		case NDR_NETR_LOGONSAMLOGON:
 			fn = "_netr_LogonSamLogon";
+			/*
+			 * Already called netr_check_schannel() via
+			 * netr_creds_server_step_check()
+			 */
 			break;
 		case NDR_NETR_LOGONSAMLOGONWITHFLAGS:
 			fn = "_netr_LogonSamLogonWithFlags";
+			/*
+			 * Already called netr_check_schannel() via
+			 * netr_creds_server_step_check()
+			 */
 			break;
 		case NDR_NETR_LOGONSAMLOGONEX:
 			fn = "_netr_LogonSamLogonEx";
+
+			if (auth_type != DCERPC_AUTH_TYPE_SCHANNEL) {
+				return NT_STATUS_ACCESS_DENIED;
+			}
+
+			status = dcesrv_netr_check_schannel(p->dce_call,
+							    creds,
+							    auth_type,
+							    auth_level,
+							    opnum);
+			if (NT_STATUS_IS_ERR(status)) {
+				return status;
+			}
+
 			break;
 		default:
 			return NT_STATUS_INTERNAL_ERROR;
@@ -1879,10 +1906,6 @@ static NTSTATUS _netr_LogonSamLogon_base(struct pipes_struct *p,
 						r->out.validation->sam3);
 		break;
 	case 6: {
-		enum dcerpc_AuthLevel auth_level = DCERPC_AUTH_LEVEL_NONE;
-
-		dcesrv_call_auth_info(dce_call, NULL, &auth_level);
-
 		/* Only allow this if the pipe is protected. */
 		if (auth_level < DCERPC_AUTH_LEVEL_PRIVACY) {
 			DEBUG(0,("netr_Validation6: client %s not using privacy for netlogon\n",
@@ -1995,8 +2018,6 @@ NTSTATUS _netr_LogonSamLogon(struct pipes_struct *p,
 NTSTATUS _netr_LogonSamLogonEx(struct pipes_struct *p,
 			       struct netr_LogonSamLogonEx *r)
 {
-	struct dcesrv_call_state *dce_call = p->dce_call;
-	enum dcerpc_AuthType auth_type = DCERPC_AUTH_TYPE_NONE;
 	NTSTATUS status;
 	struct netlogon_creds_CredentialState *creds = NULL;
 	struct loadparm_context *lp_ctx;
@@ -2008,16 +2029,6 @@ NTSTATUS _netr_LogonSamLogonEx(struct pipes_struct *p,
 		return status;
 	}
 
-	/* Only allow this if the pipe is protected. */
-
-	dcesrv_call_auth_info(dce_call, &auth_type, NULL);
-
-	if (auth_type != DCERPC_AUTH_TYPE_SCHANNEL) {
-		DEBUG(0,("_netr_LogonSamLogonEx: client %s not using schannel for netlogon\n",
-			get_remote_machine_name() ));
-		return NT_STATUS_INVALID_PARAMETER;
-        }
-
 	lp_ctx = loadparm_init_s3(p->mem_ctx, loadparm_s3_helpers());
 	if (lp_ctx == NULL) {
 		DEBUG(0, ("loadparm_init_s3 failed\n"));