From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2EEF4C282C8 for ; Mon, 28 Jan 2019 15:45:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F04FD2147A for ; Mon, 28 Jan 2019 15:45:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548690312; bh=NthfVLmFK4e51EX0vCEjH2dF1Fxphnp2dyblMH1Fims=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ziqIdjCxXE2UnFFVr2q4bptkauqMuAGlNjIWon5Vk+CVvYo+EfYWFpJILybvYV+dp tIU3Q+F7ypPi7Q5ej+SK1dhznH1+WSptnfHr6kY5wD2iB9WtE5ROGNqmxXbNP6Qr3B PDSxK8LKYEiD7qTgfoLxHAy9s4AEn1W9iR3n94aQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726926AbfA1PpK (ORCPT ); Mon, 28 Jan 2019 10:45:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:58392 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727607AbfA1PpA (ORCPT ); Mon, 28 Jan 2019 10:45:00 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7266020880; Mon, 28 Jan 2019 15:44:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548690300; bh=NthfVLmFK4e51EX0vCEjH2dF1Fxphnp2dyblMH1Fims=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pGjbNG7PiaqvpFMZ6ZR21A20A22uSkIqus503O27anpAouj8qQfANQWFstiCXSrzq 2docsWCu2gga4q6IHSy0aRFDIpTAvx4fU8w6bn1slDJXXgzYdZxaUr5xoK3RsJDAXA BSHITSt6uiSfKDwJpYc7icA+mDvISesEnIy1kgPY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "David S. Miller" , Sasha Levin , linux-sctp@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 040/304] sctp: Fix SKB list traversal in sctp_intl_store_reasm(). Date: Mon, 28 Jan 2019 10:39:17 -0500 Message-Id: <20190128154341.47195-40-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128154341.47195-1-sashal@kernel.org> References: <20190128154341.47195-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "David S. Miller" [ Upstream commit 348bbc25c40844c5efa083a3842c7f53d70a815e ] To be fully correct, an iterator has an undefined value when something like skb_queue_walk() naturally terminates. This will actually matter when SKB queues are converted over to list_head. Formalize what this code ends up doing with the current implementation. Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/sctp/stream_interleave.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c index 500449b72eca..2b499a85db0e 100644 --- a/net/sctp/stream_interleave.c +++ b/net/sctp/stream_interleave.c @@ -140,7 +140,7 @@ static void sctp_intl_store_reasm(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) { struct sctp_ulpevent *cevent; - struct sk_buff *pos; + struct sk_buff *pos, *loc; pos = skb_peek_tail(&ulpq->reasm); if (!pos) { @@ -166,23 +166,30 @@ static void sctp_intl_store_reasm(struct sctp_ulpq *ulpq, return; } + loc = NULL; skb_queue_walk(&ulpq->reasm, pos) { cevent = sctp_skb2event(pos); if (event->stream < cevent->stream || (event->stream == cevent->stream && - MID_lt(event->mid, cevent->mid))) + MID_lt(event->mid, cevent->mid))) { + loc = pos; break; - + } if (event->stream == cevent->stream && event->mid == cevent->mid && !(cevent->msg_flags & SCTP_DATA_FIRST_FRAG) && (event->msg_flags & SCTP_DATA_FIRST_FRAG || - event->fsn < cevent->fsn)) + event->fsn < cevent->fsn)) { + loc = pos; break; + } } - __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event)); + if (!loc) + __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); + else + __skb_queue_before(&ulpq->reasm, loc, sctp_event2skb(event)); } static struct sctp_ulpevent *sctp_intl_retrieve_partial( -- 2.19.1