[PATCH bpf-next v3 1/4] bpf: sockmap: enable map_update_elem from bpf_iter
From: Lorenz Bauer <hidden>
Date: 2020-09-29 09:31:23
Also in:
bpf, lkml
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [l7 framework] (sockmap), networking [general], networking [sockets], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, John Fastabend, Jakub Sitnicki, Jiayuan Chen, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
Allow passing a pointer to a BTF struct sock_common* when updating a sockmap or sockhash. Since BTF pointers can fault and therefore be NULL at runtime we need to add an additional !sk check to sock_map_update_elem. Since we may be passed a request or timewait socket we also need to check sk_fullsock. Doing this allows calling map_update_elem on sockmap from bpf_iter context, which uses BTF pointers. Signed-off-by: Lorenz Bauer <redacted> Acked-by: Martin KaFai Lau <redacted> --- kernel/bpf/verifier.c | 2 +- net/core/sock_map.c | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b25ba989c2dc..cc9c90d74dc1 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -3943,7 +3943,7 @@ static int resolve_map_arg_type(struct bpf_verifier_env *env, case BPF_MAP_TYPE_SOCKMAP: case BPF_MAP_TYPE_SOCKHASH: if (*arg_type == ARG_PTR_TO_MAP_VALUE) { - *arg_type = ARG_PTR_TO_SOCKET; + *arg_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON; } else { verbose(env, "invalid arg_type for sockmap/sockhash\n"); return -EINVAL;
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index e1f05e3fa1d0..08bc86f51593 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c@@ -610,6 +610,9 @@ static int sock_map_update_elem(struct bpf_map *map, void *key, struct sock *sk = (struct sock *)value; int ret; + if (unlikely(!sk || !sk_fullsock(sk))) + return -EINVAL; + if (!sock_map_sk_is_suitable(sk)) return -EOPNOTSUPP;
--
2.25.1