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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C70BC433EF for ; Mon, 1 Nov 2021 09:27:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03F2561354 for ; Mon, 1 Nov 2021 09:27:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232284AbhKAJaB (ORCPT ); Mon, 1 Nov 2021 05:30:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:58250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232969AbhKAJ0Z (ORCPT ); Mon, 1 Nov 2021 05:26:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ACA8B60F70; Mon, 1 Nov 2021 09:22:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635758527; bh=gDkV0NOe9BGXhmQRGO1YukRLP6lPYzaaA1KpmtPouW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l55nRnTgTZEEAfVO8sddJazhfDd9z9ZnsUJD7wZkQ8LCuPn/3nlmr2ZmIIoUm0fAq cDbR4EnkTgBRtyj4drcAxfX6nrYUEkPF2/o3VnGhZRuIfVGM3ebyLM2ImBSVON9Z1c 6PpitpPuFtSYbyFZ7wVKllr0bwWee8OIHFWOb79s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xin Long , Marcelo Ricardo Leitner , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 35/35] sctp: add vtag check in sctp_sf_ootb Date: Mon, 1 Nov 2021 10:17:47 +0100 Message-Id: <20211101082459.925983111@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211101082451.430720900@linuxfoundation.org> References: <20211101082451.430720900@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xin Long [ Upstream commit 9d02831e517aa36ee6bdb453a0eb47bd49923fe3 ] sctp_sf_ootb() is called when processing DATA chunk in closed state, and many other places are also using it. The vtag in the chunk's sctphdr should be verified, otherwise, as later in chunk length check, it may send abort with the existent asoc's vtag, which can be exploited by one to cook a malicious chunk to terminate a SCTP asoc. When fails to verify the vtag from the chunk, this patch sets asoc to NULL, so that the abort will be made with the vtag from the received chunk later. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sctp/sm_statefuns.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 2995d00bd5d0..ebca069064df 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -3583,6 +3583,9 @@ enum sctp_disposition sctp_sf_ootb(struct net *net, SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); + if (asoc && !sctp_vtag_verify(chunk, asoc)) + asoc = NULL; + ch = (struct sctp_chunkhdr *)chunk->chunk_hdr; do { /* Report violation if the chunk is less then minimal */ -- 2.33.0