CVE-2023-34967: mdssvc: add type checking to dalloc_value_for_key()

Change the dalloc_value_for_key() function to require an additional final
argument which denotes the expected type of the value associated with a key. If
the types don't match, return NULL.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15341

Signed-off-by: Ralph Boehme <slow@samba.org>

diff --git a/source3/rpc_server/mdssvc/dalloc.c b/source3/rpc_server/mdssvc/dalloc.c
index 007702d45408d165328410305a8ab416c82cdd35..8b79b41fd97531f5484d03908ca1b664d938cecd 100644 (file)
--- a/source3/rpc_server/mdssvc/dalloc.c
+++ b/source3/rpc_server/mdssvc/dalloc.c
@@ -159,7 +159,7 @@ void *dalloc_value_for_key(const DALLOC_CTX *d, ...)
        int result = 0;
        void *p = NULL;
        va_list args;
-       const char *type;
+       const char *type = NULL;
        int elem;
        size_t array_len;
 
@@ -170,7 +170,6 @@ void *dalloc_value_for_key(const DALLOC_CTX *d, ...)
                array_len = talloc_array_length(d->dd_talloc_array);
                elem = va_arg(args, int);
                if (elem >= array_len) {
-                       va_end(args);
                        result = -1;
                        goto done;
                }
@@ -178,8 +177,6 @@ void *dalloc_value_for_key(const DALLOC_CTX *d, ...)
                type = va_arg(args, const char *);
        }
 
-       va_end(args);
-
        array_len = talloc_array_length(d->dd_talloc_array);
 
        for (elem = 0; elem + 1 < array_len; elem += 2) {
@@ -192,8 +189,17 @@ void *dalloc_value_for_key(const DALLOC_CTX *d, ...)
                        break;
                }
        }
+       if (p == NULL) {
+               goto done;
+       }
+
+       type = va_arg(args, const char *);
+       if (strcmp(talloc_get_name(p), type) != 0) {
+               p = NULL;
+       }
 
 done:
+       va_end(args);
        if (result != 0) {
                p = NULL;
        }

diff --git a/source3/rpc_server/mdssvc/mdssvc.c b/source3/rpc_server/mdssvc/mdssvc.c
index 4f1629b2b4d1d6a85861e492469cf5410237b207..02c422116947b694c660b3ae7f32dd5e71c2e1f6 100644 (file)
--- a/source3/rpc_server/mdssvc/mdssvc.c
+++ b/source3/rpc_server/mdssvc/mdssvc.c
@@ -885,7 +885,8 @@ static bool slrpc_open_query(struct mds_ctx *mds_ctx,
 
        querystring = dalloc_value_for_key(query, "DALLOC_CTX", 0,
                                           "DALLOC_CTX", 1,
-                                          "kMDQueryString");
+                                          "kMDQueryString",
+                                          "char *");
        if (querystring == NULL) {
                DEBUG(1, ("missing kMDQueryString\n"));
                goto error;
@@ -925,8 +926,11 @@ static bool slrpc_open_query(struct mds_ctx *mds_ctx,
        slq->ctx2 = *uint64p;
 
        path_scope = dalloc_value_for_key(query, "DALLOC_CTX", 0,
-                                         "DALLOC_CTX", 1, "kMDScopeArray");
+                                         "DALLOC_CTX", 1,
+                                         "kMDScopeArray",
+                                         "sl_array_t");
        if (path_scope == NULL) {
+               DBG_ERR("missing kMDScopeArray\n");
                goto error;
        }
 
@@ -947,8 +951,11 @@ static bool slrpc_open_query(struct mds_ctx *mds_ctx,
        }
 
        reqinfo = dalloc_value_for_key(query, "DALLOC_CTX", 0,
-                                      "DALLOC_CTX", 1, "kMDAttributeArray");
+                                      "DALLOC_CTX", 1,
+                                      "kMDAttributeArray",
+                                      "sl_array_t");
        if (reqinfo == NULL) {
+               DBG_ERR("missing kMDAttributeArray\n");
                goto error;
        }
 
@@ -956,7 +963,9 @@ static bool slrpc_open_query(struct mds_ctx *mds_ctx,
        DEBUG(10, ("requested attributes: %s", dalloc_dump(reqinfo, 0)));
 
        cnids = dalloc_value_for_key(query, "DALLOC_CTX", 0,
-                                    "DALLOC_CTX", 1, "kMDQueryItemArray");
+                                    "DALLOC_CTX", 1,
+                                    "kMDQueryItemArray",
+                                    "sl_array_t");
        if (cnids) {
                ok = sort_cnids(slq, cnids->ca_cnids);
                if (!ok) {