From c2a94de38c74e86f49124ac14f093d6a5c377a90 Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Mon, 25 Jul 2022 18:13:59 +0300 Subject: [PATCH] wifi: ath9k: hif_usb: fix memory leak of urbs in ath9k_hif_usb_dealloc_tx_urbs() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Syzkaller reports a long-known leak of urbs in ath9k_hif_usb_dealloc_tx_urbs(). The cause of the leak is that usb_get_urb() is called but usb_free_urb() (or usb_put_urb()) is not called inside usb_kill_urb() as urb->dev or urb->ep fields have not been initialized and usb_kill_urb() returns immediately. The patch removes trying to kill urbs located in hif_dev->tx.tx_buf because hif_dev->tx.tx_buf is not supposed to contain urbs which are in pending state (the pending urbs are stored in hif_dev->tx.tx_pending). The tx.tx_lock is acquired so there should not be any changes in the list. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 03fb92a432ea ("ath9k: hif_usb: fix race condition between usb_get_urb() and usb_kill_anchored_urbs()") Signed-off-by: Fedor Pchelkin Signed-off-by: Alexey Khoroshilov Acked-by: Toke Høiland-Jørgensen Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20220725151359.283704-1-pchelkin@ispras.ru --- drivers/net/wireless/ath/ath9k/hif_usb.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index 4d9002a9..b6b5ce9 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -780,14 +780,10 @@ static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev) spin_lock_irqsave(&hif_dev->tx.tx_lock, flags); list_for_each_entry_safe(tx_buf, tx_buf_tmp, &hif_dev->tx.tx_buf, list) { - usb_get_urb(tx_buf->urb); - spin_unlock_irqrestore(&hif_dev->tx.tx_lock, flags); - usb_kill_urb(tx_buf->urb); list_del(&tx_buf->list); usb_free_urb(tx_buf->urb); kfree(tx_buf->buf); kfree(tx_buf); - spin_lock_irqsave(&hif_dev->tx.tx_lock, flags); } spin_unlock_irqrestore(&hif_dev->tx.tx_lock, flags); -- 2.7.4