[PATCH 6.0 0525/1073] hamradio: dont call dev_kfree_skb() under spin_lock_irqsave()

Greg Kroah-Hartman
2022-12-28T16:03:41Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 3727f742915f04f6fc550b80cf406999bd4e90d0 ]

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.

In scc_discard_buffers(), dev_kfree_skb() is called to discard the SKBs,
so replace it with dev_kfree_skb_irq().

In scc_net_tx(), dev_kfree_skb() is called to drop the SKB that exceed
queue length, so replace it with dev_kfree_skb_irq().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/hamradio/scc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hamradio/scc.c b/drivers/net/hamradio/scc.c
index f90830d3dfa6..a9184a78650b 100644
--- a/drivers/net/hamradio/scc.c
+++ b/drivers/net/hamradio/scc.c
@@ -302,12 +302,12 @@ static inline void scc_discard_buffers(struct scc_channel *scc)
spin_lock_irqsave(&scc->lock, flags);
if (scc->tx_buff != NULL)
{
- dev_kfree_skb(scc->tx_buff);
+ dev_kfree_skb_irq(scc->tx_buff);
scc->tx_buff = NULL;
}

while (!skb_queue_empty(&scc->tx_queue))
- dev_kfree_skb(skb_dequeue(&scc->tx_queue));
+ dev_kfree_skb_irq(skb_dequeue(&scc->tx_queue));

spin_unlock_irqrestore(&scc->lock, flags);
}
@@ -1668,7 +1668,7 @@ static netdev_tx_t scc_net_tx(struct sk_buff *skb, struct net_device *dev)
if (skb_queue_len(&scc->tx_queue) > scc->dev->tx_queue_len) {
struct sk_buff *skb_del;
skb_del = skb_dequeue(&scc->tx_queue);
- dev_kfree_skb(skb_del);
+ dev_kfree_skb_irq(skb_del);
}
skb_queue_tail(&scc->tx_queue, skb);
netif_trans_update(dev);
--
2.35.1