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=-10.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 75B0BC43387 for ; Mon, 7 Jan 2019 13:10:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C2222089F for ; Mon, 7 Jan 2019 13:10:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546866616; bh=uglj+PnscaOaYix1LjFhrx1w6YzViYzSmjPWBGe+jbg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=d4gSi+G7NaN28hjFQCbUwxHFaz//XylMQKRhinIHLZi2PHbQLotrMOXgZz1Z4z0Lv dg/Bu5v7vMmjjLaa2pkxNE+LinR8xYeoFzUSjt/G9NR3pmIE/xVc/oLHE7jPI0EeRA m9LxiC0SXfptou1nhCZPMvmq8LdAQ6/w6Ar/JNdI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732004AbfAGNKP (ORCPT ); Mon, 7 Jan 2019 08:10:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:56166 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731762AbfAGNJH (ORCPT ); Mon, 7 Jan 2019 08:09:07 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4B7B72089F; Mon, 7 Jan 2019 13:09:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546866546; bh=uglj+PnscaOaYix1LjFhrx1w6YzViYzSmjPWBGe+jbg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kkzvxfHKo8ZK7bwH/pWwCsfmNTNgjJSFz5pQIp/sns5nd83Y/kkqbfZWxdmgK7QId /ACwi2k7kq0a/gooH953KjSK/k+n32AY38dFLLEQ02OtmzyciqDuvu9Fne04L4hBCF ASmWJxXCL+n5MhX1fQJyb2VSPLfqWelj8GQ4GIwU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+8993c0fa96d57c399735@syzkaller.appspotmail.com, "Michael S. Tsirkin" , John Fastabend , Jason Wang , Cong Wang , "David S. Miller" Subject: [PATCH 4.9 29/71] ptr_ring: wrap back ->producer in __ptr_ring_swap_queue() Date: Mon, 7 Jan 2019 13:32:58 +0100 Message-Id: <20190107105334.421191654@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190107105330.280153213@linuxfoundation.org> References: <20190107105330.280153213@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cong Wang [ Upstream commit aff6db454599d62191aabc208930e891748e4322 ] __ptr_ring_swap_queue() tries to move pointers from the old ring to the new one, but it forgets to check if ->producer is beyond the new size at the end of the operation. This leads to an out-of-bound access in __ptr_ring_produce() as reported by syzbot. Reported-by: syzbot+8993c0fa96d57c399735@syzkaller.appspotmail.com Fixes: 5d49de532002 ("ptr_ring: resize support") Cc: "Michael S. Tsirkin" Cc: John Fastabend Cc: Jason Wang Signed-off-by: Cong Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/linux/ptr_ring.h | 2 ++ 1 file changed, 2 insertions(+) --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -384,6 +384,8 @@ static inline void **__ptr_ring_swap_que else if (destroy) destroy(ptr); + if (producer >= size) + producer = 0; r->size = size; r->producer = producer; r->consumer = 0;