From: Thomas Abraham <tabraham@suse.com>
Date: Mon, 30 Jun 2025 18:03:56 +0000 (-0400)
Subject: ensure file descriptors 0-2 are in use before using libuv
X-Git-Tag: v9.21.12~17^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5cfdbeba72092e3e5f48f4b071084585efc5219f;p=thirdparty%2Fbind9.git

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
---

diff --git a/lib/isc/uv.c b/lib/isc/uv.c
index f0dcd51212d..c0361746cae 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("uv", &isc__uv_mctx);