From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: [PATCH net-next 09/10] r8169: avoid potentially misaligned access when getting mac address Date: Wed, 2 May 2018 21:39:59 +0200 Message-ID: References: <2c7cae9e-d989-8529-7209-5a271242ce39@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "netdev@vger.kernel.org" To: David Miller , Realtek linux nic maintainers Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:37508 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751802AbeEBTkT (ORCPT ); Wed, 2 May 2018 15:40:19 -0400 Received: by mail-wm0-f66.google.com with SMTP id l1so26468178wmb.2 for ; Wed, 02 May 2018 12:40:19 -0700 (PDT) In-Reply-To: <2c7cae9e-d989-8529-7209-5a271242ce39@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Interpreting a member of an u16 array as u32 may result in a misaligned access. Also it's not really intuitive to define a mac address variable as array of three u16 words. Therefore use an array of six bytes that is properly aligned for 32 bit access. Signed-off-by: Heiner Kallweit --- drivers/net/ethernet/realtek/r8169.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index d72b3fdf..6fce3cc8 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -7767,14 +7767,14 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) /* Get MAC address */ switch (tp->mac_version) { - u16 mac_addr[3]; + u8 mac_addr[ETH_ALEN] __aligned(4); case RTL_GIGA_MAC_VER_35 ... RTL_GIGA_MAC_VER_38: case RTL_GIGA_MAC_VER_40 ... RTL_GIGA_MAC_VER_51: *(u32 *)&mac_addr[0] = rtl_eri_read(tp, 0xe0, ERIAR_EXGMAC); - *(u16 *)&mac_addr[2] = rtl_eri_read(tp, 0xe4, ERIAR_EXGMAC); + *(u16 *)&mac_addr[4] = rtl_eri_read(tp, 0xe4, ERIAR_EXGMAC); - if (is_valid_ether_addr((u8 *)mac_addr)) - rtl_rar_set(tp, (u8 *)mac_addr); + if (is_valid_ether_addr(mac_addr)) + rtl_rar_set(tp, mac_addr); break; default: break; -- 2.17.0