From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] sctp: fix the panic caused by route update Date: Wed, 26 Oct 2016 17:32:48 -0400 (EDT) Message-ID: <20161026.173248.247683142442678932.davem@davemloft.net> References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-sctp@vger.kernel.org, marcelo.leitner@gmail.com, vyasevich@gmail.com, daniel@iogearbox.net To: lucien.xin@gmail.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:42326 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S942085AbcJZVcu (ORCPT ); Wed, 26 Oct 2016 17:32:50 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Xin Long Date: Mon, 24 Oct 2016 01:01:09 +0800 > Commit 7303a1475008 ("sctp: identify chunks that need to be fragmented > at IP level") made the chunk be fragmented at IP level in the next round > if it's size exceed PMTU. > > But there still is another case, PMTU can be updated if transport's dst > expires and transport's pmtu_pending is set in sctp_packet_transmit. If > the new PMTU is less than the chunk, the same issue with that commit can > be triggered. > > So we should drop this packet and let it retransmit in another round > where it would be fragmented at IP level. > > This patch is to fix it by checking the chunk size after PMTU may be > updated and dropping this packet if it's size exceed PMTU. > > Fixes: 90017accff61 ("sctp: Add GSO support") > Signed-off-by: Xin Long Applied, and queued up for -stable, thanks!