security_context_v1: set CLOEXEC for client FDs

Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/work_items/3949
(cherry picked from commit 327f000532)

include/util/fd.h

@@ -0,0 +1,8 @@
+#ifndef UTIL_FD_H
+#define UTIL_FD_H
+
+#include <stdbool.h>
+
+bool set_cloexec(int fd, bool cloexec);
+
+#endif

types/wlr_security_context_v1.c

@@ -7,6 +7,7 @@
 #include <wlr/types/wlr_security_context_v1.h>
 #include <wlr/util/log.h>
 #include "security-context-v1-protocol.h"
+#include "util/fd.h"
 
 #define SECURITY_CONTEXT_MANAGER_V1_VERSION 1
 
@@ -129,6 +130,11 @@ static int security_context_handle_listen_fd_event(int listen_fd, uint32_t mask,
 			return 0;
 		}
 
+		if (!set_cloexec(client_fd, true)) {
+			close(client_fd);
+			return 0;
+		}
+
 		struct wlr_security_context_v1_client *security_context_client =
 			calloc(1, sizeof(*security_context_client));
 		if (security_context_client == NULL) {

util/fd.c

@@ -0,0 +1,22 @@
+#include <fcntl.h>
+#include <wlr/util/log.h>
+
+#include "util/fd.h"
+
+bool set_cloexec(int fd, bool cloexec) {
+	int flags = fcntl(fd, F_GETFD);
+	if (flags == -1) {
+		wlr_log_errno(WLR_ERROR, "fcntl failed");
+		return false;
+	}
+	if (cloexec) {
+		flags = flags | FD_CLOEXEC;
+	} else {
+		flags = flags & ~FD_CLOEXEC;
+	}
+	if (fcntl(fd, F_SETFD, flags) == -1) {
+		wlr_log_errno(WLR_ERROR, "fcntl failed");
+		return false;
+	}
+	return true;
+}

util/meson.build

@@ -3,6 +3,7 @@ wlr_files += files(
 	'array.c',
 	'box.c',
 	'env.c',
+	'fd.c',
 	'global.c',
 	'log.c',
 	'matrix.c',

xwayland/server.c

@@ -16,6 +16,7 @@
 #include <wlr/xwayland.h>
 #include "config.h"
 #include "sockets.h"
+#include "util/fd.h"
 
 static void safe_close(int fd) {
 	if (fd >= 0) {

xwayland/sockets.c

@@ -14,6 +14,7 @@
 #include <unistd.h>
 #include <wlr/util/log.h>
 #include "sockets.h"
+#include "util/fd.h"
 
 static const char lock_fmt[] = "/tmp/.X%d-lock";
 static const char socket_dir[] = "/tmp/.X11-unix";
@@ -22,24 +23,6 @@ static const char socket_fmt[] = "/tmp/.X11-unix/X%d";
 static const char socket_fmt2[] = "/tmp/.X11-unix/X%d_";
 #endif
 
-bool set_cloexec(int fd, bool cloexec) {
-	int flags = fcntl(fd, F_GETFD);
-	if (flags == -1) {
-		wlr_log_errno(WLR_ERROR, "fcntl failed");
-		return false;
-	}
-	if (cloexec) {
-		flags = flags | FD_CLOEXEC;
-	} else {
-		flags = flags & ~FD_CLOEXEC;
-	}
-	if (fcntl(fd, F_SETFD, flags) == -1) {
-		wlr_log_errno(WLR_ERROR, "fcntl failed");
-		return false;
-	}
-	return true;
-}
-
 static int open_socket(struct sockaddr_un *addr, size_t path_size) {
 	int fd, rc;
 	socklen_t size = offsetof(struct sockaddr_un, sun_path) + path_size + 1;

xwayland/sockets.h

@@ -3,7 +3,6 @@
 
 #include <stdbool.h>
 
-bool set_cloexec(int fd, bool cloexec);
 void unlink_display_sockets(int display);
 int open_display_sockets(int socks[2]);