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=unavailable 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 0488FC43387 for ; Mon, 7 Jan 2019 12:37:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C91022089F for ; Mon, 7 Jan 2019 12:37:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546864627; bh=L5RodkvpLjH/zO8+iHr8lS2OHyECnoxBxqNwpiPPODA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SCp42AUbNAQ/Z6t53Fa966BRTECSt6jmQpA7XN1BSJPUAUHH14KuGDoN4He3xTwKc W4qLBIrwOC0zvW33Er9laRLILhd0P3hzlSMXo12/zimLGFLuIZZlnGKoBlIAQirfJI IoLl9DKSQwvsvslffoeV84+xuh1CA9GM6ziZjiIY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727458AbfAGMhC (ORCPT ); Mon, 7 Jan 2019 07:37:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:51840 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726718AbfAGMhB (ORCPT ); Mon, 7 Jan 2019 07:37:01 -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 4BDFC21736; Mon, 7 Jan 2019 12:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546864621; bh=L5RodkvpLjH/zO8+iHr8lS2OHyECnoxBxqNwpiPPODA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a86kehcKzHiwRjv5IKj+lyMiFxTAkXsUyc8dd3zVaSMjyWtO9rPwEJMhFyOCsbirA 85pS7dZjHTrMqr1ulldnGMPiA0HFzieJqdANOsdomtLRgWdy99fXJ8pTQU01UwIYUE JIDK/DnZ4JvGlzlbKhaQXXOjyyI/FVS/scmDvgbU= 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 4.20 017/145] ptr_ring: wrap back ->producer in __ptr_ring_swap_queue() Date: Mon, 7 Jan 2019 13:30:54 +0100 Message-Id: <20190107104439.576609858@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190107104437.308206189@linuxfoundation.org> References: <20190107104437.308206189@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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-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 @@ -573,6 +573,8 @@ static inline void **__ptr_ring_swap_que else if (destroy) destroy(ptr); + if (producer >= size) + producer = 0; __ptr_ring_set_size(r, size); r->producer = producer; r->consumer_head = 0;