From: Lorenz Bauer <lmb@xxxxxxxxxxxxxx> commit 9b2b09717e1812e450782a43ca0c2790651cf380 upstream. Using BPF_PROG_ATTACH on a sockmap program currently understands no flags or replace_bpf_fd, but accepts any value. Return EINVAL instead. Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> Link: https://lore.kernel.org/bpf/20200629095630.7933-4-lmb@xxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/core/sock_map.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -70,6 +70,9 @@ int sock_map_get_from_fd(const union bpf struct fd f; int ret; + if (attr->attach_flags || attr->replace_bpf_fd) + return -EINVAL; + f = fdget(ufd); map = __bpf_map_get(f); if (IS_ERR(map))