[PATCH 4/5] mISDN: enforce CAP_NET_RAW for raw sockets

[Tyler Hicks]

From: Ori Nimron <orinimron123 at gmail.com>

When creating a raw AF_ISDN socket, CAP_NET_RAW needs to be checked
first.

Signed-off-by: Ori Nimron <orinimron123 at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: David S. Miller <davem at davemloft.net>

CVE-2019-17055

(cherry picked from commit b91ee4aa2a2199ba4d4650706c272985a5a32d80)
Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
---
 drivers/isdn/mISDN/socket.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index c6ba37df4b9d..dff4132b3702 100644
--- a/drivers/isdn/mISDN/socket.c
+++ b/drivers/isdn/mISDN/socket.c
@@ -754,6 +754,8 @@ base_sock_create(struct net *net, struct socket *sock, int protocol, int kern)
 
 	if (sock->type != SOCK_RAW)
 		return -ESOCKTNOSUPPORT;
+	if (!capable(CAP_NET_RAW))
+		return -EPERM;
 
 	sk = sk_alloc(net, PF_ISDN, GFP_KERNEL, &mISDN_proto, kern);
 	if (!sk)
-- 
2.17.1