From 6550f2dddfab02a5b948369eeeaedfbc4ae3cc16 Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Mon, 28 Sep 2020 10:08:02 +0100 Subject: [PATCH] bpf: sockmap: Enable map_update_elem from bpf_iter 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 Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200928090805.23343-2-lmb@cloudflare.com --- 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; -- 2.11.0