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samba-mirror/lib/fuzzing/fuzz_ldap_decode.c
Gary Lockyer 3149ea0a8a CVE-2020-10704: libcli ldap_message: Add search size limits to ldap_decode
Add search request size limits to ldap_decode calls.

The ldap server uses the smb.conf variable
"ldap max search request size" which defaults to 250Kb.
For cldap the limit is hard coded as 4096.

Credit to OSS-Fuzz

REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20454
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14334

Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
2020-05-04 02:59:32 +00:00

67 lines
1.6 KiB
C

/*
Fuzzing for ldap_decode.
Copyright (C) Michael Hanselmann 2019
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "fuzzing/fuzzing.h"
#include "lib/util/asn1.h"
#include "libcli/ldap/ldap_message.h"
#include "libcli/ldap/ldap_proto.h"
int LLVMFuzzerInitialize(int *argc, char ***argv)
{
return 0;
}
int LLVMFuzzerTestOneInput(uint8_t *buf, size_t len)
{
TALLOC_CTX *mem_ctx = talloc_init(__FUNCTION__);
struct asn1_data *asn1;
struct ldap_message *ldap_msg;
struct ldap_request_limits limits = {
/*
* The default size is currently 256000 bytes
*/
.max_search_size = 256000
};
NTSTATUS status;
/*
* Need to limit the max parse tree depth to 250 to prevent
* ASAN detecting stack overflows.
*/
asn1 = asn1_init(mem_ctx, 250);
if (!asn1) {
goto out;
}
asn1_load_nocopy(asn1, buf, len);
ldap_msg = talloc(mem_ctx, struct ldap_message);
if (!ldap_msg) {
goto out;
}
status = ldap_decode(
asn1, &limits, samba_ldap_control_handlers(), ldap_msg);
out:
talloc_free(mem_ctx);
return 0;
}