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 79D50C433EF for ; Tue, 29 Mar 2022 15:57:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239079AbiC2P6w (ORCPT ); Tue, 29 Mar 2022 11:58:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239071AbiC2P6t (ORCPT ); Tue, 29 Mar 2022 11:58:49 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50B1A4D24E for ; Tue, 29 Mar 2022 08:57:07 -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 dfw.source.kernel.org (Postfix) with ESMTPS id E1396612CA for ; Tue, 29 Mar 2022 15:57:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB7B1C340ED; Tue, 29 Mar 2022 15:57:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1648569426; bh=3Xtfj0qdi5cXHLbJKQrGPNIsGSjLL6x0WLhsq+/v46Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OmOYMWUoCDRUBDheu6cIabeycMxE8ZjS8OWKaCZ7bUP1WyIBshy8ru93pCcunhuC2 APv+6B7Qgwnhfkynl8IKjhSimJFM9FiM7N4c7PJ/7y3kw2WpjPvbnwSDZ0RQUmzJMI UG1jPO9nUogrIaJchgZqXVixvvOwiGlDU7zv7dXw= Date: Tue, 29 Mar 2022 17:57:03 +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] staging: r8188eu: check the return value of 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 Fri, Mar 25, 2022 at 02:53:30PM +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 check the return > of it to prevent potential wrong memory access. > > Signed-off-by: Xiaoke Wang > --- > drivers/staging/r8188eu/core/rtw_p2p.c | 2 ++ > drivers/staging/r8188eu/core/rtw_xmit.c | 6 ++++++ > 2 files changed, 8 insertions(+) > > diff --git a/drivers/staging/r8188eu/core/rtw_p2p.c b/drivers/staging/r8188eu/core/rtw_p2p.c > index e2b6cf2..503c4a5 100644 > --- a/drivers/staging/r8188eu/core/rtw_p2p.c > +++ b/drivers/staging/r8188eu/core/rtw_p2p.c > @@ -35,6 +35,8 @@ static u32 go_add_group_info_attr(struct wifidirect_info *pwdinfo, u8 *pbuf) > DBG_88E("%s\n", __func__); > > pdata_attr = kzalloc(MAX_P2P_IE_LEN, GFP_KERNEL); > + if (!pdata_attr) > + return 0; 0 is not an error. Please propagate this error backwards properly. > > pstart = pdata_attr; > pcur = pdata_attr; > diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c > index 46fe62c..1696272 100644 > --- a/drivers/staging/r8188eu/core/rtw_xmit.c > +++ b/drivers/staging/r8188eu/core/rtw_xmit.c > @@ -180,6 +180,10 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter) > pxmitpriv->free_xmit_extbuf_cnt = num_xmit_extbuf; > > rtw_alloc_hwxmits(padapter); > + if (!pxmitpriv->hwxmits) { > + res = _FAIL; > + goto exit; > + } You just leaked memory resources :( How did you test this? > rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry); > > for (i = 0; i < 4; i++) > @@ -1524,6 +1528,8 @@ void rtw_alloc_hwxmits(struct adapter *padapter) > pxmitpriv->hwxmit_entry = HWXMIT_ENTRY; > > pxmitpriv->hwxmits = kzalloc(sizeof(struct hw_xmit) * pxmitpriv->hwxmit_entry, GFP_KERNEL); > + if (!pxmitpriv->hwxmits) > + return; You have to return an error, you can not keep going as if all is well. Please always be VERY careful with these types of fixes. Especially if you have not tested them. thanks, greg k-h