dsdb: Always store and return the userParameters as a array of LE 16-bit values

This is not allowed to be odd length, as otherwise we can not send it over the SAMR transport correctly.

Allocating one byte less memory than required causes malloc() heap corruption
and then a crash or lockup of the SAMR server.

Andrew Bartlett

Bug: https://bugzilla.samba.org/show_bug.cgi?id=10130
Change-Id: I5c0c531c1d660141e07f884a4789ebe11c1716f6
Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>

diff --git a/source3/passdb/pdb_samba_dsdb.c b/source3/passdb/pdb_samba_dsdb.c
index 7e7468dcdb10fddc70b80c45870a8a090ef8fd3f..b04e7b230a791f09d75cda238229066ea33e0120 100644 (file)
--- a/source3/passdb/pdb_samba_dsdb.c
+++ b/source3/passdb/pdb_samba_dsdb.c
@@ -259,9 +259,13 @@ static NTSTATUS pdb_samba_dsdb_init_sam_from_priv(struct pdb_methods *m,
                pdb_set_workstations(sam, str, PDB_SET);
        }
 
-       str = ldb_msg_find_attr_as_string(msg, "userParameters",
-                                           NULL);
-       if (str != NULL) {
+       blob = ldb_msg_find_ldb_val(msg, "userParameters");
+       if (blob != NULL) {
+               str = base64_encode_data_blob(frame, *blob);
+               if (str == NULL) {
+                       DEBUG(0, ("base64_encode_data_blob() failed\n"));
+                       goto fail;
+               }
                pdb_set_munged_dial(sam, str, PDB_SET);
        }
 
@@ -555,8 +559,25 @@ static int pdb_samba_dsdb_replace_by_sam(struct pdb_samba_dsdb_state *state,
 
        /* This will need work, it is actually a UTF8 'string' with internal NULLs, to handle TS parameters */
        if (need_update(sam, PDB_MUNGEDDIAL)) {
-               ret |= ldb_msg_add_string(msg, "userParameters",
-                                         pdb_get_munged_dial(sam));
+               const char *base64_munged_dial = NULL;
+
+               base64_munged_dial = pdb_get_munged_dial(sam);
+               if (base64_munged_dial != NULL && strlen(base64_munged_dial) > 0) {
+                       struct ldb_val blob;
+
+                       blob = base64_decode_data_blob_talloc(msg,
+                                                       base64_munged_dial);
+                       if (blob.data == NULL) {
+                               DEBUG(0, ("Failed to decode userParameters from "
+                                         "munged dialback string[%s] for %s\n",
+                                         base64_munged_dial,
+                                         ldb_dn_get_linearized(msg->dn)));
+                               talloc_free(frame);
+                               return LDB_ERR_INVALID_ATTRIBUTE_SYNTAX;
+                       }
+                       ret |= ldb_msg_add_steal_value(msg, "userParameters",
+                                                      &blob);
+               }
        }
 
        if (need_update(sam, PDB_COUNTRY_CODE)) {

diff --git a/source4/dsdb/common/util.c b/source4/dsdb/common/util.c
index 2aa6a6ccf774f7efa0c489d91e69477e73d45d98..18f16f698149e736232e51a060d5b513015ea730 100644 (file)
--- a/source4/dsdb/common/util.c
+++ b/source4/dsdb/common/util.c
@@ -708,27 +708,42 @@ uint32_t samdb_result_acct_flags(struct ldb_message *msg, const char *attr)
        return acct_flags;
 }
 
-struct lsa_BinaryString samdb_result_parameters(TALLOC_CTX *mem_ctx,
-                                               struct ldb_message *msg,
-                                               const char *attr)
+NTSTATUS samdb_result_parameters(TALLOC_CTX *mem_ctx,
+                                struct ldb_message *msg,
+                                const char *attr,
+                                struct lsa_BinaryString *s)
 {
-       struct lsa_BinaryString s;
+       int i;
        const struct ldb_val *val = ldb_msg_find_ldb_val(msg, attr);
 
-       ZERO_STRUCT(s);
+       ZERO_STRUCTP(s);
 
        if (!val) {
-               return s;
+               return NT_STATUS_OK;
+       }
+
+       if ((val->length % 2) != 0) {
+               /*
+                * If the on-disk data is not even in length, we know
+                * it is corrupt, and can not be safely pushed.  We
+                * would either truncate, send either a un-initilaised
+                * byte or send a forced zero byte
+                */
+               return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }
 
