[PATCH bpf-next v2] libbpf: use SOCK_CLOEXEC when opening the netlink socket

From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: ast@kernel.org
Cc: toke@redhat.com, Kumar Kartikeya Dwivedi <memxor@gmail.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH bpf-next v2] libbpf: use SOCK_CLOEXEC when opening the netlink socket
Date: Wed, 17 Mar 2021 17:28:58 +0530	[thread overview]
Message-ID: <20210317115857.6536-1-memxor@gmail.com> (raw)

Otherwise, there exists a small window between the opening and closing
of the socket fd where it may leak into processes launched by some other
thread.

Fixes: 949abbe88436 ("libbpf: add function to setup XDP")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
Changelog:

v1 -> v2
Tag the bpf-next tree (Toke)
Add a Fixes: tag (Toke)
---
 tools/lib/bpf/netlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
index 4dd73de00..d2cb28e9e 100644
--- a/tools/lib/bpf/netlink.c
+++ b/tools/lib/bpf/netlink.c
@@ -40,7 +40,7 @@ static int libbpf_netlink_open(__u32 *nl_pid)
 	memset(&sa, 0, sizeof(sa));
 	sa.nl_family = AF_NETLINK;
 
-	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
 	if (sock < 0)
 		return -errno;
 
-- 
2.30.2

