• Yang Yingliang's avatar
    mISDN: hfcsusb: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave() · ddc9648d
    Yang Yingliang authored
    It is not allowed to call kfree_skb() or consume_skb() from hardware
    interrupt context or with hardware interrupts being disabled.
    
    It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
    The difference between them is free reason, dev_kfree_skb_irq() means
    the SKB is dropped in error and dev_consume_skb_irq() means the SKB
    is consumed in normal.
    
    skb_queue_purge() is called under spin_lock_irqsave() in hfcusb_l2l1D(),
    kfree_skb() is called in it, to fix this, use skb_queue_splice_init()
    to move the dch->squeue to a free queue, also enqueue the tx_skb and
    rx_skb, at last calling __skb_queue_purge() to free the SKBs afer unlock.
    
    In tx_iso_complete(), dev_kfree_skb() is called to consume the transmitted
    SKB, so replace it with dev_consume_skb_irq().
    
    Fixes: 69f52adb ("mISDN: Add HFC USB driver")
    Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
    Reviewed-by: default avatarAlexander Duyck <alexanderduyck@fb.com>
    Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    ddc9648d
hfcsusb.c 54.3 KB