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156 lines
6.3 KiB
156 lines
6.3 KiB
7 years ago
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953926 - snmptrapd crash "buffer overflow detected" at fortify_fail.c
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commit 40938a62619590b4ea071ae85baa2f42a0b7fcb2
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Author: Jan Safranek <jsafranek@users.sourceforge.net>
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Date: Mon Apr 22 15:00:00 2013 +0200
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Check if 'asn_parse_* ' actually succeeded.
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If not, discard the packet instead of using wrong data.
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diff --git a/snmplib/snmp_api.c b/snmplib/snmp_api.c
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index e5c45d9..0842842 100644
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--- a/snmplib/snmp_api.c
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+++ b/snmplib/snmp_api.c
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@@ -4709,9 +4709,11 @@ snmp_pdu_parse(netsnmp_pdu *pdu, u_char * data, size_t * length)
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case ASN_INTEGER:
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vp->val.integer = (long *) vp->buf;
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vp->val_len = sizeof(long);
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- asn_parse_int(var_val, &len, &vp->type,
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+ data = asn_parse_int(var_val, &len, &vp->type,
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(long *) vp->val.integer,
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sizeof(*vp->val.integer));
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+ if (!data)
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+ return -1;
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break;
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case ASN_COUNTER:
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case ASN_GAUGE:
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@@ -4719,9 +4721,11 @@ snmp_pdu_parse(netsnmp_pdu *pdu, u_char * data, size_t * length)
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case ASN_UINTEGER:
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vp->val.integer = (long *) vp->buf;
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vp->val_len = sizeof(u_long);
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- asn_parse_unsigned_int(var_val, &len, &vp->type,
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+ data = asn_parse_unsigned_int(var_val, &len, &vp->type,
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(u_long *) vp->val.integer,
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vp->val_len);
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+ if (!data)
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+ return -1;
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break;
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#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
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case ASN_OPAQUE_COUNTER64:
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@@ -4730,34 +4734,45 @@ snmp_pdu_parse(netsnmp_pdu *pdu, u_char * data, size_t * length)
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case ASN_COUNTER64:
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vp->val.counter64 = (struct counter64 *) vp->buf;
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vp->val_len = sizeof(struct counter64);
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- asn_parse_unsigned_int64(var_val, &len, &vp->type,
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+ data = asn_parse_unsigned_int64(var_val, &len, &vp->type,
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(struct counter64 *) vp->val.
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counter64, vp->val_len);
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+ if (!data)
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+ return -1;
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break;
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#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
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case ASN_OPAQUE_FLOAT:
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vp->val.floatVal = (float *) vp->buf;
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vp->val_len = sizeof(float);
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- asn_parse_float(var_val, &len, &vp->type,
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+ data = asn_parse_float(var_val, &len, &vp->type,
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vp->val.floatVal, vp->val_len);
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+ if (!data)
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+ return -1;
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break;
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case ASN_OPAQUE_DOUBLE:
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vp->val.doubleVal = (double *) vp->buf;
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vp->val_len = sizeof(double);
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- asn_parse_double(var_val, &len, &vp->type,
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+ data = asn_parse_double(var_val, &len, &vp->type,
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vp->val.doubleVal, vp->val_len);
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+ if (!data)
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+ return -1;
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break;
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case ASN_OPAQUE_I64:
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vp->val.counter64 = (struct counter64 *) vp->buf;
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vp->val_len = sizeof(struct counter64);
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- asn_parse_signed_int64(var_val, &len, &vp->type,
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+ data = asn_parse_signed_int64(var_val, &len, &vp->type,
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(struct counter64 *) vp->val.counter64,
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sizeof(*vp->val.counter64));
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+ if (!data)
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+ return -1;
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break;
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#endif /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */
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- case ASN_OCTET_STR:
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case ASN_IPADDRESS:
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+ if (vp->val_len != 4)
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+ return -1;
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+ /* fallthrough */
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+ case ASN_OCTET_STR:
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case ASN_OPAQUE:
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case ASN_NSAP:
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if (vp->val_len < sizeof(vp->buf)) {
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@@ -4768,12 +4783,16 @@ snmp_pdu_parse(netsnmp_pdu *pdu, u_char * data, size_t * length)
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if (vp->val.string == NULL) {
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return -1;
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}
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- asn_parse_string(var_val, &len, &vp->type, vp->val.string,
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+ data = asn_parse_string(var_val, &len, &vp->type, vp->val.string,
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&vp->val_len);
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+ if (!data)
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+ return -1;
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break;
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case ASN_OBJECT_ID:
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vp->val_len = MAX_OID_LEN;
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- asn_parse_objid(var_val, &len, &vp->type, objid, &vp->val_len);
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+ data = asn_parse_objid(var_val, &len, &vp->type, objid, &vp->val_len);
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+ if (!data)
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+ return -1;
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vp->val_len *= sizeof(oid);
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vp->val.objid = (oid *) malloc(vp->val_len);
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if (vp->val.objid == NULL) {
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@@ -4791,8 +4810,10 @@ snmp_pdu_parse(netsnmp_pdu *pdu, u_char * data, size_t * length)
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if (vp->val.bitstring == NULL) {
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return -1;
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}
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- asn_parse_bitstring(var_val, &len, &vp->type,
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+ data = asn_parse_bitstring(var_val, &len, &vp->type,
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vp->val.bitstring, &vp->val_len);
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+ if (!data)
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+ return -1;
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break;
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default:
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snmp_log(LOG_ERR, "bad type returned (%x)\n", vp->type);
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commit aa4fb949012d7c022a436992ac203c065fd7420a
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Author: Jan Safranek <jsafranek@users.sourceforge.net>
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Date: Mon Apr 22 14:58:41 2013 +0200
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Integer values encoded in BER must have at least one character.
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If asn_length == 0, we would read the first byte of the next varbind on next line:
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if (*bufp & 0x80)
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-> reading past the buffer if there is no such variable -> sigsegv.
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diff --git a/snmplib/asn1.c b/snmplib/asn1.c
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index 1af7787..5de6b75 100644
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--- a/snmplib/asn1.c
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+++ b/snmplib/asn1.c
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@@ -510,7 +510,7 @@ asn_parse_int(u_char * data,
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(errpre, bufp, data, asn_length, *datalength))
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return NULL;
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- if ((size_t) asn_length > intsize) {
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+ if ((size_t) asn_length > intsize || (int) asn_length == 0) {
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_asn_length_err(errpre, (size_t) asn_length, intsize);
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return NULL;
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}
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@@ -582,7 +582,7 @@ asn_parse_unsigned_int(u_char * data,
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(errpre, bufp, data, asn_length, *datalength))
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return NULL;
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- if ((asn_length > (intsize + 1)) ||
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+ if (((int) asn_length > (intsize + 1)) || ((int) asn_length == 0) ||
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((asn_length == intsize + 1) && *bufp != 0x00)) {
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_asn_length_err(errpre, (size_t) asn_length, intsize);
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return NULL;
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