From patchwork Thu Dec 21 15:16:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krishna Kurapati X-Patchwork-Id: 13502245 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DF184E1B0; Thu, 21 Dec 2023 15:16:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="oCV4Ghlm" Received: from pps.filterd (m0279869.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.24/8.17.1.24) with ESMTP id 3BLEur8K012177; Thu, 21 Dec 2023 15:16:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding:content-type; s=qcppdkim1; bh=KxELH7v 9ITZOwsllWmWfZmzJThagjN0t4hjGlBiSjc4=; b=oCV4Ghlm96tCyPXkKLf4ccw FHNhKPc8QMqGnHUa7px5hmUpmhP+js19SF+wBJ8v6xZDse5Gnt2gX6W9GiMAgDWm Z7XS/oTv1fZsAE7tdmYUe6evIEjIjfqAK5l796c5Xjl9DKffN39nsHys8cN/H5BI hWKEyr593jxM/ETKREhaODEZWDtUnecpWLHiu1exvPJ/doiBCyWwqH/tQQZrguZA QebIOI7AcoS7BoHi1LOWISVTuY2DMxeifOnAO+jCWPeWQh1YPRv/ufeJK0HE7NEn KkcG5bachFT/JM1wLK3DpjMVD3I/OIlxB1xHIsbv09G0+1sTmiH5Aqm81k+W/zg= = Received: from nalasppmta01.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3v4pq386pw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 21 Dec 2023 15:16:34 +0000 (GMT) Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3BLFGXJZ013592 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 21 Dec 2023 15:16:33 GMT Received: from hu-kriskura-hyd.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Thu, 21 Dec 2023 07:16:30 -0800 From: Krishna Kurapati To: Thinh Nguyen , Greg Kroah-Hartman CC: , , , , Krishna Kurapati Subject: [PATCH v2] usb: dwc3: gadget: Ignore dwc3 interrupt if GEVNTCOUNT reads corrupt value Date: Thu, 21 Dec 2023 20:46:20 +0530 Message-ID: <20231221151620.16030-1-quic_kriskura@quicinc.com> X-Mailer: git-send-email 2.42.0 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: Em5qpkGqSDNHFIOHKxtysObEv8P-wvrO X-Proofpoint-ORIG-GUID: Em5qpkGqSDNHFIOHKxtysObEv8P-wvrO X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-09_02,2023-12-07_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 phishscore=0 lowpriorityscore=0 bulkscore=0 spamscore=0 mlxscore=0 clxscore=1015 impostorscore=0 mlxlogscore=842 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2311290000 definitions=main-2312210115 In the current implementation, the check_event_buf call reads the GEVNTCOUNT register to determine the amount of event data generated and copies it from ev->buf to ev->cache after masking interrupt. During copy if the amount of data to be copied is more than (length - lpos), we fill the ev->cache till the end of 4096 byte buffer allocated and then start filling from the top (lpos = 0). In one instance of SMMU crash it is observed that GEVNTCOUNT register reads more than 4096 bytes: dwc3_readl base=0xffffffc0091dc000 offset=50188 value=63488 (offset = 50188 -> 0xC40C) -> reads 63488 bytes As per crash dump: dwc->lpos = 2056 and evt->buf is at 0xFFFFFFC009185000 and the crash is at 0xFFFFFFC009186000. The diff which is exactly 0x1000 bytes. We first memcpy 2040 bytes from (buf + lpos) to (buf + 0x1000). And then we copy the rest of the data (64388 - 2040) from beginning of dwc->ev_buf. While doing so we go beyond bounds as we are trying to memcpy 62348 bytes into a 4K buffer resulting in crash. Fix this by ignoring the interrupt when GEVNTCOUNT register reads a value more than the event ring allocated. Signed-off-by: Krishna Kurapati --- Changes in v2: Instead of fixing amount of data being copied from ring, ignored the interrupt when count is corrupt as per suggestion from Thinh. Link to v1: https://lore.kernel.org/all/20230521100330.22478-1-quic_kriskura@quicinc.com/ drivers/usb/dwc3/gadget.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 858fe4c299b7..e27933fdcce3 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4451,6 +4451,7 @@ static irqreturn_t dwc3_thread_interrupt(int irq, void *_evt) static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) { struct dwc3 *dwc = evt->dwc; + int ret = IRQ_WAKE_THREAD; u32 amount; u32 count; @@ -4480,6 +4481,12 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) if (!count) return IRQ_NONE; + if (count > evt->length) { + dev_err(dwc->dev, "GEVTCOUNT corrupt\n"); + ret = IRQ_NONE; + goto done; + } + evt->count = count; evt->flags |= DWC3_EVENT_PENDING; @@ -4493,9 +4500,10 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) if (amount < count) memcpy(evt->cache, evt->buf, count - amount); +done: dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count); - return IRQ_WAKE_THREAD; + return ret; } static irqreturn_t dwc3_interrupt(int irq, void *_evt)