From: Stefan Metzmacher <metze@samba.org>
Date: Fri, 7 Feb 2025 12:57:45 +0000 (+0100)
Subject: winbindd: use struct winbindd_domain_ref in struct winbindd_list_users_domstate
X-Git-Tag: tevent-0.17.0~836
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c325b9ce6fb6d46fa41c19c9cf0b5ce627f21c4b;p=thirdparty%2Fsamba.git

winbindd: use struct winbindd_domain_ref in struct winbindd_list_users_domstate

In the next commits it will be possible that
struct winbindd_domain instances become stale
because trusted domains were reloaded.

That means aync state structure should not use
pointers to 'struct winbindd_domain' as they
can become stale!

Instead they should use 'struct winbindd_domain_ref domain'
in the async state and use winbindd_domain_ref_set/get()
to manage the 'struct winbindd_domain' pointer.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
---

diff --git a/source3/winbindd/winbindd_list_users.c b/source3/winbindd/winbindd_list_users.c
index 8630672c323..298917e8df8 100644
--- a/source3/winbindd/winbindd_list_users.c
+++ b/source3/winbindd/winbindd_list_users.c
@@ -24,7 +24,7 @@
 
 struct winbindd_list_users_domstate {
 	struct tevent_req *subreq;
-	struct winbindd_domain *domain;
+	struct winbindd_domain_ref domain;
 	char *users;
 };
 
@@ -85,21 +85,31 @@ struct tevent_req *winbindd_list_users_send(TALLOC_CTX *mem_ctx,
 	}
 
 	if (request->domain_name[0] != '\0') {
-		state->domains[0].domain = find_domain_from_name_noinit(
+		domain = find_domain_from_name_noinit(
 			request->domain_name);
-		if (state->domains[0].domain == NULL) {
+		if (domain == NULL) {
 			tevent_req_nterror(req, NT_STATUS_NO_SUCH_DOMAIN);
 			return tevent_req_post(req, ev);
 		}
+		winbindd_domain_ref_set(&state->domains[0].domain, domain);
 	} else {
 		i = 0;
 		for (domain = domain_list(); domain; domain = domain->next) {
-			state->domains[i++].domain = domain;
+			winbindd_domain_ref_set(&state->domains[i++].domain,
+						domain);
 		}
 	}
 
 	for (i=0; i<state->num_domains; i++) {
 		struct winbindd_list_users_domstate *d = &state->domains[i];
+		bool valid;
+
+		/*
+		 * We set the ref a few lines above, it must be valid!
+		 */
+		valid = winbindd_domain_ref_get(&d->domain, &domain);
+		SMB_ASSERT(valid);
+
 		/*
 		 * Use "state" as a talloc memory context since it has type
 		 * "struct tevent_req". This is needed to make tevent call depth
@@ -107,7 +117,7 @@ struct tevent_req *winbindd_list_users_send(TALLOC_CTX *mem_ctx,
 		 * After calling wb_query_user_list_send(), re-parent back to
 		 * "state->domains" to make TALLOC_FREE(state->domains) working.
 		 */
-		d->subreq = wb_query_user_list_send(state, ev, d->domain);
+		d->subreq = wb_query_user_list_send(state, ev, domain);
 		d->subreq = talloc_reparent(state, state->domains, d->subreq);
 		if (tevent_req_nomem(d->subreq, req)) {
 			TALLOC_FREE(state->domains);