From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E794C2BA83 for ; Fri, 14 Feb 2020 17:50:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E92F206B6 for ; Fri, 14 Feb 2020 17:50:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581702657; bh=72jwIr70tZSmKLso6PZnaN8QwHlfCrUagBq8IFNznWo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vV2VVgqulK2t9OlcVobyIMuLwgtHhhiVWcSuJ1qEgoiqqQ3OLzWu+8lEnD6OTsBRD n+NhFkVljHsdSgreOhWZAy6LJXNrTc3wDAlGqoa7vUTN2rAFfes3O81AukOChvAIsS Vx0Xac7j1M6E8wjp3TAmUN6Y+GXEKVKOdor1wEhY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388771AbgBNP7A (ORCPT ); Fri, 14 Feb 2020 10:59:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:43434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388760AbgBNP7A (ORCPT ); Fri, 14 Feb 2020 10:59:00 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 757C32067D; Fri, 14 Feb 2020 15:58:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581695939; bh=72jwIr70tZSmKLso6PZnaN8QwHlfCrUagBq8IFNznWo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DCpsgHSUWONT3uXS7FOGr+LXEWW8YHK7KMPkCk6gt6CohZEuk65RUbTozM3VCyYwN tz2RZ6S5dQctyfPeQ66YsIKG55ApfT2ckqFxHs1X4L1PDo7FoqGMTi03bR3aP//TE6 /rP8ocurhshBviGWFUfSq/NGdtslMrRrO6xYTF+Y= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yan-Hsuan Chuang , Kalle Valo , Sasha Levin , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.5 473/542] rtw88: fix potential NULL skb access in TX ISR Date: Fri, 14 Feb 2020 10:47:45 -0500 Message-Id: <20200214154854.6746-473-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214154854.6746-1-sashal@kernel.org> References: <20200214154854.6746-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Yan-Hsuan Chuang [ 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 Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin --- 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 a58e8276a41a3..a6746b5a9ff2d 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -832,6 +832,11 @@ 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