Commit 8c33dadc authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

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: 0d4fad3e ("bpf: Add bpf_skc_to_udp6_sock() helper")
Fixes: 478cfbdf ("bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpers")
Fixes: af7ec138 ("bpf: Add bpf_skc_to_tcp6_sock() helper")
Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200915182959.241101-1-kafai@fb.com
parent 65dce596

net/core/filter.c

+7 −7
Original line number Diff line number Diff line
@@ -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;