Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756683AbaGHT3y (ORCPT ); Tue, 8 Jul 2014 15:29:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54187 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755702AbaGHTIk (ORCPT ); Tue, 8 Jul 2014 15:08:40 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Vlad Yasevich" , "Daniel Borkmann" , "Xufeng Zhang" Date: Tue, 08 Jul 2014 20:01:50 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 113/125] sctp: Fix sk_ack_backlog wrap-around problem In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Xufeng Zhang [ Upstream commit d3217b15a19a4779c39b212358a5c71d725822ee ] Consider the scenario: For a TCP-style socket, while processing the COOKIE_ECHO chunk in sctp_sf_do_5_1D_ce(), after it has passed a series of sanity check, a new association would be created in sctp_unpack_cookie(), but afterwards, some processing maybe failed, and sctp_association_free() will be called to free the previously allocated association, in sctp_association_free(), sk_ack_backlog value is decremented for this socket, since the initial value for sk_ack_backlog is 0, after the decrement, it will be 65535, a wrap-around problem happens, and if we want to establish new associations afterward in the same socket, ABORT would be triggered since sctp deem the accept queue as full. Fix this issue by only decrementing sk_ack_backlog for associations in the endpoint's list. Fix-suggested-by: Neil Horman Signed-off-by: Xufeng Zhang Acked-by: Daniel Borkmann Acked-by: Vlad Yasevich Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/sctp/associola.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -389,7 +389,7 @@ void sctp_association_free(struct sctp_a /* Only real associations count against the endpoint, so * don't bother for if this is a temporary association. */ - if (!asoc->temp) { + if (!list_empty(&asoc->asocs)) { list_del(&asoc->asocs); /* Decrement the backlog value for a TCP-style listening -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/