Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755637AbaFLCrb (ORCPT ); Wed, 11 Jun 2014 22:47:31 -0400 Received: from mail.windriver.com ([147.11.1.11]:37111 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755430AbaFLCra (ORCPT ); Wed, 11 Jun 2014 22:47:30 -0400 From: Xufeng Zhang To: , , CC: , , Subject: [PATCH v2] sctp: Fix sk_ack_backlog wrap-around problem Date: Thu, 12 Jun 2014 10:53:36 +0800 Message-ID: <1402541616-15117-1-git-send-email-xufeng.zhang@windriver.com> X-Mailer: git-send-email 1.7.0.2 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- Change for v2: Drop the redundant test for temp suggested by Vlad Yasevich. net/sctp/associola.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 39579c3..0b99998 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -330,7 +330,7 @@ void sctp_association_free(struct sctp_association *asoc) /* 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 -- 1.7.0.2 -- 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/