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authorLorenz Bauer <lmb@cloudflare.com>2020-06-29 10:56:28 +0100
committerAlexei Starovoitov <ast@kernel.org>2020-06-30 10:46:39 -0700
commitbb0de3131f4c60a9bf976681e0fe4d1e55c7a821 (patch)
tree47c55a8dc2cb7703d467da1e43f35778c192097d /net/core
parent9b2b09717e1812e450782a43ca0c2790651cf380 (diff)
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bpf: sockmap: Require attach_bpf_fd when detaching a program
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: 604326b41a6f ("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
Diffstat (limited to 'net/core')
-rw-r--r--net/core/sock_map.c50
1 files changed, 45 insertions, 5 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 58016a5c63ff..0971f17e8e54 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -77,7 +77,42 @@ int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
- ret = sock_map_prog_update(map, prog, attr->attach_type);
+ ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
+ fdput(f);
+ return ret;
+}
+
+int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
+{
+ u32 ufd = attr->target_fd;
+ struct bpf_prog *prog;
+ struct bpf_map *map;
+ 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))
+ return PTR_ERR(map);
+
+ prog = bpf_prog_get(attr->attach_bpf_fd);
+ if (IS_ERR(prog)) {
+ ret = PTR_ERR(prog);
+ goto put_map;
+ }
+
+ if (prog->type != ptype) {
+ ret = -EINVAL;
+ goto put_prog;
+ }
+
+ ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
+put_prog:
+ bpf_prog_put(prog);
+put_map:
fdput(f);
return ret;
}
@@ -1206,27 +1241,32 @@ static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
}
int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
- u32 which)
+ struct bpf_prog *old, u32 which)
{
struct sk_psock_progs *progs = sock_map_progs(map);
+ struct bpf_prog **pprog;
if (!progs)
return -EOPNOTSUPP;
switch (which) {
case BPF_SK_MSG_VERDICT:
- psock_set_prog(&progs->msg_parser, prog);
+ pprog = &progs->msg_parser;
break;
case BPF_SK_SKB_STREAM_PARSER:
- psock_set_prog(&progs->skb_parser, prog);
+ pprog = &progs->skb_parser;
break;
case BPF_SK_SKB_STREAM_VERDICT:
- psock_set_prog(&progs->skb_verdict, prog);
+ pprog = &progs->skb_verdict;
break;
default:
return -EOPNOTSUPP;
}
+ if (old)
+ return psock_replace_prog(pprog, prog, old);
+
+ psock_set_prog(pprog, prog);
return 0;
}