sctp: hold transport before we access t->asoc in sctp proc (fba4c330) · Commits · 戴 / test

Previously, before rhashtable, /proc assoc listing was done by read-locking the entire hash entry and dumping all assocs at once, so we were sure that the assoc wasn't freed because it wouldn't be possible to remove it from the hash meanwhile. Now we use rhashtable to list transports, and dump entries one by one. That is, now we have to check if the assoc is still a good one, as the transport we got may be being freed. Signed-off-by:

Xin Long <lucien.xin@gmail.com> Reviewed-by:

Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sctp/proc.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -380,6 +380,8 @@ static int sctp_assocs_seq_show(struct seq_file seq, void v)
		}

		transport = (struct sctp_transport *)v;
		if (!sctp_transport_hold(transport))
		return 0;
		assoc = transport->asoc;
		epb = &assoc->base;
		sk = epb->sk;
		@@ -412,6 +414,8 @@ static int sctp_assocs_seq_show(struct seq_file seq, void v)
		sk->sk_rcvbuf);
		seq_printf(seq, "\n");

		sctp_transport_put(transport);

		return 0;
		}

		@@ -489,6 +493,8 @@ static int sctp_remaddr_seq_show(struct seq_file seq, void v)
		}

		tsp = (struct sctp_transport *)v;
		if (!sctp_transport_hold(tsp))
		return 0;
		assoc = tsp->asoc;

		list_for_each_entry_rcu(tsp, &assoc->peer.transport_addr_list,
		@@ -544,6 +550,8 @@ static int sctp_remaddr_seq_show(struct seq_file seq, void v)
		seq_printf(seq, "\n");
		}

		sctp_transport_put(tsp);

		return 0;
		}

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