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: 0d4fad3e57 ("bpf: Add bpf_skc_to_udp6_sock() helper")
Fixes: 478cfbdf5f ("bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpers")
Fixes: af7ec13833 ("bpf: Add bpf_skc_to_tcp6_sock() helper")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200915182959.241101-1-kafai@fb.com
This commit is contained in:
Martin KaFai Lau 2020-09-15 11:29:59 -07:00 committed by Alexei Starovoitov
parent 65dce596e2
commit 8c33dadc3e

View file

@ -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;