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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 C8005C433DB for ; Mon, 15 Feb 2021 16:04:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FAAC64DEB for ; Mon, 15 Feb 2021 16:04:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232614AbhBOQC2 (ORCPT ); Mon, 15 Feb 2021 11:02:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:46856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230494AbhBOPdE (ORCPT ); Mon, 15 Feb 2021 10:33:04 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 66DB764EB3; Mon, 15 Feb 2021 15:30:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613403022; bh=QDBg45RFT+SOm/lag6l4rj0iybT9eBugjWUvyOd+7iY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DxVzB8Bz/zsHEqNuOK3si8c3LmxY/dgOcYNdH+z3K5g7qBT8sHkZdS01LpB+lbH3n VMNTLqqRE53iPLXDoKXjuxJgJCCmqGKhC44na1OGfZlYSpCnzHY4JHG5wftG1z3oDj PaBqu7eZffPvvjv724qwkyJ+h6ZrLi1q0RuO/Kuc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+c2a7e5c5211605a90865@syzkaller.appspotmail.com, Sabyrzhan Tasbolatov , Jakub Kicinski Subject: [PATCH 5.4 59/60] net/qrtr: restrict user-controlled length in qrtr_tun_write_iter() Date: Mon, 15 Feb 2021 16:27:47 +0100 Message-Id: <20210215152717.273523982@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210215152715.401453874@linuxfoundation.org> References: <20210215152715.401453874@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: Sabyrzhan Tasbolatov commit 2a80c15812372e554474b1dba0b1d8e467af295d upstream. syzbot found WARNING in qrtr_tun_write_iter [1] when write_iter length exceeds KMALLOC_MAX_SIZE causing order >= MAX_ORDER condition. Additionally, there is no check for 0 length write. [1] WARNING: mm/page_alloc.c:5011 [..] Call Trace: alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2267 alloc_pages include/linux/gfp.h:547 [inline] kmalloc_order+0x2e/0xb0 mm/slab_common.c:837 kmalloc_order_trace+0x14/0x120 mm/slab_common.c:853 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:682 [inline] qrtr_tun_write_iter+0x8a/0x180 net/qrtr/tun.c:83 call_write_iter include/linux/fs.h:1901 [inline] Reported-by: syzbot+c2a7e5c5211605a90865@syzkaller.appspotmail.com Signed-off-by: Sabyrzhan Tasbolatov Link: https://lore.kernel.org/r/20210202092059.1361381-1-snovitoll@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/qrtr/tun.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/qrtr/tun.c +++ b/net/qrtr/tun.c @@ -80,6 +80,12 @@ static ssize_t qrtr_tun_write_iter(struc ssize_t ret; void *kbuf; + if (!len) + return -EINVAL; + + if (len > KMALLOC_MAX_SIZE) + return -ENOMEM; + kbuf = kzalloc(len, GFP_KERNEL); if (!kbuf) return -ENOMEM;