| Message ID | 20200915182959.241101-1-kafai@fb.com |
|---|---|
| State | New |
| Headers | show |
| Series | [bpf] bpf: bpf_skc_to_* casting helpers require a NULL check on sk | expand |
On 9/15/20 11:29 AM, Martin KaFai Lau wrote: > 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 <kafai@fb.com> Thanks for the fix! Acked-by: Yonghong Song <yhs@fb.com>
On Tue, Sep 15, 2020 at 11:58:01AM -0700, Yonghong Song wrote: > > > On 9/15/20 11:29 AM, Martin KaFai Lau wrote: > > 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 <kafai@fb.com> > > Thanks for the fix! > > Acked-by: Yonghong Song <yhs@fb.com> Thanks for the review. A follow up question. Is PTR_TO_BTF_ID_OR_NULL still needed?
On 9/15/20 1:04 PM, Martin KaFai Lau wrote: > On Tue, Sep 15, 2020 at 11:58:01AM -0700, Yonghong Song wrote: >> >> >> On 9/15/20 11:29 AM, Martin KaFai Lau wrote: >>> 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 <kafai@fb.com> >> >> Thanks for the fix! >> >> Acked-by: Yonghong Song <yhs@fb.com> > Thanks for the review. A follow up question. > Is PTR_TO_BTF_ID_OR_NULL still needed? I would still like to preserve PTR_TO_BTF_ID_OR_NULL vs. PTR_TO_BTF_ID difference for ctx arguments. PTR_TO_BTF_ID_OR_NULL means a NULL check is required and PTR_TO_BTF_ID means NULL check is not required.
On Tue, Sep 15, 2020 at 11:32 AM Martin KaFai Lau <kafai@fb.com> wrote: > > 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 <kafai@fb.com> Acked-by: Song Liu <songliubraving@fb.com>
On Tue, Sep 15, 2020 at 2:45 PM Song Liu <song@kernel.org> wrote: > > On Tue, Sep 15, 2020 at 11:32 AM Martin KaFai Lau <kafai@fb.com> wrote: > > > > 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 <kafai@fb.com> > > Acked-by: Song Liu <songliubraving@fb.com> Applied. Thanks
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;
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 <kafai@fb.com> --- net/core/filter.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)