sctp: prevent too-fast association id reuse (4814326b) · Commits · 戴 / test

We use the idr subsystem and always ask for an id at or above 1. This results in a id reuse when one association is terminated while another is created. To prevent re-use, we keep track of the last id returned and ask for that id + 1 as a base for each query. We let the idr spin lock protect this base id as well. Signed-off-by:

Vlad Yasevich <vladislav.yasevich@hp.com>

net/sctp/associola.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -63,6 +63,12 @@
		static void sctp_assoc_bh_rcv(struct work_struct *work);
		static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);

		/* Keep track of the new idr low so that we don't re-use association id
		* numbers too fast. It is protected by they idr spin lock is in the
		* range of 1 - INT_MAX.
		*/
		static u32 idr_low = 1;


		/* 1st Level Abstractions. */

		@@ -1553,7 +1559,12 @@ retry:

		spin_lock_bh(&sctp_assocs_id_lock);
		error = idr_get_new_above(&sctp_assocs_id, (void *)asoc,
		1, &assoc_id);
		idr_low, &assoc_id);
		if (!error) {
		idr_low = assoc_id + 1;
		if (idr_low == INT_MAX)
		idr_low = 1;
		}
		spin_unlock_bh(&sctp_assocs_id_lock);
		if (error == -EAGAIN)
		goto retry;

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