mISDN: enforce CAP_NET_RAW for raw sockets

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

Signed-off-by: Ori Nimron <orinimron123@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE-2019-17055

(cherry picked from commit b91ee4aa2a2199ba4d4650706c272985a5a32d80)
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index c6ba37df4b9d47163a1ff6485667b696c3ce98cc..dff4132b3702c62ecebe24f3ad0fa0da1ca0c049 100644 (file)
--- 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)