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 BE18CC433EF for ; Thu, 31 Mar 2022 06:03:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230350AbiCaGFC (ORCPT ); Thu, 31 Mar 2022 02:05:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230033AbiCaGFA (ORCPT ); Thu, 31 Mar 2022 02:05:00 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9A311D41A5 for ; Wed, 30 Mar 2022 23:03:13 -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 5C51CB81EA0 for ; Thu, 31 Mar 2022 06:03:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6E4FC340ED; Thu, 31 Mar 2022 06:03:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1648706591; bh=A0m+Ep1Uons0hoytgDZ+0JywZF4PGusJ+GkrcK012yk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MLrgOnwSctG+gm6aPt7XUieMGp8JxaThqmsq5M+Y0SN3UAmkZX/W7s2RYLYk7J/tO aRGSNDA1IYzqtgKQMrUer0TzbsGCx3WsAArVeL27deJwzheoHrSSMcdZowfOjzxCjW btqPzaWcNO3DSd+gu8AvHke6bT9EgEOV/KAh55c8= Date: Thu, 31 Mar 2022 08:03:08 +0200 From: Greg KH To: xkernel.wang@foxmail.com Cc: Larry.Finger@lwfinger.net, phil@philpotter.co.uk, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] staging: r8188eu: properly handle the kzalloc() Message-ID: References: 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 Wed, Mar 30, 2022 at 11:16:07PM +0800, xkernel.wang@foxmail.com wrote: > From: Xiaoke Wang > > kzalloc() is a memory allocation function which can return NULL when > some internal memory errors happen. So it is better to handle the return > of it to prevent potential wrong memory access. > For the kzalloc() in go_add_group_info_attr(), since there is a lack > of error handlers along the call chain it lies and the lifetime of > `pdata_attr` is only in go_add_group_info_attr(), `pdata_attr` is roughly > changed to a local variable on stack like the other functions in > rtw_p2p.c, such as `u8 p2pie[MAX_P2P_IE_LEN] = { 0x00 };` in > issue_p2p_presence_resp(). > > Signed-off-by: Xiaoke Wang > --- > drivers/staging/r8188eu/core/rtw_p2p.c | 6 ++---- > drivers/staging/r8188eu/core/rtw_xmit.c | 12 +++++++++--- > drivers/staging/r8188eu/include/rtw_xmit.h | 2 +- > 3 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/drivers/staging/r8188eu/core/rtw_p2p.c b/drivers/staging/r8188eu/core/rtw_p2p.c > index e2b6cf2..f1a5df8 100644 > --- a/drivers/staging/r8188eu/core/rtw_p2p.c > +++ b/drivers/staging/r8188eu/core/rtw_p2p.c > @@ -27,15 +27,14 @@ static u32 go_add_group_info_attr(struct wifidirect_info *pwdinfo, u8 *pbuf) > struct list_head *phead, *plist; > u32 len = 0; > u16 attr_len = 0; > - u8 tmplen, *pdata_attr, *pstart, *pcur; > + u8 pdata_attr[MAX_P2P_IE_LEN] = { 0x00 }; You just created a huge variable on the stack. Are you _SURE_ that is ok? Have you tested this change to make sure it works? If not, I can't take it, sorry. greg k-h