bpf: sockmap: Require attach_bpf_fd when detaching a program

commit bb0de3131f4c60a9bf976681e0fe4d1e55c7a821 upstream.

The sockmap code currently ignores the value of attach_bpf_fd when
detaching a program. This is contrary to the usual behaviour of
checking that attach_bpf_fd represents the currently attached
program.

Ensure that attach_bpf_fd is indeed the currently attached
program. It turns out that all sockmap selftests already do this,
which indicates that this is unlikely to cause breakage.

Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200629095630.7933-5-lmb@cloudflare.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lorenz Bauer 2020-06-29 10:56:28 +01:00 • committed by Greg Kroah-Hartman
commit ca7ace8fd2
4 changed files with 71 additions and 9 deletions

View file

@ -2029,10 +2029,10 @@ static int bpf_prog_detach(const union bpf_attr *attr)
ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
break;
case BPF_SK_MSG_VERDICT:
return sock_map_get_from_fd(attr, NULL);
return sock_map_prog_detach(attr, BPF_PROG_TYPE_SK_MSG);
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
return sock_map_get_from_fd(attr, NULL);
return sock_map_prog_detach(attr, BPF_PROG_TYPE_SK_SKB);
case BPF_LIRC_MODE2:
return lirc_prog_detach(attr);
case BPF_FLOW_DISSECTOR: