Return-path: Received: from sd-mail-sa-01.sanoma.fi ([158.127.18.161]:59894 "EHLO sd-mail-sa-01.sanoma.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750838Ab2LTOYp (ORCPT ); Thu, 20 Dec 2012 09:24:45 -0500 Subject: [PATCH] rtlwifi: fix incorrect use of usb_alloc_coherent with usb_control_msg To: linux-wireless@vger.kernel.org From: Jussi Kivilinna Cc: Chaoming Li , "John W. Linville" , stable@vger.kernel.org, Larry Finger Date: Thu, 20 Dec 2012 16:24:43 +0200 Message-ID: <20121220142443.16895.45834.stgit@localhost6.localdomain6> (sfid-20121220_152450_235340_472C8CC3) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: Incorrect use of usb_alloc_coherent memory as input buffer to usb_control_msg can cause problems in arch DMA code, for example kernel BUG at 'arch/arm/include/asm/dma-mapping.h:321' on ARM (linux-3.4). Change _usb_writeN_sync use kmalloc'd buffer instead. Cc: stable@vger.kernel.org Signed-off-by: Jussi Kivilinna --- drivers/net/wireless/rtlwifi/usb.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c index 29f0969..a3312b7 100644 --- a/drivers/net/wireless/rtlwifi/usb.c +++ b/drivers/net/wireless/rtlwifi/usb.c @@ -210,17 +210,16 @@ static void _usb_writeN_sync(struct rtl_priv *rtlpriv, u32 addr, void *data, u16 index = REALTEK_USB_VENQT_CMD_IDX; int pipe = usb_sndctrlpipe(udev, 0); /* write_out */ u8 *buffer; - dma_addr_t dma_addr; - wvalue = (u16)(addr&0x0000ffff); - buffer = usb_alloc_coherent(udev, (size_t)len, GFP_ATOMIC, &dma_addr); + wvalue = (u16)(addr & 0x0000ffff); + buffer = kmalloc(len, GFP_ATOMIC); if (!buffer) return; memcpy(buffer, data, len); usb_control_msg(udev, pipe, request, reqtype, wvalue, index, buffer, len, 50); - usb_free_coherent(udev, (size_t)len, buffer, dma_addr); + kfree(buffer); } static void _rtl_usb_io_handler_init(struct device *dev,