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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B9FBEB64DA for ; Mon, 10 Jul 2023 06:27:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231433AbjGJG07 (ORCPT ); Mon, 10 Jul 2023 02:26:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231462AbjGJG0N (ORCPT ); Mon, 10 Jul 2023 02:26:13 -0400 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED13D1BF; Sun, 9 Jul 2023 23:26:01 -0700 (PDT) X-GND-Sasl: herve.codina@bootlin.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1688970360; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=17ZTBQO+oBIkGul7D/WlB+X7l0VA0KwA6SIv/f89u7w=; b=pIXKjmxfNRP61MN4/M43OLwfOt2eCDwrovK9XTBHcMsO31DUfzfvU6suXBII6V3BYD44tR 1mHUSXcarif+DmleFeC9TIxyD7nNl1T41VZjSwY7CXiuBrPAlN5Hh2AZurhW0lfoaIyaG5 1xj9DgiPLk6f94v/WTAJotVjCsOM/bLTjoFOkYdiI7MGQh0PG2TadiZdbDX2vvcGjEVoMy Y6ydVdRi0Wl/yf0D0ZYMmrGNKOvbYzS6k7Hs5BRQ+B9VLx7sKjZaYgHKg7rFl3+2dErdzm 67ihNd2LivbVVOQPKvRAjm1saYUzLjcHXhq8Y0FLBarhLR+/fRYqKqDr5sOzuA== X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com Received: by mail.gandi.net (Postfix) with ESMTPSA id D7416C0005; Mon, 10 Jul 2023 06:25:58 +0000 (UTC) Date: Mon, 10 Jul 2023 08:25:58 +0200 From: Herve Codina To: Yu Hao Cc: chunfeng.yun@mediatek.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel Subject: Re: [PATCH] usb: mtu3: Fix possible use-before-initialization bug Message-ID: <20230710082558.2f82d607@bootlin.com> In-Reply-To: References: <20230705080625.02b2bac5@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Yu, On Sun, 9 Jul 2023 17:48:15 -0700 Yu Hao wrote: > Hi Hervé, > > Thanks for the comments. How about this patch? > --- > drivers/usb/mtu3/mtu3_gadget_ep0.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/mtu3/mtu3_gadget_ep0.c > b/drivers/usb/mtu3/mtu3_gadget_ep0.c > index e4fd1bb14a55..af2884943c2a 100644 > --- a/drivers/usb/mtu3/mtu3_gadget_ep0.c > +++ b/drivers/usb/mtu3/mtu3_gadget_ep0.c > @@ -600,7 +600,7 @@ static void ep0_tx_state(struct mtu3 *mtu) > mtu3_readl(mtu->mac_base, U3D_EP0CSR)); > } > > -static void ep0_read_setup(struct mtu3 *mtu, struct usb_ctrlrequest *setup) > +static int ep0_read_setup(struct mtu3 *mtu, struct usb_ctrlrequest *setup) > { > struct mtu3_request *mreq; > u32 count; > @@ -608,6 +608,8 @@ static void ep0_read_setup(struct mtu3 *mtu, > struct usb_ctrlrequest *setup) > > csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS; > count = mtu3_readl(mtu->mac_base, U3D_RXCOUNT0); > + if (count == 0) > + return -EINVAL; 'count' should be tested against sizeof(*setup). Indeed, we need to have a setup data packet in the fifo. What do you think about: if (count < sizef(*setup)) return -EINVAL; > > ep0_read_fifo(mtu->ep0, (u8 *)setup, count); > > @@ -642,7 +644,8 @@ __acquires(mtu->lock) > struct mtu3_request *mreq; > int handled = 0; > > - ep0_read_setup(mtu, &setup); > + if (ep0_read_setup(mtu, &setup)) > + return -EINVAL; Forward the error code to the caller ? ret = ep0_read_setup(mtu, &setup) if (ret < 0) return ret; > trace_mtu3_handle_setup(&setup); > > if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) > @@ -764,7 +767,9 @@ irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu) > break; > } > > - ep0_handle_setup(mtu); > + if (ep0_handle_setup(mtu)) > + break; > + Ok > ret = IRQ_HANDLED; > break; > default: Be careful, your patch is wrongly indented. tabs replaced by 4 spaces. You need to keep tabs. Regards, Hervé Codina -- Hervé Codina, Bootlin Embedded Linux and Kernel engineering https://bootlin.com