[PATCH 5.11 170/254] libbpf: Use SOCK_CLOEXEC when opening the netlink socket

[Greg Kroah-Hartman]

From: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>

[ Upstream commit 58bfd95b554f1a23d01228672f86bb489bdbf4ba ]

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@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20210317115857.6536-1-memxor@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 4dd73de00b6f..d2cb28e9ef52 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;
 
-- 
2.30.1