From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Schiller Subject: Re: [PATCH 2/4] wan/hdlc_x25: fix skb handling Date: Fri, 05 Apr 2019 08:56:44 +0200 Message-ID: References: <20190403050118.12785-1-ms@dev.tdt.de> <20190403050118.12785-2-ms@dev.tdt.de> <20190404.173240.1338878948110207179.davem@davemloft.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190404.173240.1338878948110207179.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: David Miller Cc: andrew.hendry@gmail.com, khc@pm.waw.pl, isdn@linux-pingi.de, edumazet@google.com, linux-x25@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org On 2019-04-05 02:32, David Miller wrote: > From: Martin Schiller > Date: Wed, 3 Apr 2019 07:01:16 +0200 > >> /* X.25 to LAPB */ >> switch (skb->data[0]) { >> case X25_IFACE_DATA: /* Data to be transmitted */ >> - skb_pull(skb, 1); >> - if ((result = lapb_data_request(dev, skb)) != LAPB_OK) >> - dev_kfree_skb(skb); >> - return NETDEV_TX_OK; >> + skbn = skb_copy(skb, GFP_ATOMIC); >> + skb_pull(skbn, 1); >> + skb_reset_network_header(skbn); >> + if ((result = lapb_data_request(dev, skbn)) != LAPB_OK) >> + dev_kfree_skb(skbn); > > This leaks 'skb'. What exactly do you mean? 'skb' will get freed at the end of x25_xmit() function: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wan/hdlc_x25.c#n129 > > No way I'm applying this stuff.