linux-kernel - [PATCH 5.4 300/344] rtw88: fix potential NULL skb access in TX ISR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200221072417.143055591@linuxfoundation.org>
Date:   Fri, 21 Feb 2020 08:41:39 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Yan-Hsuan Chuang <yhchuang@...ltek.com>,
        Kalle Valo <kvalo@...eaurora.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.4 300/344] rtw88: fix potential NULL skb access in TX ISR

From: Yan-Hsuan Chuang <yhchuang@...ltek.com>

[ Upstream commit f4f84ff8377d4cedf18317747bc407b2cf657d0f ]

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: e3037485c68e ("rtw88: new Realtek 802.11ac driver")
Signed-off-by: Yan-Hsuan Chuang <yhchuang@...ltek.com>
Signed-off-by: Kalle Valo <kvalo@...eaurora.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/wireless/realtek/rtw88/pci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index d90928be663b9..77a2bdee50fa7 100644
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -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);
-- 
2.20.1