From patchwork Mon Dec 21 21:07:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Davide Caratti X-Patchwork-Id: 11985303 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 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 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 A4638C433DB for ; Mon, 21 Dec 2020 21:09:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61EB2207C7 for ; Mon, 21 Dec 2020 21:09:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726033AbgLUVJN (ORCPT ); Mon, 21 Dec 2020 16:09:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38291 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725782AbgLUVJN (ORCPT ); Mon, 21 Dec 2020 16:09:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608584866; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Tx18mp9v4B2r39J0YYvmVCl7t6UEuYsHm4CFtxAruBk=; b=hL1E/fFNc2d+n33/Bsq4lSn6PGQ66l62HqvFbfGJOQujX439/FrH20rb+C8/6QIeEY59Jf tCvwDXEWgPTCRrVHXHEXVnbrkYgoTZUg+GBO8Ikaq3FKRFQTE3IF0naIa/VfHIjBsCQqHM w5Ybw3lm0OCayV8WNHB81z5mJswDGwQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-85-jsxpdfRFOfq-doB6P9iOgQ-1; Mon, 21 Dec 2020 16:07:42 -0500 X-MC-Unique: jsxpdfRFOfq-doB6P9iOgQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3141B8015C6; Mon, 21 Dec 2020 21:07:41 +0000 (UTC) Received: from new-host-6.station (unknown [10.40.193.70]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5DC32620D7; Mon, 21 Dec 2020 21:07:39 +0000 (UTC) From: Davide Caratti To: Mat Martineau , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: Matthieu Baerts , mptcp@lists.01.org, netdev@vger.kernel.org Subject: [PATCH net] net: mptcp: cap forward allocation to 1M Date: Mon, 21 Dec 2020 22:07:25 +0100 Message-Id: <3334d00d8b2faecafdfab9aa593efcbf61442756.1608584474.git.dcaratti@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org the following syzkaller reproducer: r0 = socket$inet_mptcp(0x2, 0x1, 0x106) bind$inet(r0, &(0x7f0000000080)={0x2, 0x4e24, @multicast2}, 0x10) connect$inet(r0, &(0x7f0000000480)={0x2, 0x4e24, @local}, 0x10) sendto$inet(r0, &(0x7f0000000100)="f6", 0xffffffe7, 0xc000, 0x0, 0x0) systematically triggers the following warning: WARNING: CPU: 2 PID: 8618 at net/core/stream.c:208 sk_stream_kill_queues+0x3fa/0x580 Modules linked in: CPU: 2 PID: 8618 Comm: syz-executor Not tainted 5.10.0+ #334 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/04 RIP: 0010:sk_stream_kill_queues+0x3fa/0x580 Code: df 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 40 8b ab 20 02 00 00 e9 64 ff ff ff e8 df f0 81 2 RSP: 0018:ffffc9000290fcb0 EFLAGS: 00010293 RAX: ffff888011cb8000 RBX: 0000000000000000 RCX: ffffffff86eecf0e RDX: 0000000000000000 RSI: ffffffff86eecf6a RDI: 0000000000000005 RBP: 0000000000000e28 R08: ffff888011cb8000 R09: fffffbfff1f48139 R10: ffffffff8fa409c7 R11: fffffbfff1f48138 R12: ffff8880215e6220 R13: ffffffff8fa409c0 R14: ffffc9000290fd30 R15: 1ffff92000521fa2 FS: 00007f41c78f4800(0000) GS:ffff88802d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95c803d088 CR3: 0000000025ed2000 CR4: 00000000000006f0 Call Trace: __mptcp_destroy_sock+0x4f5/0x8e0 mptcp_close+0x5e2/0x7f0 inet_release+0x12b/0x270 __sock_release+0xc8/0x270 sock_close+0x18/0x20 __fput+0x272/0x8e0 task_work_run+0xe0/0x1a0 exit_to_user_mode_prepare+0x1df/0x200 syscall_exit_to_user_mode+0x19/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 userspace programs provide arbitrarily high values of 'len' in sendmsg(): this is causing integer overflow of 'amount'. Cap forward allocation to 1 megabyte: higher values are not really useful. Suggested-by: Paolo Abeni Fixes: e93da92896bc ("mptcp: implement wmem reservation") Signed-off-by: Davide Caratti --- net/mptcp/protocol.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 09b19aa2f205..6628d8d74203 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -877,6 +877,9 @@ static void __mptcp_wmem_reserve(struct sock *sk, int size) struct mptcp_sock *msk = mptcp_sk(sk); WARN_ON_ONCE(msk->wmem_reserved); + if (WARN_ON_ONCE(amount < 0)) + amount = 0; + if (amount <= sk->sk_forward_alloc) goto reserve; @@ -1587,7 +1590,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) return -EOPNOTSUPP; - mptcp_lock_sock(sk, __mptcp_wmem_reserve(sk, len)); + mptcp_lock_sock(sk, __mptcp_wmem_reserve(sk, min_t(size_t, 1 << 20, len))); timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);