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ath9k: hif_usb: fix race condition between usb_get_urb() and usb_kill_anchored_urbs()

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Calls to usb_kill_anchored_urbs() after usb_kill_urb() on multiprocessor
systems create a race condition in which usb_kill_anchored_urbs() deallocates
the URB before the completer callback is called in usb_kill_urb(), resulting
in a use-after-free.
To fix this, add proper lock protection to usb_kill_urb() calls that can
possibly run concurrently with usb_kill_anchored_urbs().

Reported-by: syzbot+89bd486af9427a9fc605@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=cabffad18eb74197f84871802fd2c5117b61febf
Signed-off-by: Brooke Basile <brookebasile@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200911071427.32354-1-brookebasile@gmail.com
This commit is contained in:
Brooke Basile 2020-09-11 03:14:27 -04:00 committed by Kalle Valo
parent 5a6bd84f81
commit 03fb92a432
1 changed files with 19 additions and 0 deletions
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19
drivers/net/wireless/ath/ath9k/hif_usb.c
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@ -449,10 +449,19 @@ static void hif_usb_stop(void *hif_handle)
spin_unlock_irqrestore(&hif_dev->tx.tx_lock, flags);
/* The pending URBs have to be canceled. */
spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);
list_for_each_entry_safe(tx_buf, tx_buf_tmp,
&hif_dev->tx.tx_pending, 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);
usb_kill_anchored_urbs(&hif_dev->mgmt_submitted);
}
@ -762,27 +771,37 @@ static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev)
struct tx_buf *tx_buf = NULL, *tx_buf_tmp = NULL;
unsigned long flags;
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);
spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);
hif_dev->tx.flags |= HIF_USB_TX_FLUSH;
spin_unlock_irqrestore(&hif_dev->tx.tx_lock, flags);
spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);
list_for_each_entry_safe(tx_buf, tx_buf_tmp,
&hif_dev->tx.tx_pending, 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);
usb_kill_anchored_urbs(&hif_dev->mgmt_submitted);
}