From add7cd364008128515e0b46f0cc95f7fe0fdd0db Mon Sep 17 00:00:00 2001
From: Thomas Abraham <tabraham@suse.com>
Date: Mon, 30 Jun 2025 14:03:56 -0400
Subject: [PATCH] ensure file descriptors 0-2 are in use before using libuv

libuv expects file descriptors <= STDERR_FILENO are in use. otherwise,
it may abort when closing a file descriptor it opened.

See https://github.com/libuv/libuv/pull/4559

Closes #5226

(cherry picked from commit 5cfdbeba72092e3e5f48f4b071084585efc5219f)
---
 lib/isc/uv.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/lib/isc/uv.c b/lib/isc/uv.c
index 7ad878cf7f..a7e1a727b2 100644
--- a/lib/isc/uv.c
+++ b/lib/isc/uv.c
@@ -130,6 +130,21 @@ isc__uv_free(void *ptr) {
 
 void
 isc__uv_initialize(void) {
+	/*
+	 * Ensure the first 3 file descriptors are open
+	 * otherwise, libuv may use one and trigger abort
+	 * when closing it.
+	 *
+	 * See https://github.com/libuv/libuv/pull/4559
+	 */
+	do {
+		int fd = open("/dev/null", O_RDWR, 0);
+		RUNTIME_CHECK(fd >= 0);
+		if (fd > STDERR_FILENO) {
+			close(fd);
+			break;
+		}
+	} while (true);
 #if UV_VERSION_HEX >= UV_VERSION(1, 38, 0)
 	int r;
 	isc_mem_create(&isc__uv_mctx);