| Message ID | 20210712195546.423990-3-john.fastabend@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | bpf, sockmap: fix potential memory leak | expand |
On Mon, Jul 12, 2021 at 09:55 PM CEST, John Fastabend 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. > > To get the correct inuse_idx value move the core_initcall that initializes > the tcp/udp proto handlers to late_initcall. This way it is initialized > after TCP/UDP has the chance to assign the inuse_idx value from the > register protocol handler. > > Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> > Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") > Signed-off-by: John Fastabend <john.fastabend@gmail.com> > --- > net/ipv4/tcp_bpf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c > index f26916a62f25..d3e9386b493e 100644 > --- a/net/ipv4/tcp_bpf.c > +++ b/net/ipv4/tcp_bpf.c > @@ -503,7 +503,7 @@ static int __init tcp_bpf_v4_build_proto(void) > tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot); > return 0; > } > -core_initcall(tcp_bpf_v4_build_proto); > +late_initcall(tcp_bpf_v4_build_proto); > > static int tcp_bpf_assert_proto_ops(struct proto *ops) > { Respective change for udp_bpf is missing. I've posted it separately [1] to save us an iteration. Hope you don't mind. [1] https://lore.kernel.org/bpf/20210713074401.475209-1-jakub@cloudflare.com/
On Mon, Jul 12, 2021 at 12:56 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. > > To get the correct inuse_idx value move the core_initcall that initializes > the tcp/udp proto handlers to late_initcall. This way it is initialized > after TCP/UDP has the chance to assign the inuse_idx value from the > register protocol handler. > > Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> > Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") > Signed-off-by: John Fastabend <john.fastabend@gmail.com> For IPv6, I think the module is always loaded before we can trigger tcp_bpf_check_v6_needs_rebuild(). So, Reviewed-by: Cong Wang <cong.wang@bytedance.com> Thanks.
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index f26916a62f25..d3e9386b493e 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -503,7 +503,7 @@ static int __init tcp_bpf_v4_build_proto(void) tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot); return 0; } -core_initcall(tcp_bpf_v4_build_proto); +late_initcall(tcp_bpf_v4_build_proto); static int tcp_bpf_assert_proto_ops(struct proto *ops) {
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. To get the correct inuse_idx value move the core_initcall that initializes the tcp/udp proto handlers to late_initcall. This way it is initialized after TCP/UDP has the chance to assign the inuse_idx value from the register protocol handler. Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> --- net/ipv4/tcp_bpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)