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 C35E6C43334 for ; Thu, 30 Jun 2022 11:09:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234411AbiF3LJg (ORCPT ); Thu, 30 Jun 2022 07:09:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbiF3LJf (ORCPT ); Thu, 30 Jun 2022 07:09:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE8D543EC4; Thu, 30 Jun 2022 04:09:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A264AB82A22; Thu, 30 Jun 2022 11:09:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FE09C34115; Thu, 30 Jun 2022 11:09:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656587371; bh=QZ6v7tJvZDnDS4E3NPYQseW8/iFcyjFOm1Qn6vFL/T0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bNJnP44bQ6i2KTGfBEgrGO4Jj+/z2LKcj1ym5rqOCXkI5tE8XA3e5jf/ECLOaOqEi qQ77I7f9shRrMXwFyZKgLc6iBZfuxwOxPLKF2EXpiqTR4OEFt98Cg4qcjf4Am9wexE s6SgRkgAF+DpDmZIKKjNyyStAv14WnqTy1i2X3qE= Date: Thu, 30 Jun 2022 13:09:28 +0200 From: Greg Kroah-Hartman To: Sebin Sebastian Cc: kernel test robot , Neal Liu , Felipe Balbi , Joel Stanley , Andrew Jeffery , linux-aspeed@lists.ozlabs.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 -next] usb: gadget: dereference before null check Message-ID: References: <20220630044706.10772-1-mailmesebin00@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 30, 2022 at 04:33:42PM +0530, Sebin Sebastian wrote: > On Thu, Jun 30, 2022 at 08:54:04AM +0200, Greg Kroah-Hartman wrote: > > On Thu, Jun 30, 2022 at 10:17:06AM +0530, Sebin Sebastian wrote: > > > Fix coverity warning dereferencing before null check. _ep and desc is > > > dereferenced on all paths until the check for null. Move the > > > initializations after the check for null. > > > > How can those values ever be NULL? > > > > > Coverity issue: 1518209 > > > > > > Reported-by: kernel test robot > > > > kernel test robot did not find this issue. > > > After I submitted the PATCH v1, kernel test robot ran some tests and > produced a report of the things that I broke while creating the patch. > That's why I kept this tag. Yes, but the kernel test robot reported your first patch was broken, not that this commit itself was reported by that. Please drop that, it's confusing I know, and trips lots of people up, but is not needed here. > > > > Signed-off-by: Sebin Sebastian > > > > What commit id does this change fix? > > > So should I provide the commit ID of the patch v1 that kernel > test robot referred to? No, report the commit id that this commit you are creating fixes. It had to be added to the tree sometime in the past, right? > > > > --- > > > Changes since v1: Fix the build errors and warnings due to first patch. > > > Fix the undeclared 'ep' and 'maxpacket' error. Fix the ISO C90 warning. > > > > > > drivers/usb/gadget/udc/aspeed_udc.c | 21 ++++++++++++++------- > > > 1 file changed, 14 insertions(+), 7 deletions(-) > > > > > > diff --git a/drivers/usb/gadget/udc/aspeed_udc.c b/drivers/usb/gadget/udc/aspeed_udc.c > > > index d75a4e070bf7..a43cf8dde2a8 100644 > > > --- a/drivers/usb/gadget/udc/aspeed_udc.c > > > +++ b/drivers/usb/gadget/udc/aspeed_udc.c > > > @@ -341,26 +341,33 @@ static void ast_udc_stop_activity(struct ast_udc_dev *udc) > > > static int ast_udc_ep_enable(struct usb_ep *_ep, > > > const struct usb_endpoint_descriptor *desc) > > > { > > > - u16 maxpacket = usb_endpoint_maxp(desc); > > > - struct ast_udc_ep *ep = to_ast_ep(_ep); > > > > checking that ep is NULL here is an impossible thing on its own. You > > did change this so that you didn't check this anymore, which is odd as > > you did not mention that in the changelog text :( > > > Yes, I missed the checking for ep. I thought of checking it after > initilizing ep. > > > > - struct ast_udc_dev *udc = ep->udc; > > > - u8 epnum = usb_endpoint_num(desc); > > > unsigned long flags; > > > u32 ep_conf = 0; > > > u8 dir_in; > > > u8 type; > > > + u16 maxpacket; > > > + struct ast_udc_ep *ep; > > > + struct ast_udc_dev *udc; > > > + u8 epnum; > > > > Why did you reorder these? > > > This is actually the original order that these were in. I reordered it > while creating the first patch, then I changed it back to the original > order they were in the source tree for this patch. So this patch does not apply cleanly on linux-next? We did not apply your intermediate, broken, patch for obvious reasons, so you can not send a change on top of that, right? > > > > > > - if (!_ep || !ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT || > > > - maxpacket == 0 || maxpacket > ep->ep.maxpacket) { > > > + if (!_ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) { > > > EP_DBG(ep, "Failed, invalid EP enable param\n"); > > > return -EINVAL; > > > } > > > - > > > > Why did you remove this line? > > > I removed the check for maxpacket because it is not initialized in this > part, the check for the same thing comes after initialization. > This is the check for that, this is also included in the patch. > + if (maxpacket == 0 || maxpacket > ep->ep.maxpacket) { > + EP_DBG(ep, "Failed, invalid EP enable param\n"); > + return -EINVAL; > + } > Should I add the check for 'ep' in this part? > > > Also, your To: line is messed up somehow, please fix your email > > client... > > > Ok, I will surely do it. > > > thanks, > > > > gre gk-h > > I did many mistakes in the patch v1, so I had to bring this patch to the > original state things were. I left all the declarations in the same > order (which made it seem like reordering) and moved the initialization > part after the check for _ep and desc. Perhaps you might want to start out doing coding style cleanups in drivers/staging/* to get the process of how to submit patches properly and test your changes before sending them out, before going out into the real part of the kernel. thanks, greg k-h