net-snmp: CVE-2022-44792 & CVE-2022-44793 Fix NULL Pointer Exception

Upstream-Status: Backport from https://github.com/net-snmp/net-snmp/commit/be804106fd0771a7d05236cff36e199af077af57

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

2 files changed, 117 insertions, 0 deletions

diff --git a/meta-networking/recipes-protocols/net-snmp/net-snmp/CVE-2022-44792-CVE-2022-44793.patch b/meta-networking/recipes-protocols/net-snmp/net-snmp/CVE-2022-44792-CVE-2022-44793.patch
new file mode 100644
index 0000000000..ce7e3422ed
--- /dev/null
+++ b/meta-networking/recipes-protocols/net-snmp/net-snmp/CVE-2022-44792-CVE-2022-44793.patch
@@ -0,0 +1,116 @@
+From 4589352dac3ae111c7621298cf231742209efd9b Mon Sep 17 00:00:00 2001
+From: Bill Fenner <fenner@gmail.com>
+Date: Fri, 25 Nov 2022 08:41:24 -0800
+Subject: [PATCH ] snmp_agent: disallow SET with NULL varbind
+
+Upstream-Status: Backport [https://github.com/net-snmp/net-snmp/commit/be804106fd0771a7d05236cff36e199af077af57]
+CVE: CVE-2022-44792 & CVE-2022-44793
+Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
+---
+ agent/snmp_agent.c                            | 32 +++++++++++++++++++
+ apps/snmpset.c                                |  1 +
+ .../default/T0142snmpv2csetnull_simple        | 31 ++++++++++++++++++
+ 3 files changed, 64 insertions(+)
+ create mode 100644 testing/fulltests/default/T0142snmpv2csetnull_simple
+
+diff --git a/agent/snmp_agent.c b/agent/snmp_agent.c
+index 3376357..f51c252 100644
+--- a/agent/snmp_agent.c
++++ b/agent/snmp_agent.c
+@@ -3719,12 +3719,44 @@ netsnmp_handle_request(netsnmp_agent_session *asp, int status)
+     return 1;
+ }
+ 
++static int
++check_set_pdu_for_null_varbind(netsnmp_agent_session *asp)
++{
++    int i;
++    netsnmp_variable_list *v = NULL;
++
++    for (i = 1, v = asp->pdu->variables; v != NULL; i++, v = v->next_variable) {
++	if (v->type == ASN_NULL) {
++	    /*
++	     * Protect SET implementations that do not protect themselves
++	     * against wrong type.
++	     */
++	    DEBUGMSGTL(("snmp_agent", "disallowing SET with NULL var for varbind %d\n", i));
++	    asp->index = i;
++	    return SNMP_ERR_WRONGTYPE;
++	}
++    }
++    return SNMP_ERR_NOERROR;
++}
++
+ int
+ handle_pdu(netsnmp_agent_session *asp)
+ {
+     int             status, inclusives = 0;
+     netsnmp_variable_list *v = NULL;
+ 
++#ifndef NETSNMP_NO_WRITE_SUPPORT
++    /*
++     * Check for ASN_NULL in SET request
++     */
++    if (asp->pdu->command == SNMP_MSG_SET) {
++	status = check_set_pdu_for_null_varbind(asp);
++	if (status != SNMP_ERR_NOERROR) {
++	    return status;
++	}
++    }
++#endif /* NETSNMP_NO_WRITE_SUPPORT */
++
+     /*
+      * for illegal requests, mark all nodes as ASN_NULL 
+      */
+diff --git a/apps/snmpset.c b/apps/snmpset.c
+index 50f33db..387a51d 100644
+--- a/apps/snmpset.c
++++ b/apps/snmpset.c
+@@ -182,6 +182,7 @@ main(int argc, char *argv[])
+             case 'x':
+             case 'd':
+             case 'b':
++            case 'n': /* undocumented */
+ #ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
+             case 'I':
+             case 'U':
+diff --git a/testing/fulltests/default/T0142snmpv2csetnull_simple b/testing/fulltests/default/T0142snmpv2csetnull_simple
+new file mode 100644
+index 0000000..0f1b8f3
+--- /dev/null
++++ b/testing/fulltests/default/T0142snmpv2csetnull_simple
+@@ -0,0 +1,31 @@
++#!/bin/sh
++
++. ../support/simple_eval_tools.sh
++
++HEADER SNMPv2c set of system.sysContact.0 with NULL varbind
++
++SKIPIF NETSNMP_DISABLE_SET_SUPPORT
++SKIPIF NETSNMP_NO_WRITE_SUPPORT
++SKIPIF NETSNMP_DISABLE_SNMPV2C
++SKIPIFNOT USING_MIBII_SYSTEM_MIB_MODULE
++
++#
++# Begin test
++#
++
++# standard V2C configuration: testcomunnity
++snmp_write_access='all'
++. ./Sv2cconfig
++STARTAGENT
++
++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"
++
++CHECK ".1.3.6.1.2.1.1.4.0 = STRING:"
++
++CAPTURE "snmpset -On $SNMP_FLAGS -c testcommunity -v 2c $SNMP_TRANSPORT_SPEC:$SNMP_TEST_DEST$SNMP_SNMPD_PORT .1.3.6.1.2.1.1.4.0 n x"
++
++CHECK "Reason: wrongType"
++
++STOPAGENT
++
++FINISHED
+-- 
+2.25.1
+
diff --git a/meta-networking/recipes-protocols/net-snmp/net-snmp_5.9.3.bb b/meta-networking/recipes-protocols/net-snmp/net-snmp_5.9.3.bb
index 7af5147566..eb8e1599fb 100644
--- a/meta-networking/recipes-protocols/net-snmp/net-snmp_5.9.3.bb
+++ b/meta-networking/recipes-protocols/net-snmp/net-snmp_5.9.3.bb
@@ -26,6 +26,7 @@ SRC_URI = "${SOURCEFORGE_MIRROR}/net-snmp/net-snmp-${PV}.tar.gz \
            file://net-snmp-fix-for-disable-des.patch \
            file://reproducibility-have-printcap.patch \
            file://0001-ac_add_search_path.m4-keep-consistent-between-32bit.patch \
+           file://CVE-2022-44792-CVE-2022-44793.patch \
            "
 SRC_URI[sha256sum] = "2097f29b7e1bf3f1300b4bae52fa2308d0bb8d5d3998dbe02f9462a413a2ef0a"