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=-16.3 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, URIBL_BLOCKED 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 D8739C433DB for ; Wed, 10 Feb 2021 21:29:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9724B64E66 for ; Wed, 10 Feb 2021 21:29:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232715AbhBJV3e (ORCPT ); Wed, 10 Feb 2021 16:29:34 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:58150 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233680AbhBJV16 (ORCPT ); Wed, 10 Feb 2021 16:27:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612992387; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Em5vzDj4sgvjrXfPj5+8wn5Xjp/cMSRuzZO79Tyy4JI=; b=CRsU9VqDXGp4lbnHB4V2hv5kbXmVuPwKnpl1aLH5Tl+NDoDcwtBS4tos1EmWz7qAJCaOYy t75h5SQtPjDdBuScpzPuyqeeTwid55xOGf9AdB9vq1L4JP8Cff6zjpPXwIjYUyswuNLHLD qEdCYsNzLXfcuuFtfF1pGrfzbs4GloE= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-539-7SIbNM9GM0aFsRciPueviw-1; Wed, 10 Feb 2021 16:26:25 -0500 X-MC-Unique: 7SIbNM9GM0aFsRciPueviw-1 Received: by mail-wm1-f72.google.com with SMTP id z67so2017941wme.3 for ; Wed, 10 Feb 2021 13:26:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Em5vzDj4sgvjrXfPj5+8wn5Xjp/cMSRuzZO79Tyy4JI=; b=MmghmsNLpAKjQLg5nWuRP1+s7gNuX30194W3hBHaKc8uwhmFRwu0oUfd0eadR4HPlK TC75CRJEj/KLNjlvMEQCK0BPh1LQcNeBXzNQCEWR30Jj3xH8oWAdT4qF9n/V91xuzPXd xUyk+kE1y2eUU8eN9ZVsUNIHvkcIIXg0dKy5vvaaEcT+o2zlpR5vm4xA5Qtfz8BS8rlH u/IWhenWN2tGVcinH1uxPgRjFfYirt/NcwR70kufBEQ6dAAnzYemlvlx5Wappy9Ldae7 8SoAIYq5mAsP5Zttt4vpRESnqhptC/ie52xh0ZYg064Jye4HPoj7pCb6KqF2egIaosP9 CC6Q== X-Gm-Message-State: AOAM530tk82dSzBExsjS+vh/y9YEABrwBNYv3q8FbolGEV/j/cuxJ1QA yOAmi6pC8bQIlELFrj7837GSgodTyBqab7l5C9yrA06lKX8yVdR7WVLIhVkUuAp6gV1QwHaCuZ8 Mkt41xLzr6hmKlFKMCEmjhpKF X-Received: by 2002:a05:600c:2241:: with SMTP id a1mr1004104wmm.121.1612992383618; Wed, 10 Feb 2021 13:26:23 -0800 (PST) X-Google-Smtp-Source: ABdhPJx9dfJV8DIG8lS+bsoQkEgMSc78A244yldCq2uZ/iBHF51+u8MmXnI/m+D8ozEEqtRKJ5SdaA== X-Received: by 2002:a05:600c:2241:: with SMTP id a1mr1004091wmm.121.1612992383443; Wed, 10 Feb 2021 13:26:23 -0800 (PST) Received: from redhat.com (bzq-79-180-2-31.red.bezeqint.net. [79.180.2.31]) by smtp.gmail.com with ESMTPSA id t126sm4720967wmf.3.2021.02.10.13.26.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Feb 2021 13:26:21 -0800 (PST) Date: Wed, 10 Feb 2021 16:26:17 -0500 From: "Michael S. Tsirkin" To: Eric Dumazet Cc: linux-kernel , Eric Dumazet , syzbot , Parav Pandit , Eli Cohen , Jason Wang Subject: Re: [PATCH linux-next] vpda: correctly size vdpa_nl_policy Message-ID: <20210210162559-mutt-send-email-mst@kernel.org> References: <20210210134911.4119555-1-eric.dumazet@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210210134911.4119555-1-eric.dumazet@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 10, 2021 at 05:49:11AM -0800, Eric Dumazet wrote: > From: Eric Dumazet > > We need to ensure last entry of vdpa_nl_policy[] > is zero, otherwise out-of-bounds access is hurting us. > > BUG: KASAN: global-out-of-bounds in netlink_policy_dump_add_policy+0x3b6/0x440 net/netlink/policy.c:160 > Read of size 1 at addr ffffffff89cc61d0 by task syz-executor181/8413 > > CPU: 0 PID: 8413 Comm: syz-executor181 Not tainted 5.11.0-rc6-next-20210205-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0x107/0x163 lib/dump_stack.c:120 > print_address_description.constprop.0.cold+0x5/0x2f8 mm/kasan/report.c:232 > __kasan_report mm/kasan/report.c:399 [inline] > kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 > netlink_policy_dump_add_policy+0x3b6/0x440 net/netlink/policy.c:160 > ctrl_dumppolicy_start+0x3e1/0x760 net/netlink/genetlink.c:1181 > genl_start+0x3cc/0x670 net/netlink/genetlink.c:604 > __netlink_dump_start+0x584/0x900 net/netlink/af_netlink.c:2363 > genl_family_rcv_msg_dumpit+0x2af/0x310 net/netlink/genetlink.c:686 > genl_family_rcv_msg net/netlink/genetlink.c:780 [inline] > genl_rcv_msg+0x434/0x580 net/netlink/genetlink.c:800 > netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 > genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 > netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] > netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 > netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919 > sock_sendmsg_nosec net/socket.c:654 [inline] > sock_sendmsg+0xcf/0x120 net/socket.c:674 > ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350 > ___sys_sendmsg+0xf3/0x170 net/socket.c:2404 > __sys_sendmsg+0xe5/0x1b0 net/socket.c:2437 > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x43ef29 > Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007ffc75c06108 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ef29 > RDX: 0000000000000000 RSI: 00000000200029c0 RDI: 0000000000000003 > RBP: 0000000000402f10 R08: 00000000004ac018 R09: 0000000000400488 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402fa0 > R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488 > > The buggy address belongs to the variable: > vdpa_nl_policy+0x90/0x3a00 > > Memory state around the buggy address: > ffffffff89cc6080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffffffff89cc6100: 00 00 00 00 f9 f9 f9 f9 00 00 00 00 00 00 00 00 > >ffffffff89cc6180: 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 > ^ > ffffffff89cc6200: 05 f9 f9 f9 f9 f9 f9 f9 00 00 07 f9 f9 f9 f9 f9 > ffffffff89cc6280: 00 00 00 01 f9 f9 f9 f9 00 07 f9 f9 f9 f9 f9 f9 > > Fixes: be7f5be9e84a ("vdpa: Define vdpa mgmt device, ops and a netlink interface") > Signed-off-by: Eric Dumazet > Reported-by: syzbot > Cc: Parav Pandit > Cc: Eli Cohen > Cc: Jason Wang > Cc: Michael S. Tsirkin Oh good point, thanks! Acked-by: Michael S. Tsirkin > --- > drivers/vdpa/vdpa.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index 9700a0adcca089fe9abb0b211fada314fa4a04ef..3d997b3893452f4da6a6800e128c57a9a024c0ad 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -603,7 +603,7 @@ static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callba > return msg->len; > } > > -static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX] = { > +static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = { > [VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING }, > [VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING }, > [VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING }, > -- > 2.30.0.478.g8a0d178c01-goog