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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 703F4C32750 for ; Fri, 2 Aug 2019 09:46:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4946A2087E for ; Fri, 2 Aug 2019 09:46:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739201; bh=+aGx93teK49sgP9s+2liXHxJDHCADvwjKFT2BB0hRfI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LjGKvSHk4Een0G0WYCAsTSD405jI0bRrruU9Pe/4WieKf1UroajFOiIddenRKeCX/ pX8bjTS4cjuApz1UYwxlEkfKdc4emBcCB8xKLpWKiHX2IJHa9227aa++dzHS9hLVqf Rup5ZUdfagL1rqaoKKmYzdB/vxHRqvkefoTSKZwQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404704AbfHBJqj (ORCPT ); Fri, 2 Aug 2019 05:46:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:51028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405581AbfHBJqh (ORCPT ); Fri, 2 Aug 2019 05:46:37 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 542A8206A2; Fri, 2 Aug 2019 09:46:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739195; bh=+aGx93teK49sgP9s+2liXHxJDHCADvwjKFT2BB0hRfI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZwVUzVswKyg1TPXZi/iEOIPYXJUzzmf9NXFqYCk2zAgAjEv7mYkkzA9H0UvPl7SDy BtamfYMp0p4gmfQwl1gpMdAzCQJBvSRZH3msnEiPyK6Z+uBNG2P1fBdvtaFq39jZT3 XRo/yiEiPecjOFEFSZl1X+igy6OYlnXn5ypDHPKI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marek Majkowski , Lorenzo Bianconi , David Ahern , "David S. Miller" Subject: [PATCH 4.9 136/223] net: neigh: fix multiple neigh timer scheduling Date: Fri, 2 Aug 2019 11:36:01 +0200 Message-Id: <20190802092247.655489587@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190802092238.692035242@linuxfoundation.org> References: <20190802092238.692035242@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Lorenzo Bianconi [ Upstream commit 071c37983d99da07797294ea78e9da1a6e287144 ] Neigh timer can be scheduled multiple times from userspace adding multiple neigh entries and forcing the neigh timer scheduling passing NTF_USE in the netlink requests. This will result in a refcount leak and in the following dump stack: [ 32.465295] NEIGH: BUG, double timer add, state is 8 [ 32.465308] CPU: 0 PID: 416 Comm: double_timer_ad Not tainted 5.2.0+ #65 [ 32.465311] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-2.fc30 04/01/2014 [ 32.465313] Call Trace: [ 32.465318] dump_stack+0x7c/0xc0 [ 32.465323] __neigh_event_send+0x20c/0x880 [ 32.465326] ? ___neigh_create+0x846/0xfb0 [ 32.465329] ? neigh_lookup+0x2a9/0x410 [ 32.465332] ? neightbl_fill_info.constprop.0+0x800/0x800 [ 32.465334] neigh_add+0x4f8/0x5e0 [ 32.465337] ? neigh_xmit+0x620/0x620 [ 32.465341] ? find_held_lock+0x85/0xa0 [ 32.465345] rtnetlink_rcv_msg+0x204/0x570 [ 32.465348] ? rtnl_dellink+0x450/0x450 [ 32.465351] ? mark_held_locks+0x90/0x90 [ 32.465354] ? match_held_lock+0x1b/0x230 [ 32.465357] netlink_rcv_skb+0xc4/0x1d0 [ 32.465360] ? rtnl_dellink+0x450/0x450 [ 32.465363] ? netlink_ack+0x420/0x420 [ 32.465366] ? netlink_deliver_tap+0x115/0x560 [ 32.465369] ? __alloc_skb+0xc9/0x2f0 [ 32.465372] netlink_unicast+0x270/0x330 [ 32.465375] ? netlink_attachskb+0x2f0/0x2f0 [ 32.465378] netlink_sendmsg+0x34f/0x5a0 [ 32.465381] ? netlink_unicast+0x330/0x330 [ 32.465385] ? move_addr_to_kernel.part.0+0x20/0x20 [ 32.465388] ? netlink_unicast+0x330/0x330 [ 32.465391] sock_sendmsg+0x91/0xa0 [ 32.465394] ___sys_sendmsg+0x407/0x480 [ 32.465397] ? copy_msghdr_from_user+0x200/0x200 [ 32.465401] ? _raw_spin_unlock_irqrestore+0x37/0x40 [ 32.465404] ? lockdep_hardirqs_on+0x17d/0x250 [ 32.465407] ? __wake_up_common_lock+0xcb/0x110 [ 32.465410] ? __wake_up_common+0x230/0x230 [ 32.465413] ? netlink_bind+0x3e1/0x490 [ 32.465416] ? netlink_setsockopt+0x540/0x540 [ 32.465420] ? __fget_light+0x9c/0xf0 [ 32.465423] ? sockfd_lookup_light+0x8c/0xb0 [ 32.465426] __sys_sendmsg+0xa5/0x110 [ 32.465429] ? __ia32_sys_shutdown+0x30/0x30 [ 32.465432] ? __fd_install+0xe1/0x2c0 [ 32.465435] ? lockdep_hardirqs_off+0xb5/0x100 [ 32.465438] ? mark_held_locks+0x24/0x90 [ 32.465441] ? do_syscall_64+0xf/0x270 [ 32.465444] do_syscall_64+0x63/0x270 [ 32.465448] entry_SYSCALL_64_after_hwframe+0x49/0xbe Fix the issue unscheduling neigh_timer if selected entry is in 'IN_TIMER' receiving a netlink request with NTF_USE flag set Reported-by: Marek Majkowski Fixes: 0c5c2d308906 ("neigh: Allow for user space users of the neighbour table") Signed-off-by: Lorenzo Bianconi Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/neighbour.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -982,6 +982,7 @@ int __neigh_event_send(struct neighbour atomic_set(&neigh->probes, NEIGH_VAR(neigh->parms, UCAST_PROBES)); + neigh_del_timer(neigh); neigh->nud_state = NUD_INCOMPLETE; neigh->updated = now; next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME), @@ -998,6 +999,7 @@ int __neigh_event_send(struct neighbour } } else if (neigh->nud_state & NUD_STALE) { neigh_dbg(2, "neigh %p is delayed\n", neigh); + neigh_del_timer(neigh); neigh->nud_state = NUD_DELAY; neigh->updated = jiffies; neigh_add_timer(neigh, jiffies +