tevent: Set FD_CLOEXEC on epoll handle

If an application using libtevent starts a new process the epoll file descriptor
is leaked to the new process if the event context is not freed explicitly. By
setting FD_CLOEXEC this is not needed anymore.

Signed-off-by: Simo Sorce <idra@samba.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/lib/tevent/tevent_epoll.c b/lib/tevent/tevent_epoll.c
index 3ab8283955..33e1d3f20f 100644
--- a/lib/tevent/tevent_epoll.c
+++ b/lib/tevent/tevent_epoll.c
@@ -78,11 +78,20 @@ static int epoll_ctx_destructor(struct epoll_event_context *epoll_ev)
 static int epoll_init_ctx(struct epoll_event_context *epoll_ev)
 {
 	epoll_ev->epoll_fd = epoll_create(64);
-	epoll_ev->pid = getpid();
-	talloc_set_destructor(epoll_ev, epoll_ctx_destructor);
 	if (epoll_ev->epoll_fd == -1) {
+		tevent_debug(epoll_ev->ev, TEVENT_DEBUG_FATAL,
+			     "Failed to create epoll handle.\n");
 		return -1;
 	}
+
+	if (!ev_set_close_on_exec(epoll_ev->epoll_fd)) {
+		tevent_debug(epoll_ev->ev, TEVENT_DEBUG_WARNING,
+			     "Failed to set close-on-exec, file descriptor may be leaked to children.\n");
+	}
+
+	epoll_ev->pid = getpid();
+	talloc_set_destructor(epoll_ev, epoll_ctx_destructor);
+
 	return 0;
 }
 
@@ -108,6 +117,12 @@ static void epoll_check_reopen(struct epoll_event_context *epoll_ev)
 			     "Failed to recreate epoll handle after fork\n");
 		return;
 	}
+
+	if (!ev_set_close_on_exec(epoll_ev->epoll_fd)) {
+		tevent_debug(epoll_ev->ev, TEVENT_DEBUG_WARNING,
+			     "Failed to set close-on-exec, file descriptor may be leaked to children.\n");
+	}
+
 	epoll_ev->pid = getpid();
 	for (fde=epoll_ev->ev->fd_events;fde;fde=fde->next) {
 		epoll_add_event(epoll_ev, fde);