This is a note to let you know that I've just added the patch titled hamradio: don't call dev_kfree_skb() under spin_lock_irqsave() to the 5.15-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: hamradio-don-t-call-dev_kfree_skb-under-spin_lock_ir.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6ac90072bd014896cb3b344251796571ceae239e Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Thu Dec 8 22:21:46 2022 +0800 hamradio: don't call dev_kfree_skb() under spin_lock_irqsave() [ 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@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/hamradio/scc.c b/drivers/net/hamradio/scc.c index e0bb131a33d7..39db3cae4dd1 100644 --- a/drivers/net/hamradio/scc.c +++ b/drivers/net/hamradio/scc.c @@ -301,12 +301,12 @@ 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);