From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753500AbdJFI57 (ORCPT ); Fri, 6 Oct 2017 04:57:59 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50228 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753450AbdJFI54 (ORCPT ); Fri, 6 Oct 2017 04:57:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anthony H Thai , Harsha Thyagaraja , Guilherme G Piccoli , Aaron Brown , Jeff Kirsher , Sasha Levin Subject: [PATCH 4.4 08/50] igb: re-assign hw address pointer on reset after PCI error Date: Fri, 6 Oct 2017 10:52:56 +0200 Message-Id: <20171006083706.471745544@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171006083705.157012217@linuxfoundation.org> References: <20171006083705.157012217@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guilherme G Piccoli [ Upstream commit 69b97cf6dbce7403845a28bbc75d57f5be7b12ac ] Whenever the igb driver detects the result of a read operation returns a value composed only by F's (like 0xFFFFFFFF), it will detach the net_device, clear the hw_addr pointer and warn to the user that adapter's link is lost - those steps happen on igb_rd32(). In case a PCI error happens on Power architecture, there's a recovery mechanism called EEH, that will reset the PCI slot and call driver's handlers to reset the adapter and network functionality as well. We observed that once hw_addr is NULL after the error is detected on igb_rd32(), it's never assigned back, so in the process of resetting the network functionality we got a NULL pointer dereference in both igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid such bug, this patch re-assigns the hw_addr value in the slot_reset handler. Reported-by: Anthony H Thai Reported-by: Harsha Thyagaraja Signed-off-by: Guilherme G Piccoli Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/intel/igb/igb_main.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -7658,6 +7658,11 @@ static pci_ers_result_t igb_io_slot_rese pci_enable_wake(pdev, PCI_D3hot, 0); pci_enable_wake(pdev, PCI_D3cold, 0); + /* In case of PCI error, adapter lose its HW address + * so we should re-assign it here. + */ + hw->hw_addr = adapter->io_addr; + igb_reset(adapter); wr32(E1000_WUS, ~0); result = PCI_ERS_RESULT_RECOVERED;