-       s.array = talloc_array(mem_ctx, uint16_t, val->length/2);
-       if (!s.array) {
-               return s;
+       s->array = talloc_array(mem_ctx, uint16_t, val->length/2);
+       if (!s->array) {
+               return NT_STATUS_NO_MEMORY;
        }
-       s.length = s.size = val->length;
-       memcpy(s.array, val->data, val->length);
+       s->length = s->size = val->length;
 
-       return s;
+       /* The on-disk format is the 'network' format, being UTF16LE (sort of) */
+       for (i = 0; i < s->length / 2; i++) {
+               s->array[i] = SVAL(val->data, i * 2);
+       }
+
+       return NT_STATUS_OK;
 }
 
 /* Find an attribute, with a particular value */
@@ -1036,10 +1051,26 @@ int samdb_msg_add_logon_hours(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx,
 int samdb_msg_add_parameters(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
                             const char *attr_name, struct lsa_BinaryString *parameters)
 {
+       int i;
        struct ldb_val val;
+       if ((parameters->length % 2) != 0) {
+               return LDB_ERR_INVALID_ATTRIBUTE_SYNTAX;
+       }
+
+       val.data = talloc_array(mem_ctx, uint8_t, parameters->length);
+       if (val.data == NULL) {
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
        val.length = parameters->length;
-       val.data = (uint8_t *)parameters->array;
-       return ldb_msg_add_value(msg, attr_name, &val, NULL);
+       for (i = 0; i < parameters->length / 2; i++) {
+               /*
+                * The on-disk format needs to be in the 'network'
+                * format, parmeters->array is a uint16_t array of
+                * length parameters->length / 2
+                */
+               SSVAL(val.data, i * 2, parameters->array[i]);
+       }
+       return ldb_msg_add_steal_value(msg, attr_name, &val);
 }
 
 /*

diff --git a/source4/rpc_server/samr/dcesrv_samr.c b/source4/rpc_server/samr/dcesrv_samr.c
index eacbe7da7b46797a03ae013268a99c03e5e8aed9..c0bec437c2c9fccb43d8896cd8cdce2fdf42d5b8 100644 (file)
--- a/source4/rpc_server/samr/dcesrv_samr.c
+++ b/source4/rpc_server/samr/dcesrv_samr.c
@@ -64,8 +64,6 @@
        info->field = samdb_result_logon_hours(mem_ctx, msg, attr);
 #define QUERY_AFLAGS(msg, field, attr) \
        info->field = samdb_result_acct_flags(msg, attr);
-#define QUERY_PARAMETERS(msg, field, attr) \
-       info->field = samdb_result_parameters(mem_ctx, msg, attr);
 
 
 /* these are used to make the Set[User|Group]Info code easier to follow */
@@ -2700,6 +2698,8 @@ static NTSTATUS dcesrv_samr_QueryUserInfo(struct dcesrv_call_state *dce_call, TA
        const char * const *attrs = NULL;
        union samr_UserInfo *info;
 
+       NTSTATUS status;
+
        *r->out.info = NULL;
 
        DCESRV_PULL_HANDLE(h, r->in.user_handle, SAMR_HANDLE_USER);
@@ -3048,7 +3048,11 @@ static NTSTATUS dcesrv_samr_QueryUserInfo(struct dcesrv_call_state *dce_call, TA
                break;
 
        case 20:
-               QUERY_PARAMETERS(msg, info20.parameters,    "userParameters");
+               status = samdb_result_parameters(mem_ctx, msg, "userParameters", &info->info20.parameters);
+               if (!NT_STATUS_IS_OK(status)) {
+                       talloc_free(info);
+                       return status;
+               }
                break;
 
        case 21:
@@ -3067,7 +3071,12 @@ static NTSTATUS dcesrv_samr_QueryUserInfo(struct dcesrv_call_state *dce_call, TA
                QUERY_STRING(msg, info21.description,          "description");
                QUERY_STRING(msg, info21.workstations,         "userWorkstations");
                QUERY_STRING(msg, info21.comment,              "comment");
-               QUERY_PARAMETERS(msg, info21.parameters,       "userParameters");
+               status = samdb_result_parameters(mem_ctx, msg, "userParameters", &info->info21.parameters);
+               if (!NT_STATUS_IS_OK(status)) {
+                       talloc_free(info);
+                       return status;
+               }
+
                QUERY_RID   (msg, info21.rid,                  "objectSid");
                QUERY_UINT  (msg, info21.primary_gid,          "primaryGroupID");
                QUERY_AFLAGS(msg, info21.acct_flags,           "msDS-User-Account-Control-Computed");