Blame SOURCES/net-snmp-5.9-CVE-2022-44792-44793.patch

91f3ae
From 4589352dac3ae111c7621298cf231742209efd9b Mon Sep 17 00:00:00 2001
91f3ae
From: Bill Fenner <fenner@gmail.com>
91f3ae
Date: Fri, 25 Nov 2022 08:41:24 -0800
91f3ae
Subject: [PATCH 1/3] snmp_agent: disallow SET with NULL varbind
91f3ae
91f3ae
---
91f3ae
 agent/snmp_agent.c | 32 ++++++++++++++++++++++++++++++++
91f3ae
 1 file changed, 32 insertions(+)
91f3ae
91f3ae
diff --git a/agent/snmp_agent.c b/agent/snmp_agent.c
91f3ae
index 867d0c166f..3f678fe2df 100644
91f3ae
--- a/agent/snmp_agent.c
91f3ae
+++ b/agent/snmp_agent.c
91f3ae
@@ -3719,12 +3719,44 @@ netsnmp_handle_request(netsnmp_agent_session *asp, int status)
91f3ae
     return 1;
91f3ae
 }
91f3ae
 
91f3ae
+static int
91f3ae
+check_set_pdu_for_null_varbind(netsnmp_agent_session *asp)
91f3ae
+{
91f3ae
+    int i;
91f3ae
+    netsnmp_variable_list *v = NULL;
91f3ae
+
91f3ae
+    for (i = 1, v = asp->pdu->variables; v != NULL; i++, v = v->next_variable) {
91f3ae
+	if (v->type == ASN_NULL) {
91f3ae
+	    /*
91f3ae
+	     * Protect SET implementations that do not protect themselves
91f3ae
+	     * against wrong type.
91f3ae
+	     */
91f3ae
+	    DEBUGMSGTL(("snmp_agent", "disallowing SET with NULL var for varbind %d\n", i));
91f3ae
+	    asp->index = i;
91f3ae
+	    return SNMP_ERR_WRONGTYPE;
91f3ae
+	}
91f3ae
+    }
91f3ae
+    return SNMP_ERR_NOERROR;
91f3ae
+}
91f3ae
+
91f3ae
 int
91f3ae
 handle_pdu(netsnmp_agent_session *asp)
91f3ae
 {
91f3ae
     int             status, inclusives = 0;
91f3ae
     netsnmp_variable_list *v = NULL;
91f3ae
 
91f3ae
+#ifndef NETSNMP_NO_WRITE_SUPPORT
91f3ae
+    /*
91f3ae
+     * Check for ASN_NULL in SET request
91f3ae
+     */
91f3ae
+    if (asp->pdu->command == SNMP_MSG_SET) {
91f3ae
+	status = check_set_pdu_for_null_varbind(asp);
91f3ae
+	if (status != SNMP_ERR_NOERROR) {
91f3ae
+	    return status;
91f3ae
+	}
91f3ae
+    }
91f3ae
+#endif /* NETSNMP_NO_WRITE_SUPPORT */
91f3ae
+
91f3ae
     /*
91f3ae
      * for illegal requests, mark all nodes as ASN_NULL 
91f3ae
      */
91f3ae
91f3ae
From 7f4ac4051cc7fec6a5944661923acb95cec359c7 Mon Sep 17 00:00:00 2001
91f3ae
From: Bill Fenner <fenner@gmail.com>
91f3ae
Date: Fri, 25 Nov 2022 08:41:46 -0800
91f3ae
Subject: [PATCH 2/3] apps: snmpset: allow SET with NULL varbind for testing
91f3ae
91f3ae
---
91f3ae
 apps/snmpset.c | 1 +
91f3ae
 1 file changed, 1 insertion(+)
91f3ae
91f3ae
diff --git a/apps/snmpset.c b/apps/snmpset.c
91f3ae
index 48e14bd513..d542713e1b 100644
91f3ae
--- a/apps/snmpset.c
91f3ae
+++ b/apps/snmpset.c
91f3ae
@@ -182,6 +182,7 @@ main(int argc, char *argv[])
91f3ae
             case 'x':
91f3ae
             case 'd':
91f3ae
             case 'b':
91f3ae
+            case 'n': /* undocumented */
91f3ae
 #ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
91f3ae
             case 'I':
91f3ae
             case 'U':
91f3ae
91f3ae
From 15f9d7f7e5b90c9b419832ed8e6413feb6570d83 Mon Sep 17 00:00:00 2001
91f3ae
From: Bill Fenner <fenner@gmail.com>
91f3ae
Date: Fri, 25 Nov 2022 10:23:32 -0800
91f3ae
Subject: [PATCH 3/3] Add test for NULL varbind set
91f3ae
91f3ae
---
91f3ae
 .../default/T0142snmpv2csetnull_simple        | 31 +++++++++++++++++++
91f3ae
 1 file changed, 31 insertions(+)
91f3ae
 create mode 100644 testing/fulltests/default/T0142snmpv2csetnull_simple
91f3ae
91f3ae
diff --git a/testing/fulltests/default/T0142snmpv2csetnull_simple b/testing/fulltests/default/T0142snmpv2csetnull_simple
91f3ae
new file mode 100644
91f3ae
index 0000000000..0f1b8f386b
91f3ae
--- /dev/null
91f3ae
+++ b/testing/fulltests/default/T0142snmpv2csetnull_simple
91f3ae
@@ -0,0 +1,31 @@
91f3ae
+#!/bin/sh
91f3ae
+
91f3ae
+. ../support/simple_eval_tools.sh
91f3ae
+
91f3ae
+HEADER SNMPv2c set of system.sysContact.0 with NULL varbind
91f3ae
+
91f3ae
+SKIPIF NETSNMP_DISABLE_SET_SUPPORT
91f3ae
+SKIPIF NETSNMP_NO_WRITE_SUPPORT
91f3ae
+SKIPIF NETSNMP_DISABLE_SNMPV2C
91f3ae
+SKIPIFNOT USING_MIBII_SYSTEM_MIB_MODULE
91f3ae
+
91f3ae
+#
91f3ae
+# Begin test
91f3ae
+#
91f3ae
+
91f3ae
+# standard V2C configuration: testcomunnity
91f3ae
+snmp_write_access='all'
91f3ae
+. ./Sv2cconfig
91f3ae
+STARTAGENT
91f3ae
+
91f3ae
+CAPTURE "snmpget -On $SNMP_FLAGS -c testcommunity -v 2c $SNMP_TRANSPORT_SPEC:$SNMP_TEST_DEST$SNMP_SNMPD_PORT .1.3.6.1.2.1.1.4.0"
91f3ae
+
91f3ae
+CHECK ".1.3.6.1.2.1.1.4.0 = STRING:"
91f3ae
+
91f3ae
+CAPTURE "snmpset -On $SNMP_FLAGS -c testcommunity -v 2c $SNMP_TRANSPORT_SPEC:$SNMP_TEST_DEST$SNMP_SNMPD_PORT .1.3.6.1.2.1.1.4.0 n x"
91f3ae
+
91f3ae
+CHECK "Reason: wrongType"
91f3ae
+
91f3ae
+STOPAGENT
91f3ae
+
91f3ae
+FINISHED
91f3ae