[PATCH 6.1 0892/1146] mISDN: hfcpci: dont call dev_kfree_skb/kfree_skb() under spin_lock_irqsave()

Greg Kroah-Hartman
2022-12-28T16:41:27Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ 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@huawei.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/isdn/hardware/mISDN/hfcpci.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c
index e964a8dd8512..c0331b268010 100644
--- a/drivers/isdn/hardware/mISDN/hfcpci.c
+++ b/drivers/isdn/hardware/mISDN/hfcpci.c
@@ -1617,16 +1617,19 @@ 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);
@@ -1639,10 +1642,12 @@ 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)
--
2.35.1