This is a note to let you know that I've just added the patch titled mISDN: hfcpci: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: misdn-hfcpci-don-t-call-dev_kfree_skb-kfree_skb-unde.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b95466b6159504889be7ca0f98f51c971e87515a Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Mon Dec 12 16:41:38 2022 +0800 mISDN: hfcpci: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave() [ Upstream commit f0f596bd75a9d573ca9b587abb39cee0b916bb82 ] It is not allowed to call kfree_skb() or consume_skb() from hardware interrupt context or with hardware interrupts being disabled. skb_queue_purge() is called under spin_lock_irqsave() in hfcpci_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. Fixes: 1700fe1a10dc ("Add mISDN HFC PCI driver") Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Reviewed-by: Alexander Duyck <alexanderduyck@xxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c index 89cf1d695a01..e33b58f560bf 100644 --- a/drivers/isdn/hardware/mISDN/hfcpci.c +++ b/drivers/isdn/hardware/mISDN/hfcpci.c @@ -1631,16 +1631,19 @@ hfcpci_l2l1D(struct mISDNchannel *ch, struct sk_buff *skb) test_and_clear_bit(FLG_L2_ACTIVATED, &dch->Flags); spin_lock_irqsave(&hc->lock, flags); if (hc->hw.protocol == ISDN_P_NT_S0) { + struct sk_buff_head free_queue; + + __skb_queue_head_init(&free_queue); /* prepare deactivation */ Write_hfc(hc, HFCPCI_STATES, 0x40); - skb_queue_purge(&dch->squeue); + skb_queue_splice_init(&dch->squeue, &free_queue); if (dch->tx_skb) { - dev_kfree_skb(dch->tx_skb); + __skb_queue_tail(&free_queue, dch->tx_skb); dch->tx_skb = NULL; } dch->tx_idx = 0; if (dch->rx_skb) { - dev_kfree_skb(dch->rx_skb); + __skb_queue_tail(&free_queue, dch->rx_skb); dch->rx_skb = NULL; } test_and_clear_bit(FLG_TX_BUSY, &dch->Flags); @@ -1653,10 +1656,12 @@ hfcpci_l2l1D(struct mISDNchannel *ch, struct sk_buff *skb) hc->hw.mst_m &= ~HFCPCI_MASTER; Write_hfc(hc, HFCPCI_MST_MODE, hc->hw.mst_m); ret = 0; + spin_unlock_irqrestore(&hc->lock, flags); + __skb_queue_purge(&free_queue); } else { ret = l1_event(dch->l1, hh->prim); + spin_unlock_irqrestore(&hc->lock, flags); } - spin_unlock_irqrestore(&hc->lock, flags); break; } if (!ret)