Return-path: Received: from mail.ispras.ru ([83.149.199.45]:59373 "EHLO mail.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754818Ab3GAUoQ (ORCPT ); Mon, 1 Jul 2013 16:44:16 -0400 From: Alexey Khoroshilov To: "Luis R. Rodriguez" , Jouni Malinen , Vasanthakumar Thiagarajan , Senthil Balasubramanian Cc: Alexey Khoroshilov , "John W. Linville" , linux-wireless@vger.kernel.org, ath9k-devel@lists.ath9k.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH] ath9k_htc: fix data race between request_firmware_nowait() callback and suspend() Date: Tue, 2 Jul 2013 00:43:42 +0400 Message-Id: <1372711422-4604-1-git-send-email-khoroshilov@ispras.ru> (sfid-20130701_224432_086877_B5C59064) Sender: linux-wireless-owner@vger.kernel.org List-ID: ath9k_hif_usb_probe() requests firmware asynchronically and there is some initialization postponed till firmware is ready. In particular, ath9k_hif_usb_firmware_cb() callback initializes hif_dev->tx.tx_buf and hif_dev->tx.tx_pending lists. At the same time, ath9k_hif_usb_suspend() iterates that lists through ath9k_hif_usb_dealloc_urbs(). If suspend happens before request_firmware_nowait() callback is called, it can lead to oops. Similar issue could be in ath9k_hif_usb_disconnect(), but it is prevented using hif_dev->fw_done completion and HIF_USB_READY flag. The patch extends this approach to suspend() as well. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov --- drivers/net/wireless/ath/ath9k/hif_usb.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index f5dda84..fcd9aa5 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -1076,7 +1076,7 @@ static void ath9k_hif_usb_firmware_fail(struct hif_device_usb *hif_dev) struct device *dev = &hif_dev->udev->dev; struct device *parent = dev->parent; - complete(&hif_dev->fw_done); + complete_all(&hif_dev->fw_done); if (parent) device_lock(parent); @@ -1125,7 +1125,7 @@ static void ath9k_hif_usb_firmware_cb(const struct firmware *fw, void *context) release_firmware(fw); hif_dev->flags |= HIF_USB_READY; - complete(&hif_dev->fw_done); + complete_all(&hif_dev->fw_done); return; @@ -1310,7 +1310,10 @@ static int ath9k_hif_usb_suspend(struct usb_interface *interface, if (!(hif_dev->flags & HIF_USB_START)) ath9k_htc_suspend(hif_dev->htc_handle); - ath9k_hif_usb_dealloc_urbs(hif_dev); + wait_for_completion(&hif_dev->fw_done); + + if (hif_dev->flags & HIF_USB_READY) + ath9k_hif_usb_dealloc_urbs(hif_dev); return 0; } -- 1.8.1.2