From 8c33dadc3e0eef1599811a55d748a0b95da0317d Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 15 Sep 2020 11:29:59 -0700 Subject: [PATCH] bpf: Bpf_skc_to_* casting helpers require a NULL check on sk The bpf_skc_to_* type casting helpers are available to BPF_PROG_TYPE_TRACING. The traced PTR_TO_BTF_ID may be NULL. For example, the skb->sk may be NULL. Thus, these casting helpers need to check "!sk" also and this patch fixes them. Fixes: 0d4fad3e57df ("bpf: Add bpf_skc_to_udp6_sock() helper") Fixes: 478cfbdf5f13 ("bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpers") Fixes: af7ec1383361 ("bpf: Add bpf_skc_to_tcp6_sock() helper") Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200915182959.241101-1-kafai@fb.com --- net/core/filter.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 2d62c25e0395..23e8ded0ec97 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -9522,7 +9522,7 @@ BPF_CALL_1(bpf_skc_to_tcp6_sock, struct sock *, sk) * trigger an explicit type generation here. */ BTF_TYPE_EMIT(struct tcp6_sock); - if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && + if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk->sk_family == AF_INET6) return (unsigned long)sk; @@ -9540,7 +9540,7 @@ const struct bpf_func_proto bpf_skc_to_tcp6_sock_proto = { BPF_CALL_1(bpf_skc_to_tcp_sock, struct sock *, sk) { - if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP) + if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP) return (unsigned long)sk; return (unsigned long)NULL; @@ -9558,12 +9558,12 @@ const struct bpf_func_proto bpf_skc_to_tcp_sock_proto = { BPF_CALL_1(bpf_skc_to_tcp_timewait_sock, struct sock *, sk) { #ifdef CONFIG_INET - if (sk->sk_prot == &tcp_prot && sk->sk_state == TCP_TIME_WAIT) + if (sk && sk->sk_prot == &tcp_prot && sk->sk_state == TCP_TIME_WAIT) return (unsigned long)sk; #endif #if IS_BUILTIN(CONFIG_IPV6) - if (sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_TIME_WAIT) + if (sk && sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_TIME_WAIT) return (unsigned long)sk; #endif @@ -9582,12 +9582,12 @@ const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto = { BPF_CALL_1(bpf_skc_to_tcp_request_sock, struct sock *, sk) { #ifdef CONFIG_INET - if (sk->sk_prot == &tcp_prot && sk->sk_state == TCP_NEW_SYN_RECV) + if (sk && sk->sk_prot == &tcp_prot && sk->sk_state == TCP_NEW_SYN_RECV) return (unsigned long)sk; #endif #if IS_BUILTIN(CONFIG_IPV6) - if (sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_NEW_SYN_RECV) + if (sk && sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_NEW_SYN_RECV) return (unsigned long)sk; #endif @@ -9609,7 +9609,7 @@ BPF_CALL_1(bpf_skc_to_udp6_sock, struct sock *, sk) * trigger an explicit type generation here. */ BTF_TYPE_EMIT(struct udp6_sock); - if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_UDP && + if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_UDP && sk->sk_type == SOCK_DGRAM && sk->sk_family == AF_INET6) return (unsigned long)sk; -- 2.11.0