net: prevent a NULL deref in rtnl_create_link()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: net: prevent a NULL deref in rtnl_create_link() At the time rtnl_create_link() is running, dev->netdev_ops is NULL, we must not use netdev_lock_ops() or risk a NULL deref if CONFIG_NET_SHAPER is defined. Use netif_set_group() instead of dev_set_group(). RIP: 0010:netdev_need_ops_lock include/net/netdev_lock.h:33 [inline] RIP: 0010:netdev_lock_ops include/net/netdev_lock.h:41 [inline] RIP: 0010:dev_set_group+0xc0/0x230 net/core/dev_api.c:82 Call Trace: <TASK> rtnl_create_link+0x748/0xd10 net/core/rtnetlink.c:3674 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3813 __rtnl_newlink net/core/rtnetlink.c:3940 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline]

References

• https://git.kernel.org/stable/c/8a29ae8428a5c26f0b4471c2057d9e9415c53109
• https://git.kernel.org/stable/c/feafc73f3e6ae73371777a037d41d2e31c929636