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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9AB7C433EF for ; Fri, 6 May 2022 03:28:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1388550AbiEFDcH (ORCPT ); Thu, 5 May 2022 23:32:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1388539AbiEFDcC (ORCPT ); Thu, 5 May 2022 23:32:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58B15644C0; Thu, 5 May 2022 20:28:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 219B5B832C4; Fri, 6 May 2022 03:28:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 685DEC385AC; Fri, 6 May 2022 03:28:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651807698; bh=/Busav/MercVn3U7qos3BeCdpeFW+y8S+aaQ9UEgLOg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=jsBG26qh+s213Ai58L/c76nzSly7WUrMn1CW1KN9i9Ky51OURpsDA8Sue2D1CJ9Sq D8CjECh08aUOh24sOOD33Rszb5HqzS3oCrMHt7J9QZ5KK7ThbTIN8fWjSxQGvAxN6Q wdSWi/aFNzQ4Fsh/B+YFmhpQTvm3gFaA7Eu/Kznm3H/n3c1g3DKxwrUj8NDa4bbkUr dTaDkNqV1drIVgG1E8DYViBhnnKaMxvcP6cr9gNLtlfs6p8gtWeqONXKRInUx3IuES matYNYW+DmzRSrK9oWJeilQ6ahPS2ea5Mt7yGypTxX+HYFgfWH2LN7Lpta8o7j2xya hf/isN0EBWRXQ== Message-ID: <366d529e-6149-423a-e012-dbfd9c41baac@kernel.org> Date: Thu, 5 May 2022 20:28:16 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [net PATCH] ipv4: drop dst in multicast routing path Content-Language: en-US To: Chris Packham , davem@davemloft.net, yoshfuji@linux-ipv6.org, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, tgraf@suug.ch, lokesh.dhoundiyal@alliedtelesis.co.nz Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20220505020017.3111846-1-chris.packham@alliedtelesis.co.nz> From: David Ahern In-Reply-To: <20220505020017.3111846-1-chris.packham@alliedtelesis.co.nz> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 5/4/22 7:00 PM, Chris Packham wrote: > From: Lokesh Dhoundiyal > > kmemleak reports the following when routing multicast traffic over an > ipsec tunnel. > > Kmemleak output: > unreferenced object 0x8000000044bebb00 (size 256): > comm "softirq", pid 0, jiffies 4294985356 (age 126.810s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 80 00 00 00 05 13 74 80 ..............t. > 80 00 00 00 04 9b bf f9 00 00 00 00 00 00 00 00 ................ > backtrace: > [<00000000f83947e0>] __kmalloc+0x1e8/0x300 > [<00000000b7ed8dca>] metadata_dst_alloc+0x24/0x58 > [<0000000081d32c20>] __ipgre_rcv+0x100/0x2b8 > [<00000000824f6cf1>] gre_rcv+0x178/0x540 > [<00000000ccd4e162>] gre_rcv+0x7c/0xd8 > [<00000000c024b148>] ip_protocol_deliver_rcu+0x124/0x350 > [<000000006a483377>] ip_local_deliver_finish+0x54/0x68 > [<00000000d9271b3a>] ip_local_deliver+0x128/0x168 > [<00000000bd4968ae>] xfrm_trans_reinject+0xb8/0xf8 > [<0000000071672a19>] tasklet_action_common.isra.16+0xc4/0x1b0 > [<0000000062e9c336>] __do_softirq+0x1fc/0x3e0 > [<00000000013d7914>] irq_exit+0xc4/0xe0 > [<00000000a4d73e90>] plat_irq_dispatch+0x7c/0x108 > [<000000000751eb8e>] handle_int+0x16c/0x178 > [<000000001668023b>] _raw_spin_unlock_irqrestore+0x1c/0x28 > > The metadata dst is leaked when ip_route_input_mc() updates the dst for > the skb. Commit f38a9eb1f77b ("dst: Metadata destinations") correctly > handled dropping the dst in ip_route_input_slow() but missed the > multicast case which is handled by ip_route_input_mc(). Drop the dst in > ip_route_input_mc() avoiding the leak. > > Fixes: f38a9eb1f77b ("dst: Metadata destinations") > Signed-off-by: Lokesh Dhoundiyal > Signed-off-by: Chris Packham > --- > > Notes: > We started seeing this leak in our scenario after commit c0d59da79534 > ("ip_gre: Make none-tun-dst gre tunnel store tunnel info as metadat_dst > in recv") but there may be other paths that hit the leak so I've set the > fixes tag as f38a9eb1f77b ("dst: Metadata destinations"). > > net/ipv4/route.c | 1 + > 1 file changed, 1 insertion(+) > Reviewed-by: David Ahern