bpf: require CAP_NET_ADMIN when using devmap

Devmap is used with XDP which requires CAP_NET_ADMIN so lets also
make CAP_NET_ADMIN required to use the map.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 920428d84da2..52e0548ba548 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -78,6 +78,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
         int err = -EINVAL;
         u64 cost;
 
+        if (!capable(CAP_NET_ADMIN))
+                return ERR_PTR(-EPERM);
+
         /* check sanity of attributes */
         if (attr->max_entries == 0 || attr->key_size != 4 ||
             attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE)