rtw88: fix potential NULL skb access in TX ISR

[ Upstream commit f4f84ff837 ]

Sometimes the TX queue may be empty and we could possible
dequeue a NULL pointer, crash the kernel. If the skb is NULL
then there is nothing to do, just leave the ISR.

And the TX queue should not be empty here, so print an error
to see if there is anything wrong for DMA ring.

Fixes: e3037485c6 ("rtw88: new Realtek 802.11ac driver")
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yan-Hsuan Chuang 2020-01-07 16:08:07 +08:00 committed by Greg Kroah-Hartman
parent e7e4d0eaa6
commit 034c5f26d2

View file

@ -762,6 +762,11 @@ static void rtw_pci_tx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci,
while (count--) {
skb = skb_dequeue(&ring->queue);
if (!skb) {
rtw_err(rtwdev, "failed to dequeue %d skb TX queue %d, BD=0x%08x, rp %d -> %d\n",
count, hw_queue, bd_idx, ring->r.rp, cur_rp);
break;
}
tx_data = rtw_pci_get_tx_data(skb);
pci_unmap_single(rtwpci->pdev, tx_data->dma, skb->len,
PCI_DMA_TODEVICE);