Messages in this thread | | | Date | Tue, 13 Aug 2019 11:59:48 -0700 | From | Jakub Kicinski <> | Subject | Re: general protection fault in tls_write_space |
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On Tue, 13 Aug 2019 11:30:00 -0700, John Fastabend wrote: > Jakub Kicinski wrote: > > On Tue, 13 Aug 2019 10:17:06 -0700, John Fastabend wrote: > > > > Followup of commit 95fa145479fb > > > > ("bpf: sockmap/tls, close can race with map free") > > > > > > > > --- a/net/tls/tls_main.c > > > > +++ b/net/tls/tls_main.c > > > > @@ -308,6 +308,9 @@ static void tls_sk_proto_close(struct so > > > > if (free_ctx) > > > > icsk->icsk_ulp_data = NULL; > > > > sk->sk_prot = ctx->sk_proto; > > > > + /* tls will go; restore sock callback before enabling bh */ > > > > + if (sk->sk_write_space == tls_write_space) > > > > + sk->sk_write_space = ctx->sk_write_space; > > > > write_unlock_bh(&sk->sk_callback_lock); > > > > release_sock(sk); > > > > if (ctx->tx_conf == TLS_SW) > > > > > > Hi Hillf, > > > > > > We need this patch (although slightly updated for bpf tree) do > > > you want to send it? Otherwise I can. We should only set this if > > > TX path was enabled otherwise we null it. Checking against > > > tls_write_space seems best to me as well. > > > > > > Against bpf this patch should fix it. > > > > > > diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c > > > index ce6ef56a65ef..43252a801c3f 100644 > > > --- a/net/tls/tls_main.c > > > +++ b/net/tls/tls_main.c > > > @@ -308,7 +308,8 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) > > > if (free_ctx) > > > icsk->icsk_ulp_data = NULL; > > > sk->sk_prot = ctx->sk_proto; > > > - sk->sk_write_space = ctx->sk_write_space; > > > + if (sk->sk_write_space == tls_write_space) > > > + sk->sk_write_space = ctx->sk_write_space; > > > write_unlock_bh(&sk->sk_callback_lock); > > > release_sock(sk); > > > if (ctx->tx_conf == TLS_SW) > > > > This is already in net since Friday: > > Don't we need to guard that with an > > if (sk->sk_write_space == tls_write_space) > > or something similar? Where is ctx->sk_write_space set in the rx only > case? In do_tls_setsockop_conf() we have this block > > if (tx) { > ctx->sk_write_space = sk->sk_write_space; > sk->sk_write_space = tls_write_space; > } else { > sk->sk_socket->ops = &tls_sw_proto_ops; > } > > which makes me think ctx->sk_write_space may not be set correctly in > all cases.
Ah damn, you're right I remember looking at that but then I went down the rabbit hole of trying to repro and forgot :/
Do you want to send an incremental change?
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