From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: BUG in netxen_release_tx_buffers when TSO enabled on kernels >= 3.3 and <= 3.6 Date: Tue, 22 Jan 2013 08:33:05 -0800 Message-ID: <1358872385.3464.3940.camel@edumazet-glaptop> References: <1659861.dHpGAGoXHj@cpaasch-mac> <1358862966.3464.3797.camel@edumazet-glaptop> <2166577.r0iRQtU7qE@cpaasch-mac> <3172160.NCYvLW6RVJ@cpaasch-mac> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Ian Campbell , Sony Chacko , Rajesh Borundia , David Miller , netdev@vger.kernel.org To: christoph.paasch@uclouvain.be Return-path: Received: from mail-da0-f51.google.com ([209.85.210.51]:37614 "EHLO mail-da0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754468Ab3AVQdK (ORCPT ); Tue, 22 Jan 2013 11:33:10 -0500 Received: by mail-da0-f51.google.com with SMTP id i30so3292933dad.38 for ; Tue, 22 Jan 2013 08:33:10 -0800 (PST) In-Reply-To: <3172160.NCYvLW6RVJ@cpaasch-mac> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet On Tue, 2013-01-22 at 16:43 +0100, Christoph Paasch wrote: > In netxen_map_tx_skb() I think we also have to set nf->dma to 0ULL (like the > diff below). > > Otherwise, netxen_release_tx_buffer() may try to unmap something that has > already been unmapped. > > I'm not sure - I don't feel very comfortable in driver-code... It seems fine to me, here is the official combined patch, feel free to add your 'Signed-off-by' Thanks ! [PATCH] netxen: fix off by one bug in netxen_release_tx_buffer() Christoph Paasch found netxen could trigger a BUG in its dismantle phase, in netxen_release_tx_buffer(), using full size TSO packets. cmd_buf->frag_count includes the skb->data part, so the loop must start at index 1 instead of 0, or else we can make an out of bound access to cmd_buff->frag_array[MAX_SKB_FRAGS + 2] Christoph provided the fixes in netxen_map_tx_skb() function. In case of a dma mapping error, its better to clear the dma fields so that we don't try to unmap them again in netxen_release_tx_buffer() Reported-by: Christoph Paasch Signed-off-by: Eric Dumazet Tested-by: Christoph Paasch Cc: Sony Chacko Cc: Rajesh Borundia --- drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c | 2 +- drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c b/drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c index bc165f4..695667d 100644 --- a/drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c +++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c @@ -144,7 +144,7 @@ void netxen_release_tx_buffers(struct netxen_adapter *adapter) buffrag->length, PCI_DMA_TODEVICE); buffrag->dma = 0ULL; } - for (j = 0; j < cmd_buf->frag_count; j++) { + for (j = 1; j < cmd_buf->frag_count; j++) { buffrag++; if (buffrag->dma) { pci_unmap_page(adapter->pdev, buffrag->dma, diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c index 6098fd4a..69e321a 100644 --- a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c +++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c @@ -1963,10 +1963,12 @@ unwind: while (--i >= 0) { nf = &pbuf->frag_array[i+1]; pci_unmap_page(pdev, nf->dma, nf->length, PCI_DMA_TODEVICE); + nf->dma = 0ULL; } nf = &pbuf->frag_array[0]; pci_unmap_single(pdev, nf->dma, skb_headlen(skb), PCI_DMA_TODEVICE); + nf->dma = 0ULL; out_err: return -ENOMEM;