From 9494849e53e74048ee14d512feade01db402eef7 Mon Sep 17 00:00:00 2001 From: Alexey Khoroshilov <khoroshilov@ispras.ru> Date: Tue, 2 Jul 2013 00:43:42 +0400 Subject: [PATCH] ath9k_htc: fix data race between request_firmware_nowait() callback and suspend() 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 <khoroshilov@ispras.ru> Signed-off-by: John W. Linville <linville@tuxdriver.com> --- 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 9e582e14da746..2469db5a5bb1d 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -1082,7 +1082,7 @@ 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); @@ -1131,7 +1131,7 @@ 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; @@ -1316,7 +1316,10 @@ 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; } -- GitLab