| Message ID | 20210702001123.728035-3-john.fastabend@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | potential sockmap memleak and proc stats fix | expand |
On Thu, Jul 1, 2021 at 5:12 PM John Fastabend <john.fastabend@gmail.com> wrote: > > Proc socket stats use sk_prot->inuse_idx value to record inuse sock stats. > We currently do not set this correctly from sockmap side. The result is > reading sock stats '/proc/net/sockstat' gives incorrect values. The > socket counter is incremented correctly, but because we don't set the > counter correctly when we replace sk_prot we may omit the decrement. > > Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") > Signed-off-by: John Fastabend <john.fastabend@gmail.com> > --- > net/core/sock_map.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/net/core/sock_map.c b/net/core/sock_map.c > index 60decd6420ca..016ea5460f8f 100644 > --- a/net/core/sock_map.c > +++ b/net/core/sock_map.c > @@ -222,6 +222,9 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) > struct bpf_prog *msg_parser = NULL; > struct sk_psock *psock; > int ret; > +#ifdef CONFIG_PROC_FS > + int idx; > +#endif > > /* Only sockets we can redirect into/from in BPF need to hold > * refs to parser/verdict progs and have their sk_data_ready > @@ -293,9 +296,15 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) > if (msg_parser) > psock_set_prog(&psock->progs.msg_parser, msg_parser); > > +#ifdef CONFIG_PROC_FS > + idx = sk->sk_prot->inuse_idx; > +#endif > ret = sock_map_init_proto(sk, psock); > if (ret < 0) > goto out_drop; > +#ifdef CONFIG_PROC_FS > + sk->sk_prot->inuse_idx = idx; > +#endif I think it is better to put these into sock_map_init_proto() so that sock_map_link() does not need to worry about the sk_prot details. Thanks.
Cong Wang wrote: > On Thu, Jul 1, 2021 at 5:12 PM John Fastabend <john.fastabend@gmail.com> wrote: > > > > Proc socket stats use sk_prot->inuse_idx value to record inuse sock stats. > > We currently do not set this correctly from sockmap side. The result is > > reading sock stats '/proc/net/sockstat' gives incorrect values. The > > socket counter is incremented correctly, but because we don't set the > > counter correctly when we replace sk_prot we may omit the decrement. > > > > Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") > > Signed-off-by: John Fastabend <john.fastabend@gmail.com> > > --- > > net/core/sock_map.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/net/core/sock_map.c b/net/core/sock_map.c > > index 60decd6420ca..016ea5460f8f 100644 > > --- a/net/core/sock_map.c > > +++ b/net/core/sock_map.c > > @@ -222,6 +222,9 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) > > struct bpf_prog *msg_parser = NULL; > > struct sk_psock *psock; > > int ret; > > +#ifdef CONFIG_PROC_FS > > + int idx; > > +#endif > > > > /* Only sockets we can redirect into/from in BPF need to hold > > * refs to parser/verdict progs and have their sk_data_ready > > @@ -293,9 +296,15 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) > > if (msg_parser) > > psock_set_prog(&psock->progs.msg_parser, msg_parser); > > > > +#ifdef CONFIG_PROC_FS > > + idx = sk->sk_prot->inuse_idx; > > +#endif > > ret = sock_map_init_proto(sk, psock); > > if (ret < 0) > > goto out_drop; > > +#ifdef CONFIG_PROC_FS > > + sk->sk_prot->inuse_idx = idx; > > +#endif > > I think it is better to put these into sock_map_init_proto() > so that sock_map_link() does not need to worry about the sk_prot > details. > > Thanks. Sure, that is fine.
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 60decd6420ca..016ea5460f8f 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -222,6 +222,9 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) struct bpf_prog *msg_parser = NULL; struct sk_psock *psock; int ret; +#ifdef CONFIG_PROC_FS + int idx; +#endif /* Only sockets we can redirect into/from in BPF need to hold * refs to parser/verdict progs and have their sk_data_ready @@ -293,9 +296,15 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) if (msg_parser) psock_set_prog(&psock->progs.msg_parser, msg_parser); +#ifdef CONFIG_PROC_FS + idx = sk->sk_prot->inuse_idx; +#endif ret = sock_map_init_proto(sk, psock); if (ret < 0) goto out_drop; +#ifdef CONFIG_PROC_FS + sk->sk_prot->inuse_idx = idx; +#endif write_lock_bh(&sk->sk_callback_lock); if (stream_parser && stream_verdict && !psock->saved_data_ready) {
Proc socket stats use sk_prot->inuse_idx value to record inuse sock stats. We currently do not set this correctly from sockmap side. The result is reading sock stats '/proc/net/sockstat' gives incorrect values. The socket counter is incremented correctly, but because we don't set the counter correctly when we replace sk_prot we may omit the decrement. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> --- net/core/sock_map.c | 9 +++++++++ 1 file changed, 9 insertions(+)